20080915 Ver 1_Application_20080605

* Duke
Energy®
Carolinas
June 5, 2008
North Carolina Division of Water Quality
Attention: John Dorney
Wetlands Program Development Unit
Parkview Building
2321 Crabtree Blvd. Suite 250
Raleigh, NC 27604
Re: FERC 401 Water Quality Certification Application
Catawba - Wateree Hydroelectric Project
FERC Project No. 2232
Dear Mr. Dorney:
STEVEN D. JESTER, AlA
Vice President
Hydro Licensing and Lake Services
Duke Energy Carolinas, LLC
526 South Church St.
Charlotte, NC 28202
Mailing Address:
EC12K / PO Box 1006
Charlotte, NC 28201 -1006
704 .382 4887
704 562 5850 cell
sjester @duke- energy. corn
Duke Energy Carolinas, LLC (Duke) operates the Catawba - Wateree Hydroelectric
Project (Project), which is licensed as Federal Energy Regulatory Commission (FERC)
Project No. 2232. Duke is required to obtain a new license from the FERC in order to
continue operating the Project. The federal action of issuing a new license for the
Project triggers the need for Duke to also obtain a water quality certification pursuant to
Section 401 of the Clean Water Act.
The Application for New License was submitted to the FERC on August 29, 2006, along
with a Comprehensive Relicensing Agreement (CRA), signed by 70 stakeholder
organizations. The FERC has been reviewing the application and the CRA since their
submittal and, as part of the relicensing process, issued a "Ready for Environmental
Analysis" (REA) notice on April 7, 2008. Duke is required to submit an application for
water quality certification in accordance with the requirements of the Federal Power Act
within 60 days following the REA notice (June 6, 2008). The subject of this certification is
the continued operation of the Project under a new FERC- issued license that is
consistent with applicable sections of the Catawba - Wateree CRA.
Enclosed are one original and six copies of a complete application package for the
Section 401 water quality certification of the Project and a check for fee payment in the
amount of $570.00 payable to the North Carolina Division of Water Quality (NCDWQ).
The enclosed application package is intended to provide the reasonable assurance
necessary for the NCDWQ to certify that, upon implementing the proposed flow and
water quality modifications included in the CRA, Duke will be able to meet applicable
water quality standards when operating the Project under a new FERC operating license
consistent with applicable CRA provisions. Each application package includes:
www.duke- energy.com

Mr. John Dorney
June 5, 2008
Page 2
A complete and signed FERC 401 Water Quality Certification Application
form as required by the North Carolina Division of Water Quality
A Supplemental Information Package that presents detailed explanations of:
• The Catawba - Wateree Hydroelectric Project
• The Catawba - Wateree Relicensing Process
• The Catawba - Wateree Comprehensive Relicensing Agreement
• The water quality assessment methodologies utilized by Duke
• Plant -by -plant descriptions of proposed equipment and operational
modifications and projected compliance with applicable state water quality
standards
• Streamflow mitigation calculations
• An assessment of water quality certification criteria, including cumulative
impacts
• Supporting appendices, including the Quality Assurance Project Plan
(QAPP)
• Historical water quality data collected by Duke
If there are questions or if further information is required, please contact Mark Oakley
(704- 382 -0293, emoakleyC@_duke- energy.com) or Tami Styer 704 - 382 -0293,
tsstyerCo) -d uke- energy. com).
Sincerely,
Steven D. Jester, Vice President
Hydro Licensing and Lake Services
Duke Energy Carolinas, LLC
bcc: Jeff Lineberger, Duke Energy Carolinas, LLC
Mark Oakley, Duke Energy Carolinas, LLC
Tami Styer, Duke Energy Carolinas, LLC
Garry Rice, Duke Energy Carolinas, LLC
Carol Goolsby, Duke Energy Carolinas, LLC
George Galleher, Duke Energy Carolinas, LLC
Scott Fletcher, Devine Tarbell and Associates
John Whittaker, Winston and Strawn

CATAWBA - WATEREE HYDROELECTRIC
PROJECT (FERC No. 2232)
SECTION 401 WATER QUALITY CERTIFICATION
APPLICATION TO THE NORTH CAROLINA
DIVISION OF WATER QUALITY
Charlotte, North Carolina
JUNE 2008
RIM

NC 401 Water Quality Certification Application
DWQ ID:
FERC 401 WATER QUALITY CERTIFICATION
APPLICATION
For existing Federal Energy Regulatory Commission (FERC) Permits,
*SEND SEVEN (7) COPIES AND THE APPROPRIATE FEE (SEE ITEM # 16* OF THIS
APPLICATION) TO:
THE NC DIVISION OF WATER QUALITY
ATTN: JOHN DORNEY
2321 CRABTREE BLVD., SUITE 250
RALEIGH, NC 27604
(PLEASE PRINT OR TYPE)
1. OWNER'S NAME:
Duke Energy Carolinas, LLC ( "Duke ")
2. MAILING ADDRESS:
Duke Energy Carolinas, LLC
c/o Mark Oakley, P.E.
526 South Church Street, P.O. Box 1006, Mail Code EC 12Y
CITY: Charlotte STATE: North Carolina ZIP CODE: 28201 -1006
PROJECT NAME:
Catawba - Wateree Hydroelectric Project, FERC No. 2232 (the Project) consisting of the
following developments in North Carolina:
• Bridgewater Development
• Rhodhiss Development
• Oxford Development
• Lookout Shoals Development
• Cowans Ford Development
• Mountain Island Development
• Wylie Development
1

NC 401 Water Quality Certification Application
The Federal Energy Regulatory Commission (FERC) defines the "Project' as all 11
Catawba - Wateree reservoir developments in North Carolina and South Carolina. Duke
utilizes this same terminology in this application and the accompanying Supplemental
Information Package. The federal action triggering the need to obtain this 401 Water Quality
Certification is the issuance of a new operating license for the Catawba - Wateree Project by
the FERC. Therefore, the subject of the certification being sought is the continued operation
of the Project under a new FERC license that is consistent with the applicable sections of the
Catawba - Wateree Comprehensive Relicensing Agreement (CRA). The CRA and its
applicable sections are discussed in more detail in Section 3.5 of the accompanying
Supplemental Information Package.
PROJECT LOCATION ADDRESS (IF DIFFERENT FROM MAILING ADDRESS
ABOVE):
■ Bridgewater Development, 5790 Power House Road, Morganton, NC 28655
■ Rhodhiss Development, 109 Power House Road, Rhodhiss, NC 28667
■ Oxford Development, 6874 Hwy 16 North, Conover, NC 28613
■ Lookout Shoals Development, 678 Lookout Dam Road, Statesville, NC 28625
■ Cowans Ford Development, 257 Duke Lane, Stanley, NC 28164
■ Mountain Island Development, 439 Mtn. Island Road, Mt. Holly, NC 28120
3. TELEPHONE NUMBER: (WORK)
For questions or additional information concerning any of the following developments,
please contact Mark Oakley at (704) 382 -5778.
■ Bridgewater Development
■ Rhodhiss Development
■ Oxford Development
■ Lookout Shoals Development
■ Cowans Ford Development
■ Mountain Island Development
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NC 401 Water Quality Certification Application
■ Wylie Development
4. IF APPLICABLE: AGENT'S NAME OR RESPONSIBLE CORPORATE
OFFICIAL, ADDRESS, PHONE NUMBER:
Marls Oakley, P.E.
Catawba - Wateree Relicensing Project Manager
Duke Energy - Hydro Licensing
526 South Church Street, Mail Code EC 12Y
Charlotte, NC 28202
(704) 382 -5778
E -mail: emoaldeygduke- energy.com
5. LOCATION OF PROJECT (PROVIDE A MAP, INCLUDING A COPY OF USGS
TOPOGRAPHIC MAP OR AERIAL PHOTOGRAPHY WITH SCALE): COUNTY:
NEAREST TOWN:
SPECIFIC LOCATION (INCLUDE ROAD NUMBERS, LANDMARKS, ETC.)
Table 1. Location of Project.
See Supplemental Information Package Sections 5.1 through 5.6 for location and
topographic maps.
County
Development
(Powerhouse
Nearest Town
Landmark (Distances are approximate)
Location)
Bridgewater
Burke
Morganton
1.5 miles northeast of the intersection of NC State
Route 70 East and Bridgewater Road.
Rhodhiss
Caldwell
Rhodhiss
3.5 miles nortfivest of the Hickory Municipal Airport.
6.2 miles south of the intersection of NC State Route
Oxford
Catawba
Conover
16 and NC State Route 64.
1.3 miles north of the intersection of NC State Route
Lookout Shoals
Iredell
Statesville
NC 10 and US Interstate 40.
2.4 miles southeast of the intersection of NC State
Cowan Ford
Lincoln
Stanlev
Route 16 and NC State Route 73.
1.75 miles south of the intersection of NC State Route
Mountain Island
Gaston
Mt. Holly
16 and NC State Route 273.
3.0 miles north of the intersection of NC State Route 16
WvIie
York
Fort Mill
and US Interstate 77
See Supplemental Information Package Sections 5.1 through 5.6 for location and
topographic maps.

NC 401 Water Quality Certification Application
6. IMPACTED STREAM /RIVER: Catawba - Wateree RIVER BASIN: Catawba - Wateree
CURRENT DIVISION OF WATER QUALITY (DWQ) CLASSIFICATION:
Table 2: Designated uses and water quality assessments for reservoirs and river reaches in the Catawba River
Basin.'
Reservoir/River Reach
Designated Use
Mean Depth
Full Pond Surface Area
Classifications
(ft)
(ac)
Assigned by the
NCDENR -DWQ
Lake James
WS -V, B
44.3
6,754
Linville River: below
WS -V
N/A
N/A
Bridgewater Hydro to
0.6 mi upstream of Muddy
Creek confluence
Linville and Catawba
WS -IV: Tr
N/A
N/A
rivers: below
Bridgewater Hydro to
headwaters of Lake
Rlrodhiss
Lake Rhodhiss
WS -IV, B: CA
20.6
2,724
Lake Hickoiv
WS -IV, B: CA
31.1
4,072
(depending on location)
WS -V, B
(depending on location)
Lookout Shoals Lake
WS -IV, B: CA
24.6
1,155
Lake Norman
WS -IV, B: CA
33.5
32,339
Mountain Island Lake
WS -IV, B: CA
17.7
3,117
Lake WN-lie
WS -IV, B: CA
22.9
12,177
(depending on location)
WS -V, B
(depending on location)
Classifications and assessments are from the North Carolina 1998 -1999 305(b) report (NCDENR -DWQ 2000.
Sources of impairments are listed in parentheses.
Definitions of designated use classifications:
C (North Carolina): Freshwaters protected for secondary recreation. fishing and aquatic life including propagation
and suivival, and wildlife.
B (North Carolina): Freshwaters protected for primary recreation, which includes swimming on a frequent or
organized basis and all Class C uses.
WS L• Waters protected for all Class C uses plus waters used as sources of water supply for drinking, culinary, or
food processing purposes for those users desiring maximum protection for their water supplies.
WS IL• Waters used as sources of water supply for drinking, culinary, or food processing purposes where a WS -I
classification is not feasible. These waters are also protected for Class C uses.
WS III: Waters used as sources of water supply for drinking, culinary, or food processing purposes where a more
protective WS -I or II classification is not feasible. These waters are also protected for Class C uses.
WS IV: Waters used as sources of water supply for drinking, culinary, or food processing purposes where a WS -I,
II or III classification is not feasible. These waters are also protected for Class C uses.
WS V: Waters protected as water supplies which are generally upstream and draining to Class WS -IV waters or
waters used by industry to supply their employees with drinking water or as waters formerly used as water supply.
These waters are also protected for Class C uses.
CA: Water Supply Critical Area, the area adjacent to a water supply intake or reservoir where risk associated with
pollution is greater than from the remaining portions of the watershed.
4

NC 401 Water Quality Certification Application
7. (a) IS THE PROJECT LOCATED WITHIN A NORTH CAROLINA DIVISION OF
COASTAL MANAGEMENT AREA OF ENVIRONMENTAL CONCERN (AEC)?
No. The developments are outside and upstream of the AEC.
(b) IF THE PROJECT IS LOCATED WITHIN A COASTAL COUNTY (SEE PAGE
7 FOR LIST OF COASTAL COUNTIES), WHAT IS THE LAND USE PLAN (LUP)
DESIGNATION? Not applicable
8. (a) ARE ADDITIONAL PERMIT REQUESTS EXPECTED FOR THIS PROPERTY
IN THE FUTURE? Yes
IF YES, DESCRIBE ANTICIPATED WORK:
Other than constricting a new powerhouse at the Bridgewater Development, this
application does not contemplate land - disturbing activities or constriction (dredging or
filling) work within the waters of the Project. The implementation of water quality related
requirements will begin upon receiving certifications from North Carolina and South
Carolina and a New License from the FERC. Therefore, stormwater control measures are
not applicable for this application. Necessary constriction- related permits and certifications
for the new Bridgewater Powerhouse constriction project as well as any other activities
requiring dredge or fill permits to implement other provisions of the CRA will be applied
for separately.
9. (a) ESTIMATED TOTAL NUMBERS OF ACRES IN PROJECT:
Refer to Item 11, Table 6 of this application.
10. PROVIDE AN APPROPRIATE ENVIRONMENTAL DOCUMENT. THE
DOCUMENT SHOULD ADDRESS:
(a) DATA SHOWING THAT A 7Q10 MINIMUM FLOW WILL BE PROVIDED
Stream flow records on the Catawba and Wateree rivers reflect only the regulated
operations and reservoir management of the hydroelectric stations, including extreme low
flow conditions when the hydro stations have historically released no flow other than
leakage flow between peak electric demand periods. Therefore, the available 7Q10 statistic
has little relevance in establishing a natural flow threshold level.
5

NC 401 Water Quality Certification Application
In lieu of 7Q10 flows, detailed resource assessments were conducted. The resulting aquatic
flow needs were balanced with other water use needs in order to be sustainable into the
future while meeting resource agency protection, mitigation and enhancement goals. At
some locations, the hydroelectric station releases directly into the downstream reservoir
and no riverine environment exists. At some locations, aquatic resource improvements
were achieved but do not fully meet resource agency goals, and for those locations,
additional mitigation is being provided as described in Section 6 of the accompanying
Supplemental Information Package.
For each development, operational changes, mechanical installations, and /or upgrades are
proposed to provide minimum flows in accordance with the Flow and Water Quality
Implementation Plan (FWQIP) contained in Appendix L of the Catawba - Wateree CRA and
as shown on Table 4 (Section 10(d)) of this application form.
(b) A COST BENEFIT ANALYSIS OF THE PROJECT SHOWING WHY THE
PROJECT IS STILL NECESSARY
The continued operation of the Catawba - Wateree Project has no practical alternative.
Fourteen counties and more than 30 municipalities depend now and in the future on the
following critical benefits provided by the Project that cannot be practically replaced:
■ Energy: In addition to currently providing the energy to power 116,000 homes (on an
average yearly basis) and water to support over 8,100 megawatts (MW) of fossil and
nuclear - fueled power plants (44 percent of Duke's North Carolina and South Carolina
generating fleet), the Catawba - Wateree River is a critical component in meeting future
electric supply needs. Duke's system demand for electricity in North Carolina and
South Carolina is expected to more than double over the next 50 years and a substantial
portion of that new generation capacity is expected to rely on the Catawba - Wateree
River.
6

NC 401 Water Quality Certification Application
■ Drinking Water: The Catawba - Wateree River provides a reliable drinking water supply
for over 13 million people. Future public water supply needs are projected to increase
over 200 percent in the next 50 years.
■ Jobs: The Catawba - Wateree River also provides a reliable water supply that is vital to
the operations of several large industrial facilities, a key component to the economic
vitality of the region.
From an economic cost - benefit perspective, the benefits of the Project as a resource for
both electric capacity and energy can be expressed in terms of avoided costs. For the
purposes of this application, avoided costs are energy, capacity, and severance fees that
would be incurred if Duke's certification request was denied. Certification denial would
result in a loss of the FERC license. A Project takeover by another applicant would impact
Duke, its customers, and its investors in many ways. Since the Project is a component of a
power system mix that consists of multiple types of generation with various fuel sources,
impacts extend beyond the value of the firm capacity and energy contribution from the
Project itself. The full extent of actual severance damages would be dependent upon the
details of the system separation, assets involved, the characteristics of the replacement
power source, and the compensation mechanism used to reimburse Duke for the system
value lost due to removing the power and reliability provided by the Project. Since many
of these details are uncertain, some simplification and assumptions must be made in
preparing an estimate. For purposes of this application, the severance damage calculation
has been limited to estimates of the value lost and additional costs incurred by severing the
Project from the system and by replacing it with an alternative hydro generation resource.
Severance damages are estimated to be $1,076,083,338 in 2006 dollars.
If a certification or license were not granted, alternative power would be obtained from
other resources within Duke's generation system or from purchased power. Under normal
conditions, either of these resources should be capable of providing the necessary
replacement energy, although at a higher system price and with higher air and water
emission implications.
7

NC 401 Water Quality Certification Application
Duke would incur various costs in replacing the power output from the licensed Project
with alternative generation and /or purchased power. Actual replacement costs would
depend on many factors including the replacement source, location, fuel type, and
availability. For purposes of a severance damage calculation, the alternative has been
assumed to be replacement with a storage hydro project that is connected to the
transmission grid and is being compensated at current SCHEDULE PP -H (NC) 15 -year
fixed rates. The Catawba - Wateree Project consists of 13 hydroelectric stations located on
11 reservoirs. The generation characteristics of each hydroelectric station in the Project
were used to define the generation profiles for the alternative resources to duplicate a
replacement in kind. The stations located on common impoundments (Great Falls -
Dearborn and Rocky Creek -Cedar Creek) are treated as single generation and transmission
entities due to the shared water source and some common equipment and cost components.
The methodology used to estimate replacement costs uses two cost components: energy
cost and capacity cost. The SCHEDULE PP -H (NC) rate stricture is designed to provide
compensation for both of these components on a generation profile basis. Historical
generation records, profiles for the stations in the Project, and results of recent
modifications have been combined to calculate a current year value of Project power
estimate of $86,427,034 in 2006 dollars. The current average annual cost of power
produced by the Project is $45,321,369 as shown in the calculations within Section H3.1 of
Exhibit H and Section D4.0 of the Application for New License, filed with FERC on
August 26, 2006. This figure contains an annual cost component for capital charges that
would be recovered within the net investment recovery in the event of Project takeover.
The annual avoided operating costs are $22,324,345 with the cost of capital removed. The
difference between the $86,427,034 value of power estimate and the $22,324,345 avoided
operating costs is $64,102,688. This is the current annual cost of replacing Project
generation.
Applying appropriate inflation and discount rates to the current annual cost of replacing
Project generation over a reasonable license period could be used to estimate the generation
9

NC 401 Water Quality Certification Application
component of severance damages. Generation severance damage cost for the period 2006—
2045 is estimated to be $1,040,088,071
In addition to costs incurred from generation severance, Duke would incur costs from
transmission facility severance damages. These are the values of the equipment lost, the
costs of certain system modifications that would be required to maintain reliable and
functional service, and the costs that would be incurred in providing transmission system
interconnection for a new owner. Transmission system interconnection cost represents
those efforts necessary to establish a terminal position complete with all required protective
devices, switches, bus, wiring, support strictures, relaying, controls, metering, and
telemetry to reliably accommodate interconnection and to monitor energy delivered to the
transmission system.
The Catawba - Wateree Project transmission severance damages are estimated to be
$26,110,232 for separation expenses and $9,885,035 for interconnection costs, yielding a
total transmission system severance damage estimate of $35,995,267 in 2006 dollars.
Detailed information regarding these calculations can be found in the Application for New
License Exhibit D: Report on cost and financing and Exhibit H: Report on Supplemental
Information.
(c) DESCRIPTION OF LENGTH OF BYPASS REACH (IF ANY) AND
MEASURES TO PROVIDE FLOW TO THE REACH IN LOW FLOW
CONDITIONS.
The only bypassed reaches in North Carolina associated with the Project are located
below the Catawba Dam and the Paddy Creek Dam (both of which are at Lake James), and
the Mountain Island Dam. Flows currently within all three bypassed reaches consist of
occasional spill flows over the dam, seepage flows, and accretion from tributary streams.
Catawba River Bypassed Reach: This stream section (5.9 miles long) flows from the
Catawba Dam of Lake James to its confluence with the Linville River below the
9

NC 401 Water Quality Certification Application
Bridgewater Powerhouse. It is host to warm -water aquatic species including sunfish and
mussels. Flow in this section will be significantly enhanced via continuous minimum flow
releases, including flow releases during drought conditions.
Paddy Creels Bypassed Reach: This creels (0.7 mile long) flows from the Paddy Creels
Dam at Lake James into the Catawba River Bypassed Reach. Stakeholders toured the
Catawba River and Paddy Creek bypassed reaches and observed that the Paddy Creek
channel has been severely impacted by high tropical storm spill flows to the point that the
potential for significant aquatic habitat restoration is low. The Aquatic Resource
Committee agreed to a) not invest in the high implementation cost required to deliver flow
into this creek for a speculative gain, b) instead focus on maximizing habitat in the higher
priority Catawba River Bypassed Reach and the river below the Bridgewater Powerhouse,
and c) fully mitigate for the aquatic habitat not realized in Paddy Creek.
Mountain Island Bypassed Reach: This bypass (03 mile long) is unique in that a large
colony of a federally listed endangered species, the Schweinitz's sunflower, has become
established in the bypass channel. The current habitat in this location supports this species.
Due to the short length of this bypass and in order to not alter the habitat supporting this
sunflower species, stakeholders agreed to not introduce higher flow releases and to fully
mitigate for the aquatic habitat not realized in the Mountain Island Bypassed Reach.
Refer to Section 6 of the Supplemental Information Package for more details about the
development of the proposed mitigation package.
The Low Inflow Protocol (LIP) provides trigger points and procedures for how the
Catawba - Wateree Project will be operated by Duke, as well as water withdrawal reduction
measures and goals for other water users during periods of low inflow (i.e., periods when
there is not enough water flowing into the Project reservoirs to meet the normal water
demands while maintaining Remaining Usable Storage in the reservoir system at or above a
seasonal target level). A component of the LIP is critical flows. Critical flows are the
minimum flow releases from the hydro developments that may be necessary to:
10

NC 401 Water Quality Certification Application
1. Prevent long -term or irreversible damage to aquatic communities consistent with the
resource management goals and objectives for the affected stream reaches;
2. Provide some basic level of operability for Large Water Intakes located on the
affected stream reaches; and
3. Provide some basic level of water quality maintenance in the affected stream reaches.
Per the LIP, critical flows of 25 cfs will be provided to the Catawba River Bypassed Reach
once Stage 3 of the Low Inflow Condition is triggered. The Paddy Creek and Mountain
Island bypassed reach flows will be provided by leakage flows and accretion.
(d) MEASURES PLANNED OR TAKEN TO MAINTAIN DOWNSTREAM
WATER QUALITY SUCH AS ADEQUATE DISSOLVED OXYGEN.
It is important to note that there are currently no water quality requirements for the
Catawba - Wateree Project. Because the Project was originally licensed in 1958, prior to the
implementation of the federal Clean Water Act, the Project has never been required to
obtain a Section 401 Water Quality Certification. Consequently, there are no water quality
provisions in the current (soon to expire) license. ]However, Duke has monitored water
quality within the Project and has taken voluntary measures to allow the enhancement of
water quality (i.e., dissolved oxygen) during major equipment replacement outages.
Measures Already Taken
Because historical dissolved oxygen (DO) conditions from many of the Catawba - Wateree
Project releases were at times lower than the DO standard established by North and South
Carolina, Duke, as part of the station upgrades and hydro runner replacements, evaluated
and installed various turbine venting modifications at some stations (summarized below) to
boost dissolved oxygen concentrations in the downstream reaches.
11

NC 401 Water Quality Certification Application
Table 3. Locations and descriptions of current measures for enhancing dissolved oxygen for the
Catawba - Wateree Hydroelectric Developments in North Carolina.
Development
Existing Turbine Venting
Bridgewater
Enhanced Vacuum Breaker (Units 1 & 2)
Rhodhiss
Hollow Stay Vanes (Units 1 & 2)
Original Vacuum Breaker (Unit 3)
Oxford
Hub Venting Ruiner (Units 1 & 2)
Lookout Shoals
Original Vacuum Breaker (Units 1
Cowans Ford
N/A (Kaplan Ruiner)
Mountain Island
Hollow Stav Vanes (Units 1 — 4)
Turbine venting utilizes existing low pressure areas within the scroll case, turbine, or draft
tube which, if vented to the atmosphere, would draw air into the flowing water. Vacuum
breakers, i.e. small air valves opened routinely to equalize the air pressures at the beginning
and end of a generation cycle, allow minimal air flow into the hub or cone of a Francis
turbine. Hub venting enhances the air flow by replacing the vacuum breakers with either
more and /or larger air induction ports which are opened during electric generation to allow
air to flow into the low pressure area at the hub or cone of the turbine. Stay vane venting
(stay vanes are metal, sometimes hollow, plates that direct water into the turbine)
modifications allow air to flow from specially constricted air induction ports into the
hollow portion of the plates and into the water at the low pressure, trailing edge of the stay
vanes. Auto venting is a relatively recent innovation which, in addition to utilizing other
low pressure areas for air induction, employs uniquely constricted, hollow turbine blades
for air introduction.
Please refer to Table 4 for additional measures proposed by Duke to meet minimum flow
release and /or DO requirements. This is also Appendix L of the CRA - Flow and Water
Quality Implementation Plan.
Additional information is also available in the following sections of the CRA:
■ Section 4.5: North Carolina Flow Mitigation Package
■ Section 6.0: Low Inflow Protocol Agreements
■ Appendix A- Section A -3: Low Inflow Protocol Article
■ Appendix C: Low Inflow Protocol (LIP) for the Catawba - Wateree Project
12

NC 401 Water Quality Certification Application
■ Appendix A- Section 2.0: Minimum Flows, Wylie High Inflow Protocol, Flows
Supporting Public Water Supply and Industrial Processes, and Flow and Water Quality
Implementation Plan
Quality Assurance Project Plan (QAPP)
Appendix A of the accompanying Supplemental Information Package presents a detailed
description of the QAPP that is proposed for the Catawba - Wateree Project.
13

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011

NC 401 Water Quality Certification Application
11. WHAT IS THE SIZE OF THE WATERSHED?
Table 5. Catawba- Wateree river basin drainage area.
Impoundment
Individual Drainage Basin
(s q. mi.)
Cumulative Drainage Area
(s q. mi.)
Lake James
380
380
Lake Rhodhiss
710
1,090
Lake Hickory-
220
1,310
Lookout Shoals Lake
140
1,450
Lake Norman
340
1,790
Mountain Island Lake
70
1,860
Lake Wylie
1,160
3,020
Drainage Area Within North Carolina
(Including the South Carolina portion of the Lake Wylie
Drainage Area)
3,020
WHAT IS THE FULL -POND SURFACE AREA?
Table 6. Catawba - Wateree impoundment surface areas.
Impoundment
Full -Pond Surface Area
(ac)
Lake James
6,754
Lake Rhodhiss
2,724
Lake Hickory-
4,072
Lookout Shoals Lake
1,155
Lake Norman
32,339
Mountain Island Lake
3,117
Lake Wylie (total)
12,177
Total Impoundment Surface Areas
(Including all of Lake Wylie)
62,338
12. YOU ARE REQUIRED TO CONTACT THE US FISH AND WILDLIFE SERVICE
AND /OR NATIONAL MARINE FISHERIES SERVICE REGARDING THE
PRESENCE OF ANY FEDERALLY LISTED OR PROPOSED FOR LISTING
ENDANGERED OR THREATENED SPECIES OR CRITICAL HABITAT IN THE
PERMIT AREA THAT MAY BE AFFECTED BY THE PROPOSED PROJECT.
DATE CONTACTED:
Letter from Roger L. Banks ( USFWS - Field Supervisor) and David H. Racldey (NOAA
Fisheries - Charleston Area Office Chief), received on May 30, 2003, in association with
Project ESA Section 7 consultation request (February 7, 2003) and subsequent
letters /discussions with the USFWS throughout the relicensing stakeholder process. This
letter served as a combined response from both the Asheville, NC, and Charleston, SC,
FWS Field Offices and NOAA Fisheries, and addressed Section 7 concerns in both states.
20

NC 401 Water Quality Certification Application
Refer also to Section 7.1.2 and Appendix E of the accompanying Supplemental
Information Package.
13. YOU ARE REQUIRED TO CONTACT THE STATE HISTORIC PRESERVATION
OFFICER (SHPO) REGARDING THE PRESENCE OF HISTORIC PROPERTIES
IN THE PERMIT AREA WHICH MAY BE AFFECTED BY THE PROPOSED
PROJECT. DATE CONTACTED:
Letter from Jennifer R. Huff (Duke Energy - Hydro Licensing and Compliance), sent
November 17, 2004 to Renee Gledhill- Earley (North Carolina Department of Cultural
Resources - State Historic Preservation Officer) in regards to the Catawba - Wateree Project
Relicensing, Cultural Resources Draft Study Report, and soliciting comments and
questions. Additional letters /discussions with the SHPO throughout the relicensing
stakeholder process are available in the Application for New License. A letter dated April
16, 2008 from Peter Sandbeck, State Historic Preservation Office of the North Carolina
Department of Cultural Resources provides a formal response to the acceptability of the
Historic Properties Management Plan associated with the Application for New License.
14. DOES THE PROJECT INVOLVE AN EXPENDITURE OF PUBLIC FUNDS OR
THE USE OF PUBLIC (STATE) LAND? NO
(IF NO, GO TO 15)
(a) IF YES, DOES THE PROJECT REQUIRE PREPARATION OF AN
ENVIRONMENTAL DOCUMENT PURSUANT TO THE REQUIREMENTS
OF THE NORTH CAROLINA ENVIRONMENTAL POLICY ACT? YES ❑
NO ❑
(b) IF YES, HAS THE DOCUMENT BEEN REVIEWED THROUGH THE
NORTH CAROLINA DEPARTMENT OF ADMINISTRATION STATE
CLEARINGHOUSE YES ❑ NO ❑
IF ANSWER 14b IS YES, THEN SUBMIT APPROPRIATE DOCUMENTATION
FROM THE STATE CLEARINGHOUSE WITH THE NORTH CAROLINA
ENVIRONMENTAL POLICY ACT. QUESTIONS REGARDING THE STATE
CLEARINGHOUSE REVIEW PROCESS
21

NC 401 Water Quality Certification Application
SHOULD BE DIRECTED TO MS. CHRYS BAGGETT, DIRECTOR STATE
CLEARINGHOUSE, NORTH CAROLINA DEPARTMENT OF
ADMINISTRATION, 116 WEST JONES STREET, RALEIGH, NORTH
CAROLINA 27603 -8003, TELEPHONE [phone].
15. THE FOLLOWING ITEMS SHOULD BE INCLUDED WITH THIS
APPLICATION IF PROPOSED ACTIVITY INVOLVES THE DISCHARGE OF
EXCAVATED OF FILL MATERIAL INTO WETLANDS: Not Applicable
(a) WETLAND DELINEATION MAP SHOWING ALL WETLANDS, STREAMS,
LAKES, AND PONDS ON THE PROPERTY (FOR NATIONWIDE PERMIT
NUMBERS 14, 18, 21, 26, 29, AND 38). ALL STREAM (INTERMITTENT AND
PERMANENT) ON THE PROPERTY MUST BE SHOWN ON THE MAP.
MAP SCALES SHOULD BE 1 INCH EQUALS 50 FEET OF 1 INCH EQUALS
100 FEET OF THEIR EQUIVALENT.
(b) IF AVAILABLE, REPRESENTATIVE PHOTOGRAPH OF WETLANDS TO
BE IMPACTED BY PROJECT.
(c) IF DELINEATION WAS PERFORMED BY A CONSULTANT, INCLUDE
ALL DATA SHEETS RELEVANT TO THE PLACEMENT OF THE
DELINEATION LINE.
(d) ATTACH A COPY OF THE STORMWATER MANAGEMENT PLAN IF
REQUIRED.
(e) WHAT IS LAND USE OF SURROUNDING PROPERTY?
(f) IF APPLICABLE, WHAT IS PROPOSED METHOD OF SEWAGE DISPOSAL?
16. CERTIFICATION FEE
(a) IF THE IMPACT IS LESS THAN 1 ACRE OF WETLAND OR WATER AND
LESS THAN 150 FEET OF STREAM, PLEASE ENCLOSE A CHECK FOR
$240.00 MADE OUT TO THE NORTH CAROLINA DIVISION OF WATER
QUALITY.
22

NC 401 Water Quality Certification Application
(b) IF THE IMPACT EXCEEDS EITHER OR BOTH OF THE LEVELS IN (a),
PLEASE ENCLOSE A CHECK FOR $570.00 MADE OUT TO THE NORTH
CAROLINA DIVISION OF WATER QUALITY.
17. PUBLIC NOTICE IS REQUIRED FOR ALL FERC PROJECTS. PLEASE NOTE
THAT THE APPLICANT IS REQUIRED TO REIMBURSE THE DIVISION OF
WATER QUALITY FOR THE COSTS ASSOCIATED WITH THE PLACEMENT
OF THE PUBLIC NOTICE. REFERENCE 15A NCAC 211.0503 (f).
SIGNED AND DATED AGENT AUTHORIZATION LETTER, IF APPLICABLE.
NOTE: WETLANDS OR WATERS OF THE US MAY NOT BE IMPACTED PRIOR TO:
1. ISSUANCE OF A SECTION 404 CORPS OF ENGINEERS PERMIT,
2. EITHER THE ISSUANCE OR WAIVER OF A 401 DIVISION OF WATER
QUALITY CERTIFICATION, AND
3. (IN THE TWENTY COASTAL COUNTIES ONLY), A LETTER FROM
THE NORTH CAROLINA DIVISION OF COASTAL MANAGEMENT
STATING THE PROPOSED ACTIVITY IS CONSISTENT WITH THE
NORTH CAROLINA COASTAL MANAGEMENT PROGRAM.
OWNER'S /AGENT'S SIGNATURE
Steven D. Jester, Vice President
Hydro Licensing and Lake Services
Duke Energy Carolinas, LLC
6z *0
DATE
(AGENT'S SIGNATURE VALID ONLY IF AUTHORIZATION LETTER FROM
THE OWNER IS PROVIDED).
23

NORTH CAROLINA 401 WATER QUALITY CERTIFICATION
SUPPLEMENTAL INFORMATION PACKAGE
24

CATAWBA - WATEREE HYDROELECTRIC PROJECT
(FERC No. 2232)
NORTH CAROLINA 401 WATER QUALITY CERTIFICATION APPLICATION
SUPPLEMENTAL INFORMATION PACKAGE
TABLE OF CONTENTS
Section Title Page No.
SECTION I
INTRODUCTION .......................................................... ............................... I
SECTION 2
CATAWBA- WATEREE PROJECT DESCRIPTION ............. ..............................2
SECTION 3
OVERVIEW OF THE CATAWBA- WATEREE RELICENSING PROCESS .............
5
3.1
The Regulatory Track ..................................................................... ..............................5
3.2
The Stakeholder Agreement Track ................................................. ..............................7
3.3
How Stakeholder Teams Balanced Water Needs ........................... ..............................9
3.4
Benefits of the Comprehensive Relicensing Agreement .............. ..............................1
I
3.5
Applicable Sections of the CRA .................................................... .............................14
SECTION 4
WATER QUALITY ASSESSMENT PROCESS ................... .............................15
4.1
Existing Aquatic Resources and Uses ........................................... .............................15
4.2
Discrete Bubble Model Analysis of Proposed Aeration Modifications .....................18
4.2.1 Assessment of Tailrace Water Quality .............................. .............................19
4.2.2 Initial Turbine Tests ........................................................... .............................20
4.2.3 Discrete Bubble Model — Field Testing and Calibration ... .............................22
4.2.4 Discrete Bubble Model — Aeration Curves for Each Unit . .............................27
4.2.5 Application of the Discrete Bubble Model to Hourly Historical Data...........30
4.2.6 Conservative Assumptions of Applying the Dynamic Bubble Model to
Predict Future Compliance with Water Quality Standards .............................34
4.3
Assessment of Operating Scenarios ............................................... .............................36
4.4
Quality Assurance Project Plan ..................................................... .............................37
SECTION 5
WATER QUALITY ASSESSMENT AND IMPROVEMENTS — INDIVIDUAL
DEVELOPMENTS................................................................... .............................38
5.1
Bridgewater Development ............................................................. .............................38
5.1.1 Current Status .................................................................... .............................38
5.1.1.1 North Carolina DWQ Assessments and Water Quality Standards .3
8
5.1.1.2 FERC Relicensing Data Summary ...................... .............................40
i

TABLE OF CONTENTS
(Continued)
Section Title Pate No.
5.1.2
Water Quality Issue Identification and Evaluation ............ .............................47
5. 1.3
Project Modifications for Water Quality Compliance and Resource
Enhancement...................................................................... .............................48
5.1.4
Reasonable Assurance of Future Compliance and Resource
Enhancement.................................................................... ...............................
52
5.1.4.1 Water Quality Compliance - Numeric Standards .............................52
5.1.4.2 Resource Enhancement - Existing Use Standards ............................53
5.1.5
Evaluation of Potential Reservoir Impacts Resulting From Altering
HistoricFlows .................................................................... .............................57
5.2 Rhodhiss Development .................................................................. .............................57
5.2.1
Current Status .................................................................... .............................57
5.2.1.1 North Carolina DWQ Assessments and Water Quality Standards
..57
5.2.1.2 FERC Relicensing Data Summary ...................... .............................60
5.2.2
Water Quality Issue Identification and Evaluation ............ .............................62
5.2.3
Project Modifications for Water Quality Compliance and Resource
Enhancement.................................................................... ...............................
63
5.2.4
Reasonable Assurance of Future Compliance and Resource
Enhancement.................................................................... ...............................
64
5.2.4.1 Dissolved Oxygen - Numeric Standards ............. .............................64
5.2.4.2 Resource Enhancement - Existing Use Standards ............................69
5.2.5
Evaluation of Potential Reservoir Impacts Resulting from Altering
HistoricFlows .................................................................... .............................70
5.3 Oxford Development ..................................................................... .............................70
5.3.1
Current Status .................................................................... .............................72
53.1.1 North Carolina DWQ Assessments and Water Quality Standards
..72
5.3.1.2 FERC Relicensing Data Summary ...................... .............................73
5.3.2
Water Quality Issue Identification and Evaluation ............ .............................77
5.3.3
Project Modifications for Water Quality Compliance and Resource
Enhancement.................................................................... ...............................
77
5.3.4
Reasonable Assurance of Future Compliance and Resource
Enhancement.................................................................... ...............................
80
53.4.1 Dissolved Oxygen - Numeric Standards ............. .............................80
5.3.4.2 Resource Enhancement - Existing Use Standards ............................84
ii

TABLE OF CONTENTS
(Continued)
Section Title Pate No.
5.3.5
Evaluation of Potential Reservoir Impacts Resulting from Altering
HistoricFlows .................................................................... .............................87
5.4 Lookout Shoals Development ........................................................ .............................87
5.4.1
Current Status .................................................................... .............................87
5.4.1.1 North Carolina DWQ Assessments and Water Quality Standards
..87
5.4.1.2 FERC Relicensing Data Summary ...................... .............................90
5.4.2
Water Quality Issue Identification and Evaluation ............ .............................92
5.4.3
Project Modifications for Water Quality Compliance and Resource
Enhancement.................................................................... ...............................
92
5.4.4
Reasonable Assurance of Future Compliance and Resource
Enhancement.................................................................... ...............................
94
5.4.4.1 Dissolved Oxygen - Numeric Standards ............. .............................94
5.4.4.2 Resource Enhancement - Existing Use Standards ............................99
5.4.5
Evaluation of Potential Reservoir Impacts Resulting from Altering
HistoricFlows .................................... ............................... ............................100
5.5 Cowans Ford Development ........................... ............................... ............................101
5.5.1
Current Status .................................... ............................... ............................101
5.5.1.1 North Carolina DWQ Assessments and Water Quality Standards
101
5.5.1.2 FERC Relicensing Data Summary ..................... ............................103
5.5.2
Water Quality Issue Identification and Evaluation ........... ............................106
5.5.3
Project Modifications for Water Quality Compliance and Resource
Enhancement...................................... ............................... ............................106
5.5.4
Reasonable Assurance of Future Compliance and Resource
Enhancement...................................... ............................... ............................107
5.5.4.1 Dissolved Oxygen - Numeric Standards ............ ............................107
5.5.4.2 Resource Enhancement - Existing Use Standards ..........................114
5.5.5
Evaluation of Potential Reservoir Impacts Resulting from Altering
HistoricFlows .................................... ............................... ............................115
5.6 Mountain Island Development ...................... ............................... ............................115
5.6.1
Current Status .................................... ............................... ............................117
5.6.1.1 North Carolina DWQ Assessments and Water Quality Standards
117
5.6.1.2 FERC Relicensing Data Summary ..................... ............................118
iii

TABLE OF CONTENTS
(Continued)
Section Title Pate No.
5.6.2 Water Quality Issue Identification and Evaluation ........... ............................129
5.6.3 Project Modifications for Water Quality Compliance and Resource
Enhancement.................................................................... .............................13
0
5.6.4 Reasonable Assurance of Future Compliance and Resource
Enhancement.................................................................... .............................13
2
5.6.4.1 Dissolved Oxygen - Numeric Standards ............ ............................132
5.6.4.2 Resource Enhancement - Existing Use Standards ..........................136
5.6.5 Evaluation of Potential Reservoir Impacts Resulting from Altering
HistoricFlows .................................... ............................... ............................138
5.7 Wylie Development in North Carolina .......... ............................... ............................138
5.7.1 North Carolina DWQ Assessments and Water Quality Standards ...............138
SECTION 6 FLOW MITIGATION PACKAGE .... ............................... ............................140
SECTION 7 SUSTAINABILITY OF THE CRA ... ............................... ............................148
7.1 Additional Features of the CRA .................... ............................... ............................148
7. 1.1 Water Quality Management ............... ............................... ............................148
7.1.2 Resource Management ....................... ............................... ............................150
7. 1.3 Water Quantity Management ............. ............................... ............................151
7.2 Assessments of Operational Scenarios .......... ............................... ............................152
SECTION 8 SUMMARY AND CONCLUSIONS ... ............................... ............................157
SECTION 9 REFERENCES .............................. ............................... ............................164
APPENDICES
APPENDIX A - QUALITY ASSURANCE PROJECT PLAN
APPENDIX B - APPLICATION OF THE DISCRETE BUBBLE MODEL TO TURBINE
AERATION ASSESSMENTS FOR THE CATAWBA - WATEREE PROJECT
APPENDIX C - TURBINE AERATION ASSESSMENT FOR WYLIE HYDRO — 2002
APPENDIX D - REFERENCED CORRESPONDENCE
1V

CATAWBA - WATEREE HYDROELECTRIC PROJECT
(FERC No. 2232)
NORTH CAROLINA 401 WATER QUALITY CERTIFICATION APPLICATION
SUPPLEMENTAL INFORMATION PACKAGE
LIST OF FIGURES
Figure Title Page No.
FIGURE 1
CATAWBA - WATEREE PROJECT (FERC NO. 2232) ........... ..............................3
FIGURE 2
CHEOPS MODEL USED INPUT FROM VARIOUS STUDIES TO
EVALUATE POTENTIAL PROJECT OPERATING SCENARIOS ..................10
FIGURE 3
DISCRETE BUBBLE MODEL APPLICATION AND CALIBRATION
FOR THE CATAWBA - WATEREE PROJECT ...................... .............................18
FIGURE 4
RESULTS OF TURBINE VENTING TESTS PRIOR TO 2006 ..........................21
FIGURE 5
PRELIMINARY DATA ASSESSMENT OF RHODHISS DEVELOPMENT
TURBINE VENTING TEST FOR DISCRETE BUBBLE MODEL ....................24
FIGURE 6
CALIBRATED BUBBLE SIZE WITH PROJECT FLOW ..... .............................25
FIGURE 7
COMPARISON OF MEASURED DISSOLVED OXYGENTO DISCRETE
BUBBLE MODEL - PREDICTED DO ..................................... .............................26
FIGURE 8
AERATION CAPABILITY OF THE THREE UNIT TYPES AT THE
RHODHISS DEVELOPMENT UNDER ONE -UNIT OPERATION ..................27
FIGURE 9
AERATION CAPABILITY OF THE THREE UNIT TYPES AT THE
RHODHISS DEVELOPMENT UNDER TWO -UNIT OPERATION ..................28
FIGURE 10
AERATION CAPABILITY OF THE THREE UNIT TYPES AT THE
RHODHISS DEVELOPMENT UNDER THREE -UNIT OPERATION ..............29
FIGURE 11
FREQUENCY OF COMPLIANCE WITH STATE WATER QUALITY
STANDARDS FOR HOURLY DISSOLVED OXYGEN AT THE
RHODHISS DEVELOPMENT CALCULATED FROM THE DISCRETE
BUBBLE MODEL AND COMPARED TO THE HISTORICAL RECORD.......
33
FIGURE 12
BRIDGEWATER DEVELOPMENT ....................................... .............................39
FIGURE 13
RHODHISS DEVELOPMENT ................................................ .............................58
FIGURE 14
FREQUENCY OF COMPLIANCE WITH INSTANTANEOUS
DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (4.0
MG/L) FOR HOURLY DISSOLVED OXYGEN CONCENTRATIONS AT
RHODHISS CALCULATED FROM DISCRETE BUBBLE MODEL IN
COMPARISON TO THE HISTORICAL RECORD ............... .............................66
FIGURE 15
COMPARISON OF HOURS OF NON - COMPLIANCE AT RHODHISS TO
INSTANTANEOUS DISSOLVED OXYGEN STATE WATER QUALITY
STANDARDS (4.0 MG /L) CALCULATED FROM DISCRETE BUBBLE
MODEL AND THE HISTORICAL RECORD ........................ .............................67
v

LIST OF FIGURES
(Continued)
Figure Title Page No.
FIGURE 16 FREQUENCY OF COMPLIANCE WITH DAILY AVERAGE
vi
DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (5.0
MG /L) FOR DAILY AVERAGE DISSOLVED OXYGEN
CONCENTRATIONS AT RHODHISS CALCULATED FROM DISCRETE
BUBBLE MODEL IN COMPARISON TO THE HISTORICAL RECORD .......68
FIGURE 17
COMPARISON OF DAYS OF NON - COMPLIANCE AT RHODHISS TO
DAILY AVERAGE DISSOLVED OXYGEN STATE WATER QUALITY
STANDARDS (5.0 MG /L) CALCULATED FROM DISCRETE BUBBLE
MODEL AND THE HISTORICAL RECORD ........................ .............................69
FIGURE 18
OXFORD DEVELOPMENT .................................................... .............................71
FIGURE 19
FREQUENCY OF COMPLIANCE WITH INSTANTANEOUS
DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (4.0
MG/L) FOR HOURLY DISSOLVED OXYGEN CONCENTRATIONS AT
OXFORD CALCULATED FROM DISCRETE BUBBLE MODEL IN
COMPARISON TO THE HISTORICAL RECORD ............... .............................81
FIGURE 20
COMPARISON OF HOURS OF NON - COMPLIANCE WITH
INSTANTANEOUS DISSOLVED OXYGEN STATE WATER QUALITY
STANDARDS (4.0 MG /L) CALCULATED FROM DISCRETE BUBBLE
MODEL AND THE HISTORICAL RECORD ........................ .............................82
FIGURE 21
FREQUENCY OF COMPLIANCE WITH DAILY AVERAGE
DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (5.0
MG /L) FOR DAILY AVERAGE DISSOLVED OXYGEN
CONCENTRATIONS AT OXFORD CALCULATED FROM DISCRETE
BUBBLE MODEL IN COMPARISON TO THE HISTORICAL RECORD .......83
FIGURE 22
COMPARISON OF DAYS OF NON - COMPLIANCE AT OXFORD TO
DAILY AVERAGE DISSOLVED OXYGEN STATE WATER QUALITY
STANDARDS (5.0 MG /L) CALCULATED FROM DISCRETE BUBBLE
MODEL AND THE HISTORICAL RECORD ........................ .............................84
FIGURE 23
LOOKOUT SHOALS DEVELOPMENT ................................ .............................89
FIGURE 24
FREQUENCY OF COMPLIANCE WITH INSTANTANEOUS
DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (4.0
MG/L) FOR HOURLY DISSOLVED OXYGEN CONCENTRATIONS AT
LOOKOUT SHOALS CALCULATED FROM DISCRETE BUBBLE
MODEL IN COMPARISON TO THE HISTORICAL RECORD ........................
96
FIGURE 25
COMPARISON OF HOURS ON NON - COMPLIANCE AT LOOKOUT
SHOALS TO INSTANTANEOUS DISSOLVED OXYGEN STATE
WATER QUALITY STANDARDS (4.0 MG /L) FOR HOURLY
DISSOLVED OXYGEN CONCENTRATIONS CALCULATED FROM
DISCRETE BUBBLE MODEL AND THE HISTORICAL RECORD ................97
vi

LIST OF FIGURES
(Continued)
Figure Title Page No.
FIGURE 26 FREQUENCY OF COMPLIANCE WITH DAILY AVERAGE
DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (5.0
MG /L) FOR DAILY AVERAGE DISSOLVED OXYGEN
CONCENTRATIONS AT LOOKOUT SHOALS CALCULATED FROM
DISCRETE BUBBLE MODEL IN COMPARISON TO THE HISTORICAL
RECORD.................................................................................. .............................98
FIGURE 27 COMPARISON OF DAYS OF NON - COMPLIANCE AT LOOKOUT
SHOALS TO DAILY AVERAGE DISSOLVED OXYGEN STATE
WATER QUALITY STANDARDS (5.0 MG /L) CALCULATED FROM
DISCRETE BUBBLE MODEL AND THE HISTORICAL RECORD ................99
FIGURE 28 COWANS FORD DEVELOPMENT ....... ............................... ............................102
FIGURE 29 ILLUSTRATION OF SKIMMER WEIR AT COWANS FORD
DEVELOPMENT ..................................... ............................... ............................108
FIGURE 30 FREQUENCY OF COMPLIANCE WITH INSTANTANEOUS
DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (4.0
MG/L) FOR HOURLY DISSOLVED OXYGEN CONCENTRATIONS AT
COWANS FORD CALCULATED FROM DISCRETE BUBBLE MODEL
IN COMPARISON TO THE HISTORICAL RECORD ......... ............................110
FIGURE 31 COMPARISON OF HOURS OF NON - COMPLIANCE AT COWANS
FORD TO INSTANTANEOUS DISSOLVED OXYGEN STATE WATER
QUALITY STANDARDS (4.0 MG /L) FOR HOURLY DISSOLVED
OXYGEN CONCENTRATIONS CALCULATED FROM DISCRETE
BUBBLE MODEL AND THE HISTORICAL RECORD ...... ............................111
FIGURE 32 FREQUENCY OF COMPLIANCE WITH DAILY AVERAGE
DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (5.0
MG /L) FOR DAILY AVERAGE DISSOLVED OXYGEN
CONCENTRATIONS AT COWANS FORD CALCULATED FROM
DISCRETE BUBBLE MODEL IN COMPARISON TO THE HISTORICAL
RECORD.................................................. ............................... ............................112
FIGURE 33 COMPARISON OF DAYS OF NON - COMPLIANCE AT COWANS FORD
TO DAILY AVERAGE DISSOLVED OXYGEN STATE WATER
QUALITY STANDARDS (5.0 MG /L) CALCULATED FROM DISCRETE
BUBBLE MODEL AND THE HISTORICAL RECORD ...... ............................113
FIGURE 34 COMPARISON OF THE RANGE OF DISSOLVED OXYGEN ABOVE
THE SKIMMER WEIR IN THE FOREBAY OF COWANS FORD AND
COWANS FORD TAILRACE DISSOLVED OXYGEN — EVIDENCE OF
SENSORFOULING ................................. ............................... ............................114
FIGURE 35 MOUNTAIN ISLAND DEVELOPMENT .............................. ............................116
vii

LIST OF FIGURES
(Continued)
Figure Title Page No.
FIGURE 36 FREQUENCY OF COMPLIANCE WITH INSTANTANEOUS
DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (4.0
MG/L) FOR HOURLY DISSOLVED OXYGEN CONCENTRATIONS AT
MOUNTAIN ISLAND CALCULATED FROM DISCRETE BUBBLE
MODEL IN COMPARISON TO THE HISTORICAL RECORD ......................125
FIGURE 37 COMPARISON OF HOURS OF NON - COMPLIANCE AT MOUNTAIN
ISLAND TO INSTANTANEOUS DISSOLVED OXYGEN STATE
WATER QUALITY STANDARDS (4.0 MG /L) FOR HOURLY
DISSOLVED OXYGEN CONCENTRATIONS CALCULATED FROM
DISCRETE BUBBLE MODEL AND THE HISTORICAL RECORD ..............126
FIGURE 38 FREQUENCY OF COMPLIANCE WITH DAILY AVERAGE
viii
DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (5.0
MG /L) FOR DAILY AVERAGE DISSOLVED OXYGEN
CONCENTRATIONS AT MOUNTAIN ISLAND CALCULATED FROM
DISCRETE BUBBLE MODEL IN COMPARISON TO THE HISTORICAL
RECORD.................................................. ............................... ............................127
FIGURE 39
COMPARISON OF DAYS OF NON - COMPLIANCE AT MOUNTAIN
ISLAND TO DAILY AVERAGE DISSOLVED OXYGEN STATE WATER
QUALITY STANDARDS (5.0 MG /L) CALCULATED FROM DISCRETE
BUBBLE MODEL AND THE HISTORICAL RECORD ...... ............................128
FIGURE 40
EASEMENTS ON THE LINVILLE AND CATAWBA RIVERS AND
ASSOCIATED TRIBUTARIES USED FOR FLOW MITIGATION ................135
FIGURE 41
EASEMENTS ON THE CATAWBA RIVER IN THE BRIDGEWATER
REGULATED RIVER REACH USED FOR FLOW MITIGATION ................136
FIGURE 42
EASEMENTS ON THE CATAWBA RIVER AND ASSOCIATED
TRIBUTARIES IN THE BRIDGEWATER REGULATED RIVER REACH
USED FOR FLOW MITIGATION .......... ............................... ............................137
FIGURE 43
EASEMENTS ON THE JOHNS RIVER IN THE BRIDGEWATER
REGULATED RIVER REACH USED FOR FLOW MITIGATION ................138
FIGURE 44
EASEMENTS ON THE CATAWBA RIVER DOWNSTREAM OF THE
LOOKOUT SHOALS DEVELOPMENT USED FOR FLOW MITIGATION..
139
viii

CATAWBA - WATEREE HYDROELECTRIC PROJECT
(FERC No. 2232)
NORTH CAROLINA 401 WATER QUALITY CERTIFICATION APPLICATION
SUPPLEMENTAL INFORMATION PACKAGE
LIST OF TABLES
Table Title Page No.
TABLE 1 CATAWBA - WATEREE PROJECT — PHYSICAL DESCRIPTION OF
EACH DEVELOPMENT .......................................................... ..............................4
TABLE 2 STUDIES PREFORMED DURING THE CATAWBA - WATEREE
RELICENSING PROCESS ....................................................... ..............................6
TABLE 3 STUDIES RELATED TO THE AQUATIC RESOURCES OF THE
CATAWBA - WATEREE PROJECT ........................................ .............................16
TABLE 4 DISCRETE BUBBLE MODEL APPLICATION TO PREDICT FUTURE
STATION TAILRACE DISSOLVED OXYGEN: EXAMPLE OF FLOW
ALLOCATION TO THE RHODHISS DEVELOPMENT WHEN 2 UNITS
WERE OPERATING ................................................................ .............................31
TABLE 5 DISCRETE BUBBLE MODEL APPLICATION TO PREDICT FUTURE
STATION TAILRACE DISSOLVED OXYGEN: EXAMPLE OF FLOW
ALLOCATION TO THE RHODHISS DEVELOPMENT WHEN 3 UNITS
WERE OPERATING ................................................................ .............................32
TABLE 6 AVERAGE DISSOLVED OXYGENSENSOR FOULING RATES ....................35
TABLE 7 SUMMARY OF BRIDGEWATER DEVELOPMENT AERATION
CAPABILITIES........................................................................ .............................49
TABLE 8
TARGET RESERVOIR ELEVATIONS FOR LAKE JAMES ............................50
TABLE 9
CONTINUOUS MINIMUM HABITAT FLOWS (CFS) FOR THE
BRIDGEWATER DEVELOPMENT TAILWATER ............... .............................51
TABLE 10
CONTINUOUS MINIMUM HABITAT FLOWS (CFS) FOR THE
BRIDGEWATER DEVELOPMENT CATAWBA RIVER BYPASSED
REACH..................................................................................... .............................51
TABLE 11
PREDICTED HABITAT GAINS EXPRESSED AS PERCENTAGE OF
UNREGULATED INDEX C FLOWS AT THE BRIDGEWATER
DEVELOPMENT IN THE BRIDGEWATER REGULATED RIVER
REACH (DOWNSTREAM OF BRIDGEWATER POWERHOUSE AND
UPSTREAM OF THE CONFLUENCE OF THE CATAWBA RIVER)
RESULTING FROM PROPOSED CRA FLOWS* ................. .............................55
TABLE 12
PREDICTED HABITAT GAINS EXPRESSED AS PERCENTAGE OF
UNREGULATED INDEX C FLOWS AT THE BRIDGEWATER
DEVELOPMENT IN THE CATAWBA BYPASS REACH
(DOWNSTREAM OF MUDDY CREEK AND UPSTREAM OF THE
ix

LIST OF TABLES
(Continued)
Table Title Page No.
x
CONFLUENCE OF THE LINVILLE /CATAWBA REGULATED RIVER
REACH) RESULTING FROM PROPOSED CRA FLOWS* . .............................56
TABLE 13
SUMMARY OF RHODHISS DEVELOPMENT AERATION
CAPABILITIES........................................................................ .............................63
TABLE 14
TARGET RESERVOIR ELEVATIONS FOR LAKE RHODHISS .....................64
TABLE 15
SUMMARY OF OXFORD DEVELOPMENT AERATION CAPABILITIES
...78
TABLE 16
TARGET RESERVOIR ELEVATIONS FOR LAKE HICKORY .......................78
TABLE 17
CONTINUOUS MINIMUM HABITAT FLOWS (CFS) FOR THE
OXFORD DEVELOPMENT TAILWATER ........................... .............................79
TABLE 18
PREDICTED HABITAT GAINS EXPRESSED AS PERCENTAGE OF
UNREGULATED INDEX C FLOWS AT THE OXFORD DEVELOPMENT
IN THE CATAWBA REGULATED RIVER REACH RESULTING FROM
PROPOSED CRA FLOWS* .................................................... .............................86
TABLE 19
SUMMARY OF LOOKOUT SHOALS DEVELOPMENT AERATION
CAPABILITIES........................................................................ .............................93
TABLE 20
TARGET RESERVOIR ELEVATIONS FOR LOOKOUT SHOALS LAKE .....93
TABLE 21
CONTINUOUS MINIMUM HABITAT FLOWS (CFS) FOR THE
LOOKOUT SHOALS DEVELOPMENT TAILWATER ........ .............................94
TABLE 22
COWANS FORD DEVELOPMENT AERATION CAPABILITIES .................106
TABLE 23
TARGET RESERVOIR ELEVATIONS FOR LAKE NORMAN .....................107
TABLE 24
SUMMARY OF MOUNTAIN ISLAND DEVELOPMENT AERATION
CAPABILITIES........................................ ............................... ............................122
TABLE 25
TARGET RESERVOIR ELEVATIONS FOR MOUNTAIN ISLAND LAKE..
123
TABLE 26
FLOW MITIGATION NEEDS ................ ............................... ............................132
TABLE 27
MITIGATION RATIOS ........................... ............................... ............................133
TABLE 28
RIVER MITIGATION CREDIT CALCULATIONS ............. ............................134
TABLE 29
STREAM MITIGATION CREDIT CALCULATIONS ......... ............................134
TABLE 30
METRICS USED TO EVALUATE OVERALL WATER QUALITY
INFLUENCES RESULTING FROM THE CATAWBA - WATEREE
COMPREHENSIVE RELICENSING AGREEMENT ........... ............................146
x

Section I
Introduction
Duke Energy Carolinas, LLC (Duke) operates the Catawba - Wateree Hydroelectric Project
(Project), which is licensed as Federal Energy Regulatory Commission (FERC) Project No.
2232. Duke is required to obtain a new license (New License) to continue operating the Project.
The federal action of issuing a New License for the Project triggers the need for Duke to obtain a
water quality certification pursuant to Section 401 of the federal Clean Water Act. The
Application for New License was submitted to the FERC on August 29, 2006, along with a
Comprehensive Relicensing Agreement (CRA), signed by 70 stakeholder organizations and
individuals. The FERC has been reviewing the application and CRA since its submittal and, as
part of the process, issued a "Ready for Environmental Analysis" (REA) on April 7, 2008. The
issuance of the REA requires that Duke submit an application for water quality certification in
accordance with the requirements of the Federal Power Act within 60 days following the REA
notice (June 6, 2008).
By filing this application, Duke is seeking to obtain state certification in accordance with the
Clean Water Act Section 401. The subject of this certification is the continued operation of the
Project under a FERC - issued New License that is consistent with applicable sections of the
Catawba - Wateree CRA. Applicable sections are listed in Section 3.5 of this document. This
application is intended to provide the basis to certify that the operations of the Project under the
New License are consistent with applicable CRA provisions and provide reasonable assurance
that Duke will be able to meet applicable water quality standards in accordance with Section 401
of the Clean Water Act.
1

Section 2
Catawba - Wateree Project Description
The Catawba River begins in western North Carolina and flows easterly and southerly into South
Carolina, where it joins Big Wateree Creek to form the Wateree River. The Project is made up of
13 hydroelectric stations and 11 reservoirs on the Catawba and Wateree rivers. Reservoirs along
the Project include Lake James, Lake Rhodhiss, Lake Hickory, Lookout Shoals Lake, Lake
Norman, and Mountain Island Lake in North Carolina; and Lake Wylie, Fishing Creek
Reservoir, Great Falls Reservoir, Cedar Creek Reservoir, and Lake Wateree in South Carolina
(see Figure 1). Constriction of the Project's developments began in the early 1900s, with the
final development (Cowans Ford) completed in 1963.
The Project spans over 225 river miles, has a total drainage area of 4,750 square miles, and
encompasses approximately 1,795 miles of reservoir and island shoreline within nine counties in
North Carolina and five counties in South Carolina. The Project does not occupy any federal or
tribal lands. Table 1 below lists the physical aspects of each development.
2

Section 2 Catawba-Wateree Project Description
FIGURE I
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Section 3
Overview of the
Process
Catawba - Wateree Relicensing
The licensing process utilized by Duke is the FERC's Traditional Licensing Process (TLP-
Regulatory Track) supplemented with the development of a CRA (Stakeholder Agreement
Track). This approach has provided the required three -phase consultation process associated
with obtaining a new operating license along with the negotiation process that afforded federal,
state, and local government agencies as well as non - governmental stakeholders an active role in
the relicensing process. The goal has been to reach a mutually acceptable agreement that could
be incorporated into the requirements of the New License that represented all interests related to
the continued operation of the Project.
3.1 The Regulatory Track
The goal of the regulatory track was to execute the traditional three -phase consultation and study
process and complete all study reports so Duke could prepare and submit the license application
on time. The result was an innovative and progressive array of studies and other stakeholder
tools enveloping not only the 225 river miles including and lying between the Project reservoirs,
but also an additional 75 miles of the Wateree River from the Wateree Dam to its confluence
with the Congaree River.
The First Stage Consultation began in February 2003 when Duke filed its First Stage
Consultation Document with the FERC, thus formally initiating the relicensing process. Duke
filed its Notice of Intent with the FERC to relicense the Project on July 21, 2003.
The Second Stage Consultation (August 2003— August 2006) began with the development of
detailed study plans, included the actual field studies and development of study reports, and
concluded with the filing of the Application for New License with the FERC on August 29,
2006. All study plans, study reports, and resource committee reports were made available for
relicensing process participants to review. Relicensing process participants were invited to
5

Section 3 Oveiview of the Catawba- Wateree Relicensing Process
comment on reports and Study Teams and Resource Committees considered all comments
received. Table 2 lists the studies performed during the stage two consultation.
TABLE 2
STUDIES PREFORMED DURING THE CATAWBA - WATEREE
RELICENSING PROCESS
Aquatics 01
Fish Community Survey
and Assessment
Aquatics 02
Reservoir Fish Habitat
Assessment
Aquatics 03
Diadromous Fish Studies
Aquatics 04
Instream Flow Assessment
Aquatics 05
Fish Entrainment
Evaluation
Aquatics 06
Mussel Survey
Aquatics 07
Macrobenthic Survey
Ops 01
Hydrologic/Hydraulic
Operations Model
Ops 02
Reservoir Level Study
Ops 03
Trash Management Plan
Ops 04
Water Supply Study
Ops 05
Low Inflow Protocol Study
Ops 06
Maintenance and
Emergency Protocol
Ops 07
Recreation Flow
Communication Study
Ops 08
Wateree High Water Level
Management Study
Relicensing studies and computer
models provided relicensing
the impact of future operating
Cultural 01
Cultural 02
Cultural 03
Rec 01
Rec 02
SMP 01
SMP 02
Terrestrial 01
Terrestrial 02
Terrestrial 03
Terrestrial 04
Terrestrial 05
Terrestrial 06
Water Quality 01
Project Cultural Resources
Survey
Historic Properties
Management Plan
Mulberry Site Assessment
Recreation Use and Needs
Study
Recreation Flow Study
Shoreline Management
Plan Revision
Shoreline Management
Guidelines Revision
Wetlands Mapping and
Characterization
Floodplain Vegetation
Assessment
Great Falls Bypass
Botanical Study
RTE Species and Habitat
Survey
Breeding and Migratory
Bird Study
Great Falls Bypass VUldlife
Study
Water Quality of Reservoirs
and Riverine Reaches
Most studies were repeated at multiple locations on the Catawba- Wateree River
system. Several studies extended 75 miles beyond the most downstream hydro
development, Wateree, to the confluence of the Wateree and Congaree rivers.
The results of many of these studies have been used to determine compliance with the 401 Water
Quality Certification existing use standards. These study results are discussed in more detail in
Section 4 (Water Quality Assessment Process), Section 5 (Individual Developments), and
Section 8 (Summary and Conclusions) of this Supplemental Information Package (SIP).
6

Section 3 Oveiview of the Catawba- Wateree Relicensing Process
The Third Stage Consultation Phase (September 2006 — Issuance of New License) began with the
filing of the Application for New License with the FERC. The FERC leads this last stage, which
includes conducting an independent environmental analysis, establishing conditions to be
included in the New License, and concludes with the issuance of the New License.
3.2 The Stakeholder Agreement Track
The CRA is a formal and binding contract among the signing Parties that presents stakeholders'
recommendations to FERC for the New License. This is a result of extensive collaboration and
negotiations among approximately 80 organizations from both North and South Carolina,
producing an equitable, sustainable, long -term, and balanced agreement for the future operations
of the Project. The CRA includes both proposed license articles to be included in the New
License and other agreements not intended to be included in the New License. Those
agreements not included in the New License will be enforceable under state contract law.
The following organizations and individuals have signed and support the CRA
7

Section 3 Oveiview of the Catawba- Wateree Relicensing Process
Duke Energy Carolinas, LLC
Duke Energy Corporation
Abitibi Bowater
Alexander County, NC
American Whitewater
Area II Soil & Water Conservation Districts
Burke County, NC
Caldwell County, NC
Carolina Canoe Club
Catawba County, NC
Catawba Indian Nation
Catawba Indian Nation Tribal Historic
Preservation Office
Catawba Lands Conservancy
Catawba Regional Council of Governments
Catawba Valley Heritage Alliance
Catawba - Wateree Relicensing Coalition
Centralina Council of Governments
Chester Metropolitan District
City of Belmont, NC
City of Camden, SC
City of Charlotte, NC
City of Gastonia, NC
City of Hickory, NC
City of Morganton, NC
City of Mount Holly, NC
City of Rock Hill, SC
Crescent Resources, LLC
Foothills Conservancy
Gaston County, NC
Great Falls Hometown Association
Harbortowne Marina
International Paper
Iredell County, NC
Kershaw County, SC
Kershaw County Conservation District
Lake James Homeowners
Lake Wateree Association
Lake Wylie Marine Commission
Lancaster County Water & Sewer District
Lincoln County, NC
9
Lugoff -Elgin Water Authority
McDowell County, NC
Mecklenburg County, NC
Mountain Island Lake Association
Mountain Island Lake Marine Commission
North Carolina Dept. of Environment and
Natural Resources with its Divisions of
Forest Resources, Parks and Recreation,
Water Quality, and Water Resources
North Carolina Wildlife Federation
North Carolina Wildlife Resources
Commission
R & N Marina
South Carolina Dept. of Archives and
History
South Carolina Dept. of Natural Resources
South Carolina Dept. of Parks, Recreation
and Tourism
South Carolina Electric & Gas
South Carolina Wildlife Federation
Springs Global US, Inc.
Town of Davidson, NC
Town of Great Falls, SC
Town of Valdese, NC
Trout Unlimited, Inc.
Union County, NC
Wateree Homeowners Association —
Fairfield County
Western Piedmont Council of Governments
York County, SC
York County Culture & Heritage
Commission
William B. Cash
Shirley M. Greene
Frank J. Hawkins
Timothy D. Mead
Merlin F. Perry
Joseph W. Zdenek

Section 3 Oveiview of the Catawba- Wateree Relicensing Process
3.3 How Stakeholder Teams Balanced Water Needs
The results of several studies had to converge in order to equitably utilize the available water
supply in the Catawba - Wateree River Basin for all water -based interests (see Figure 2). The
CHEOPS model was developed to evaluate operations of all developments simultaneously under
various operating scenarios, and provide stakeholders with information on how well or poorly
any particular scenario met their individual and collective interests related to water quantity.
Input to the CHEOPS model came from the following studies:
■ Low Inflow Protocol (LIP) Study (drought management study)
■ Water withdrawal and return projections and water withdrawal intake elevations from the
Water Supply Study
■ Critical reservoir elevations from the Reservoir Level Study
■ Recreation flow levels and schedules from the Recreation Flow Study
■ Minimum continuous aquatic habitat flows from the In- stream Flow Study
■ Critical flows necessary for aquatic life and for downstream dischargers and withdrawers
■ Hydro unit performance, reservoir storage, sedimentation projections, and 51 -year inflow
history provided by Duke
Output from the CHEOPS model was provided in a stakeholder- specified format called a
Performance Measures Spreadsheet, which numerically and graphically enabled stakeholders to
determine if their water quantity -based interests were being met by a given operating scenario.
Other performance criteria that must be satisfied for each CHEOPS scenario run included:
■ Avoid entering LIP Stage 4 (Emergency Water Use Stage)
■ Do not uncover any reservoir located water intake.
■ Maintain downstream uses and critical flow needs (aquatic, municipal, and industrial).
9

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Section 3 Oveiview of the Catawba- Wateree Relicensing Process
Once a successful operating scenario was identified, several water quality metrics of that
scenario were compared to current -day operations. Factors including nutrient concentration,
reservoir DO, reservoir temperature, and reservoir fish habitat were shown either to be
unaffected or improved slightly during normal conditions under the operating proposal in the
CRA.
Participants on the stakeholder teams used these and other tools to understand how their
individual interests affected one another, test whether their proposals could be sustained by the
amount of water in the system, and validate the resilience of their proposals in the face of
increasing future water demands and severe drought periods.
3.4 Benefits of the Comprehensive Relicensing Agreement
The consensus recommendations of the 70 signatory stakeholder organizations and individuals
will improve, balance, and help sustain future power and non -power uses of the Project. The
CRA achieves an impressive balance among competing water uses and needs while improving
water quality in the Catawba - Wateree River Basin.
In this 401 certification SIP, these CRA provisions addressing water needs and existing uses are
supplemented with the modeling of proposed equipment modifications necessary to meet
applicable numeric water quality standards. Ten years of DO monitoring data were analyzed
under new CRA flow and reservoir conditions. This resulting application provides the basis to
certify that the operations of the Project under a New License with the proposed applicable CRA
provisions and water quality modifications will enable Duke to meet applicable existing use and
numeric standards requirements in accordance with Section 401 of the Clean Water Act.
The CRA also includes administrative provisions relative to the water quality certification and
FERC processes. The following administrative provisions have been excerpted from the CRA
(refer to the CRA for exact language):
11

Section 3 Oveiview of the Catawba- Wateree Relicensing Process
■ All Parties agree that Duke shall include the Flow and Water Quality Implementation Plan
( FWQIP) (see Table 4 in the NC 401 Water Quality Application and CRA Appendix L),
and the Water Quality Monitoring Plan (WQMP) (see CRA Appendix F) with its
applications for 401 Water Quality Certifications as recommended plans for the Project.
All Parties, except the North Carolina Department of Environment and Natural Resources
(NCDENR), agree that the FWQIP shall be recommended to be a condition of the 401
Water Quality Certifications.
■ After a New License is received, Duke will file the FWQIP and the WQMP with the FERC
for approval. This filing will include the FWQIP and WQMP that have been certified by
the state water quality agencies along with any engineering and constriction details
determined to be needed. The Parties acknowledge that, except for the replacement of the
Bridgewater Powerhouse, Duke shall not begin implementation of the FWQIP or the
WQMP until the FERC has approved these plans.
■ Duke will initiate interim changes to current operation at selected Project developments
that require physical equipment additions or modifications in accordance with the FWQIP.
Duke shall initiate the Interim Measures for Providing Aquatic Flow and /or DO
Enhancement until physical modifications are complete as identified in the FWQIP within
60 days following the issuance of the New License. The interim measures will continue at
each dam or powerhouse until completion of the permanent modification.
■ Unless operating in accordance with the LIP and /or the Maintenance and Emergency
Protocol, Duke shall operate the hydro units at the powerhouses identified for Interim
Measures in the FWQIP in the following manner:
— When Duke is providing flow releases, reservoir level control, and /or generation
with any of these powerhouses at times that DO in the flow release is below 401
Water Quality standards, Duke will operate the available hydro units with the
greatest existing DO enhancement capability in a first -on, last -off hierarchy. Duke
will use all the DO enhancement capability available on all hydro units that are
12

Section 3 Oveiview of the Catawba- Wateree Relicensing Process
subsequently operated at that powerhouse, if needed, in its best efforts to raise DO
levels.
■ If Total Maximum Daily Loads (TMDL) are developed within the FERC Project
Boundaries (or on the Catawba and Wateree rivers and their associated floodplains and
bottomlands from Lake James downstream to the confluence of the Wateree River with the
Congaree River) for pollutants that are introduced as a direct result of operation of Project
facilities, Duke will actively consult with the appropriate state agencies including, but not
limited to, data - sharing, modeling, and sampling, to determine what role, if any, Project
operations play in managing the pollutant.
■ If, after all planned flow delivery and water quality enhancement modifications required in
the FERC- approved FWQIP have been completed, a chronic non - compliance with 401
Water Quality Certification requirements exists as a result of Duke's hydroelectric
operations, Duke will immediately consult with South Carolina Department of Health and
Environmental Control (SCDHEC) and /or the North Carolina Division of Water Quality
( NCDWQ) as appropriate to confirm the assessment of the non - compliance and the
proposed corrective action(s). Duke will continue, in consultation with NCDWQ and /or
SCDHEC, to develop an implementation plan for corrective actions.
■ If Duke believes that an inability to comply with any terms or conditions of any 401 Water
Quality Certification is not attributable to Duke's operations or is attributable to increased
waste loadings (compared to waste loadings present at the time of Project equipment
installation) from point or non -point sources, Duke may provide data to NCDWQ and /or
SCDHEC as appropriate to (i) help determine whether it is Duke's operations or other
sources that are causing Duke's inability to comply and /or (ii) support any TMDL
proceeding or other corrective actions to address these point and non -point source
loadings.
The stability and success of the negotiated CRA is sensitive to regulatory decisions (such as
North Carolina and South Carolina 401 State Water Quality Certifications and articles in the
13

Section 3 Oveiview of the Catawba- Wateree Relicensing Process
New License issued by the FERC). Material changes to the proposed License Articles could
upset the balance and benefits negotiated by the stakeholders and may lead to the potential for
Parties to withdraw from the CRA or for the entire CRA to be terminated. Therefore, the Parties
to the CRA respectfully request that the states of North Carolina and South Carolina regard the
Parties' intentions and adopt the water quality provisions of the CRA as conditions of the 401
certification without material modification.
3.5 Applicable Sections of the CRA
The CRA covers a wide range of operating and resource topics, some of which are not related to
water quality certification. The water quality certification should be based on the following
applicable sections of the CRA:
■ 2.0: Reservoir Elevation Agreements
■ 4.0: Habitat Flow Agreements
■ 6.0: Low Inflow Protocol Agreements
■ 7.0: Maintenance and Emergency Protocol Agreements
■ 13.0: Water Quality Agreements
■ 15.0: Gauging and Monitoring Agreements Sections 15.1 through 15.5
■ Appendix A: Proposed License Articles Sections A -1.0, A -3.0, A -4.0, A -5.0, and A -6.0
■ Appendix A: Proposed License Articles Section A -2.0 for Maximum Flows, Wylie High
Inflow Protocol, Flows Supporting Public Water Supply and Industrial Processes, and
Flow and Water Quality Implementation Plan
■ Appendix C: Low Inflow Protocol (LIP) for the Catawba - Wateree Project
■ Appendix D: Maintenance and Emergency Protocol (MEP) for the Catawba - Wateree
Project
■ Appendix F: Water Quality Monitoring Plan
■ Appendix L: Flow and Water Quality Implementation Plan
14

Section 4
Water Quality Assessment Process
The purpose of this section is to give water quality resource agencies and interested reviewers an
explanation of how water quality was addressed in the Catawba - Wateree Relicensing Process
and where to find the necessary analyses and findings in this application. The water quality
assessment process utilized for the Project can be explained in three distinct phases:
1. Existing aquatic resources and uses (Section 4.1)
2. Discrete Bubble Model (DBM) analysis of proposed aeration modifications (Section 4.2)
3. Assessment of operating scenarios (Section 43)
4. Quality Assurance Project Plan (QAPP) (Section 4.4)
4.1 Existing Aquatic Resources and Uses
Water quality regulations require (1) that waters be suitable for aquatic life propagation and
maintenance of biological integrity, wildlife, secondary recreation, and agriculture; and (2) that
sources of water quality pollution that preclude any of these uses on either a short -term or long-
term basis be considered in violation of a water quality standard. This water quality standard
addresses the need for any receiving waters to be of suitable quantity and to not degrade existing
aquatic communities.
The Project relicensing process determined the menu of aquatic resources and uses potentially
affected by hydroelectric operations that needed to be studied. A full list of studies is presented
in Section 3 (Overview of the Catawba - Wateree Relicensing Process) of this SIP. Additional
information about the studies that specifically focused on aquatic resources and other existing
uses is summarized in Table 3. These studies were planned and conducted in consultation with
representatives from state and federal resource agencies, and others who participated on the
Water Quality, Aquatic, and Terrestrial Resource Committees. This process provided for
thorough assessments of the aquatic resources of the Project as well as a basis for stakeholder
negotiations leading to the CRA.
15

Section 4 Water Quality Assessment Process
TABLE 3
STUDIES RELATED TO THE AQUATIC RESOURCES OF THE
CATAWBA - WATEREE PROJECT
Title (Designation)
Description
Objectives
Fish Community Smvey
Smvey of Fish Communities
■ Conduct fish community suiv eys, including
and Assessment
within and Adjacent to the Project
small non game species, in bypasses, tailrace
(Aquatics 01)
Area
areas, riverine reaches, and major tributaries of
the Project
■ Conduct field sampling to assess presence and
relative abundance of robust and Carolina
redhorses and highfin caipsuckers in the free -
flowing river reaches downstream of
Bridgewater, Wylie, and Wateree
Developments
Reseivoir Fish Habitat
Determine the shallow water fish
■ Identify magnitude, season frequency, and
Assessment
habitat available in reseivoir water
duration of water level fluctuations in each
(Aquatics 02)
level fluctuation zones and
reservoir.
determine the relationship of
■ Evaluate vertical distributions of the major
habitat to Project operations
types of shallow water fish habitat (i.e.,
emergent vegetation. large woody debris, riprap
and piers), along with clay, sand, and cobble
substrates that are included and defined in
Duke's current Catawba - Wateree Shoreline
Management Plan.
■ Assess changes in the lake -wide surface area of
these habitat types under various water level
changes associated \with Project operations.
Diadromous Fish Studies
Evaluate status and potential for
■ Document the current usage of the Wateree
(Aquatics 03)
diadromous fish restoration in the
River, below Wateree Dam, by target
Catawba - Wateree River
diadromous species during spawning seasons.
Instream Flow
Determination of aquatic habitat at
■ Quantify or otherwise assess the relationship of
Assessment
various flows in downstream river
flow to aquatic habitat in selected downstream
(Aquatics 04)
and bypassed stream reaches
river and bypassed stream reaches.
Mussel Smvey (Aquatics
Smvey of Mussel Populations in
■ The study objective is to conduct a field survey
06)
the Project Area
of mussels at sites along the Catawba River that
are within the Project boundary or within the
zone of Project influence. Each survey is
designed to provide basic information
concerning mussel occurrence with special
emphasis on Protected, Endangered, Threatened
and Special Concern (PETS) species that might
be identified in the areas.
Macrobenthic Survey
Describe the aquatic
■ The study objective is to provide basic
(Aquatics 07)
macroinvertebrate assemblages
information about hydro - related macrobenthic
associated with the Catawba-
communities and evaluate any potential Project -
Wateree Project and evaluate any
related effects on macrobenthic resources.
potential Project - related impacts
16

Section 4 Water Quality Assessment Process
Title (Designation)
Description
Objectives
RTE Species and Habitat
Document any known or
The objectives of this RTE plant and wildlife study
Suivey (Terrestrial 04)
potentially occurring rare,
are to:
threatened, and endangered (RTE)
■ Document the occurrence of RTE species
plant and wildlife species within
within the Project area:
the Project boundary and areas
■ Assess the potential effects of Project - related
within the Project influence
current and proposed hydropower operations
areas on the species and critical habitats: and
■ Provide information to assist in developing any
potential protection, mitigation, and
enhancement (PM &E) measures.
As part of the consultation process, Resource Committee members developed reports based on
study results to inform stakeholders of:
■ The overall status and condition of the resource and identify problems that may exist;
■ Potential sources of the problems affecting the resource; and
■ Recommended Project engineering or operational changes to achieve stakeholder
expectations for each resource.
Recommended operational changes to benefit existing resources frequently called for water
quality improvements, increased flow releases into riverine sections of the Project, and higher
reservoir level controls. These operational changes conflicted with each other and had to be
balanced not only with each other, but with future water needs and uses throughout the basin in
both North Carolina and South Carolina for the long term (50 years).
The balancing process explained in detail in Section 3 (Overview of the Catawba - Wateree
Relicensing Process) of this SIP was used to create a sustainable basin -wide, long -term operating
plan that also succeed at achieving enhancement goals for existing uses. If at any location
resource goals were not achieved, mitigation by Duke was agreed to (refer to Section 6 [Flow
Mitigation Package] of this SIP). Each Project development is discussed in Section 5 (Individual
Developments) of this SIP, including the existing uses considered and how they were addressed
and enhanced.
17

Section 4 Water Quality Assessment Process
4.2 Discrete Bubble Model Analysis of Proposed Aeration Modifications
The process used to evaluate compliance with water quality standards for the water released from
each development is summarized in the following chart:
FIGURE 3
DISCRETE BUBBLE MODEL APPLICATION AND CALIBRATION FOR THE
CATAWBA - WATEREE PROJECT
Initial Turbine Tests
Discrete Bubble Model
Field Testing and
Calibration
Discrete Bubble Model
Aeration Curves for
Each Unit
Predicted Dissolved
Oxygen Concentrations
18

Section 4 Water Quality Assessment Process
4.2.1 Assessment of Tailrace Water Quality
Beginning in 1992 as a research project at Lookout Shoals tailrace, installation of electronic
equipment for water quality monitoring at 5- minute intervals (temperature, DO, conductivity,
and pH) was completed for all Project development tailraces by 1996 (refer to Duke Energy
2006 for detailed methodology and time series plots). For 5 years beginning in 1997, water
samples were collected in the tailraces at 2 -week intervals. Detailed nutrient, metal, and ionic
composition analyses were performed on these bi- weekly samples. This tailrace water quality
data, collected at such frequency, provided detailed information regarding station operation and
clearly demonstrated that all applicable state water quality standards were met year - round, with
the exception of DO, in the turbine releases.
The water quality numerical assessments presented in this application are based on multiple
years of water quality sampling preceding the Catawba - Wateree Relicensing Process and
additional sampling conducted in 2004 as part of the relicensing process. This is a more
extensive database than is commonly available for most certification processes. This extensive
data range (1) reflects a comprehensive range of hydrologic (temperature and DO) and
operational (flow release rates and unit operating combinations) conditions which are evaluated
in this application and (2) helps to assure the adequacy and resiliency of the proposed DO
enhancement measures better than could be anticipated based on the more typical one to two
years of water quality sampling. Most importantly, this extensive database allowed a detailed
analysis and evaluation of DO compliance with state standards.
In 1995, Duke began evaluating options to increase the DO in the turbine releases. Technologies
such as forebay aeration (air and liquid oxygen injection), turbine venting, forebay strictures
(curtains, walls, weirs, etc.), tailrace aeration weirs, and direct air injection were evaluated for
each Project development. Analysis of the long -term DO database provided the design criteria
for evaluation of the various options. Turbine venting was the technology of choice due to cost
effectiveness, long -term reliability, rapid introduction of oxygen, and the immediate response of
increased DO to the turbine flow.
19

Section 4 Water Quality Assessment Process
Turbine venting was also considered the preferred aeration technique for the Project based on its
proven applicability at other hydropower projects. It is estimated that some form of turbine
venting is used or is being planned at over 70 hydropower projects throughout the country.
Based on these evaluations, turbine venting modifications were completed as Duke upgraded
some of the hydro units as part of the refurbishment program in the 1990s.
4.2.2 Initial Turbine Tests
As individual unit modifications were completed, DO uptake studies were performed to evaluate
the amount of DO added to the released water. Results of these early turbine venting studies
clearly showed that autoventing (air released at the trailing edge of the turbine runner) was
superior to other forms of turbine venting (Figure 4). However, because autoventing turbines
could not be retrofitted to existing turbines, existing turbines had to be replaced entirely. Even
though hub and stay vane venting were not as efficient as the recently invented autoventing
technology, they were options that could be retrofitted to existing turbines at a reasonable cost.
The results of field testing were highly variable (Figure 4), with oxygen uptake values typically
lower at higher flow rates (greater wicket gate openings). Although the results of these initial
turbine tests were encouraging, the data could not be used for predictive purposes to evaluate the
use of turbine venting for compliance with DO standards.
Clearly, a method was needed to be able to predict the effectiveness of turbine venting as a
means to meet state DO standards. The turbine venting aeration at each station must meet DO
standards for all future flow conditions (e.g., single -unit flows, multi -unit flows, and minimum
flows) at all levels of incoming DO. The station operations and tailrace DO concentrations
measured during the long -term monitoring program will be used to evaluate future aeration
effectiveness and DO compliance.
20

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Section 4 Water Quality Assessment Process
4.2.3 Discrete Bubble Model — Field Testing and Calibration
The DBM (DBM) was selected for use on the Project because it includes a more mechanistic
description of the factors affecting gas transfer and has several advantages over previous turbine
venting models for predicting aeration beyond the range of conditions for which data are
available and the models are calibrated. In its simplest form, the bubble model takes the form:
A DO = E (DO51t — DOi„)
Where:
DO = DO concentration
A DO = DO concentration increase across the turbine
DO51t = saturation DO at local temperature and pressure
DOi„ = DO incoming to the hydroplant
E = aeration efficiency (dimensionless, varies from 0 to 1 depending on physical
factors)
DO,,t decreases as water temperature increases, and increases as draft tube pressure
increases.
If DOi„ = DO51t, there is no uptake of DO across the plant (A DO = 0)
E increases with:
Decreasing water temperature
Time of travel through the draft tube (function of draft tube length, diameter, and
turbine flow)
Pressure in the draft tube (function of how deep the draft tube extends below
tailwater level)
Smaller bubble size and bubble distribution in the draft tube flow (function of
turbine flow)
Air flow rate (function of turbine elevation above tailrace level, turbine flow, air
valve inlet size)
Turbine flow (function of turbine design, net hydraulic head, wicket gate opening)
Tailrace elevation (function of total plant flow)
22

Section 4 Water Quality Assessment Process
Field testing the Project turbines for application to the DBM was initiated in 2002 at the Wylie
Development, and the remaining developments were tested in 2006. The basic protocol for field
testing was to vary the unit flow, starting with the lowest flow with no aeration, and to repeat the
flow with aeration. Incrementally the flow was increased, and the procedure repeated. At each
flow setting and aeration setting (on or off), the following parameters were measured:
• Power Output (MW)
• Wicket Gate Setting ( %)
• Forebay Elevation (ft)
• Tailrace Elevation (ft)
• Air Flow into Turbine (modified bell mouths) (cfs)
• Head Cover Pressure (Pa)
• Water Temperature ( °C)
• Tailrace DO without Aeration (measured in the flow as it left the turbine) (mg /1)
• Tailrace DO with Aeration (measured in the flow as is left the turbine) (mg /1)
For a complete discussion of the methodology, equipment, and procedures, please refer to the
Wylie model report presented in Appendix C.
Using Rhodhiss as an example to illustrate the development and use of the DBM, the initial
calibration required for the DBM was the relationship of DO uptake and unit air flow (Figure 5).
23

Section 4 Water Quality Assessment Process
FIGURE 5
PRELIMINARY DATA ASSESSMENT OF RHODHISS DEVELOPMENT TURBINE
VENTING TEST FOR DISCRETE BUBBLE MODEL
2.5
2.0
m
E
Y
a 1.5
D
m
X
a 1.0
0
0
w
0.5
Rhodhiss - Turbine Venting
Field Test - July 2006
(approximately 4.5 mg /I inflow concentration)
Unit 1 - DO uptake "" "Unit 2 - DO uptake S Unit 1 - Airflow —0 Unit 2 - Airflow
❑ 1111
�
0.0
1000
1200 1400 1600 1800 2000 2200 2400
Turbine Water Flow (cfs)
90
85
80
75
70
3
0
65 Q
0
60 n
H
55
50
45
40
2600
Calibration of the DBM to each hydro unit tested began with performing regression analyses on
various interrelated parameters. For example, tailwater elevation is a function of total hydro
station flow, percent decrease in air flow is a function of increase in tailwater elevation, turbine
air flow is a function of turbine water flow, etc. The geometry of the draft tube (unique for each
unit) was developed and incorporated into the DBM program (draft tube geometry, along with
unit water flow determines water velocity, bubble size, and travel time). Next, using the
variables in the equation (e.g., DO measured in the turbine inflow, the DO measured in the
outflow, airflow into the turbine, temperature, hydro station flow, and tailwater elevation), the
model was iteratively run to find the bubble size that most closely matched the measured DO.
The initial bubble size versus hydro station flow was then plotted; the resulting data has been
found usually to fit a power curve (Figure 6). It is then possible to calculate outflow DO based
on the bubble size relationship to the turbine flow. Using this method, the predicted outflow DO
24

Section 4 Water Quality Assessment Process
is very close to the measured outflow DO, as shown in Figure 7. For a complete discussion of
DBM calibration, see Appendix B.
FIGURE 6
CALIBRATED BUBBLE SIZE WITH PROJECT FLOW
6
y 3E-13X4 3E-09X3 + 2E-05X2 0.0352x + 28.655
5
E
E 4
N
3
m
2
m 1
0
1000 1500 2000 2500 3000 3500 4000
Q (Cfs)
25

Section 4 Water Quality Assessment Process
FIGURE 7
COMPARISON OF MEASURED DISSOLVED OXYGENTO DISCRETE BUBBLE
MODEL - PREDICTED DO
Using the general process described above, a DBM unique to each turbine was calibrated from
the field data. Complete field aeration data (air flow, water flow, initial DO, temperature, DO
uptake, and turbine power output) was collected in 2002 for two units at Wylie and in 2006 for
12 units at other Catawba - Wateree developments. Units were chosen for field testing if the units
were unique or representative of other identical units (turbine size, draft tube geometry, air inlet
configuration, etc.). A DBM was also developed for future units at Rhodhiss, Oxford, Wylie, and
Wateree. For the new units specified by the CRA at Wylie and Wateree, an existing DBM
matching the turbine configuration (e.g., draft tube geometry) was used with the air flow
modified and the water flow changed to match the flow levels required by the CRA.
26

Section 4 Water Quality Assessment Process
4.2.4 Discrete Bubble Model — Aeration Curves for Each Unit
A calibrated DBM was applied to each turbine at each hydroelectric development in the Project
and used as a tool to predict the effectiveness of existing and future turbine aeration capabilities.
The model was also used to evaluate piping modifications needed to provide additional air flow
to the water in the turbine. Unit aeration capabilities were developed for each development
(Figures 8 through 10, using the Rhodhiss Development as an example).
FIGURE 8
AERATION CAPABILITY OF THE THREE UNIT TYPES AT THE RHODHISS
DEVELOPMENT UNDER ONE -UNIT OPERATION
9.0
8.0
rn
E
7.0
a�
rn
x 6.0
O
> 5.0
0
U)
p 4.0
3
0
3 3.0
O
a�
2.0
n
~ 1.0
• Unit 1 (Stay Vane)
• Unit 2 (Stay Vane)
• Unit 3 (Future Auto Venting)
Rhodhiss Hydro - Unit Aeration
Singly Unit C)p ration
® ® Unit 1, minimum turbine flow
® Unit 2, minimum gate
Unit 3, minimum turbine flow
Unit 1, maximum turbine flow
Unit 2, maximum gate
Unit 3, maximum turbine flow
0.0 �_
0.0
1.0 2.0 3.0 4.0
Turbine Inflow Dissolved Oxygen (mg /1)
27
5.0 6.0
o
° o
°
0.0 �_
0.0
1.0 2.0 3.0 4.0
Turbine Inflow Dissolved Oxygen (mg /1)
27
5.0 6.0

Section 4 Water Quality Assessment Process
FIGURE 9
AERATION CAPABILITY OF THE THREE UNIT TYPES AT THE RHODHISS
DEVELOPMENT UNDER TWO -UNIT OPERATION
9.0
8.0
rn
E
c
7.0
a�
rn
x 6.0
O
> 5.0
0
U)
p 4.0
3
0
3 3.0
O
a�
2.0
n
~ 1.0
0.0
Rhodhiss Hydro - Unit Aeration
Two Unit C)peration
• Unit 1 (Stay Vane) Unit 1, minimum turbine flow Unit 1, maximum turbine flow
• Unit 2 (Stay Vane) Unit 2, minimum gate Unit 2, maximum gate
• Unit 3 (Future Auto Venting) ° Unit 3, minimum turbine flow Unit 3, maximum turbine flow
0.0 1.0 2.0 3.0 4.0
Turbine Inflow Dissolved Oxygen (mg /1)
28
5.0 6.0
° o o °
° ° °
0.0 1.0 2.0 3.0 4.0
Turbine Inflow Dissolved Oxygen (mg /1)
28
5.0 6.0

Section 4 Water Quality Assessment Process
FIGURE 10
AERATION CAPABILITY OF THE THREE UNIT TYPES AT THE RHODHISS
DEVELOPMENT UNDER THREE -UNIT OPERATION
9.0
8.0
rn
E
c
7.0
a�
rn
x 6.0
O
> 5.0
0
U)
p 4.0
3
0
3 3.0
O
a�
2.0
n
~ 1.0
0.0
Rhodhiss Hydro - Unit Aeration
Three Unit C)p ration
• Unit 1 (Stay Vane) Unit 1, minimum turbine flow Unit 1, maximum turbine flow
• Unit 2 (Stay Vane) ® Unit 2, minimum gate Unit 2, maximum gate
• Unit 3 (Future Auto Venting) Unit 3, minimum turbine flow Unit 3, maximum turbine flow
0.0 1.0 2.0 3.0 4.0 5.0 6.0
Turbine Inflow Dissolved Oxygen (mg /1)
These plots represent graphically what the DBM computes mathematically for each turbine flow,
total hydro station flow, inflowing DO, and temperature. Even though the aeration appears
similar at all hydro station flows, in reality, as the hydro station flow increases, the tailwater
elevation increases, thereby slightly decreasing the air flow to the units. This in turn causes a
slight decrease in the DO added to the released water. As can be seen in the Rhodhiss examples,
the future autoventing turbine is assumed to be Unit 4 and will have the highest DO uptake
(specifically designed to aerate), whereas the aeration from Unit 2 generally exceeds the aeration
capacity of Unit 1.
29
o
. .
0.0 1.0 2.0 3.0 4.0 5.0 6.0
Turbine Inflow Dissolved Oxygen (mg /1)
These plots represent graphically what the DBM computes mathematically for each turbine flow,
total hydro station flow, inflowing DO, and temperature. Even though the aeration appears
similar at all hydro station flows, in reality, as the hydro station flow increases, the tailwater
elevation increases, thereby slightly decreasing the air flow to the units. This in turn causes a
slight decrease in the DO added to the released water. As can be seen in the Rhodhiss examples,
the future autoventing turbine is assumed to be Unit 4 and will have the highest DO uptake
(specifically designed to aerate), whereas the aeration from Unit 2 generally exceeds the aeration
capacity of Unit 1.
29

Section 4 Water Quality Assessment Process
4.2.5 Application of the Discrete Bubble Model to Hourly Historical Data
The evaluation of turbine venting to meet state DO standards was conducted by applying the
appropriate, calibrated DBM to each turbine at each hydro development. Hourly data (measured
hydro station flows, temperature, and DO from the continuous monitoring record) were used as
input to the calibrated turbine DBM models at each development. The total project historic flows
were allocated to the various units based upon each unit's flow capacity. When the historic
project flow exceeded the capacity of one unit, then subsequent units were assumed to operate.
Using two different days as examples from the Rhodhiss historical records, the DBM was
applied to each unit needed to release the historical flow rate in order to calculate hourly DO
concentrations. In addition, the daily average DO was also calculated for the Rhodhiss
Development for illustrative purposes and presented in Tables 4 and 5 below.
30

Section 4 Water Quality Assessment Process
TABLE 4
DISCRETE BUBBLE MODEL APPLICATION TO PREDICT FUTURE STATION
TAILRACE DISSOLVED OXYGEN: EXAMPLE OF FLOW ALLOCATION TO THE
RHODHISS DEVELOPMENT WHEN 2 UNITS WERE OPERATING
Historical Flows �� 7r� ,u{ �� ',Vr� ,A�(iikr�':
�(i Gi 7���.1 ii41 Ott (f {4} f t ii nl'11 iyi ;,
Station
����%"di��t i iUpStation
Date Time
Total Tailrace
Station Station hip "
Stationer �y �rtt� ;� 1��I� Generation Hourly
(cfs) Temp DO �; t „ `� £ `rrs ti r '(r Flow DO
(C) (mg /9 st�f&? ` �� (P s ;
�`���,�;� � 1(\ � I s (cfs) (mg/1)
8/14/00 0:00 60 23.5 249 60
P�
8/14/00 1:00 60 23.3 2.33 (�„ , ' ; £ �} �' i` r 1'r� rS } ` +tl 60
8/14/00 2:00 60 23.2 2,20 Si`�r �£ pr r t �� !} �� s +r ' f s( 60
8/14/003:00 60 23.1 205 60
8/14/00 4:00 60 23.1 1.90 60
8/14/00 5:00 60 23.0 1,64
60
8/14/00 6:00 60 22.8 162 l {t fr g� irttit� i 60
8/14/00 7:00 60 22.7 1.54 60
8/14/008:00 60 22.6 1.42 ''�(} �� rsl �� ;�� '` +Q�i� �' £ ' "I,`s 60
8/14/009:00 60 22.6 1, 66s�£ r`,� �� ,0, '�� �j" �`�(�} �} r i,:r`!
60
8/14/00 10:00 60 22.6 2.06 �Yj 60
��
8/14/00 11:00 1405 23.0 2,66 jj , (r ,� t g 1405 6.87
i
8/14/0012:00 2120 23.9 033 0 0 2�2f1, ih rs, 2120 7.08
r 0f
8/14/00 13:00 3710 24.0 3.36 3710 6.21
8/14/00 14:00 4476 24.3 3.46 0 rs.r 3� £ �� `r �' `22$� s1�r' 4476 6.20
8/14/0015:00 4426 24.0 304 (� {i£�} it,�,sr�t;227 >}14 13 r 4426 5.94
i�t
8/14/00 16:00 5253 23.8 2.91 5253 5.77
1 V £(S +� it r S (z\ yr �i
8/14/00 17:00 5052 29.0 3.10 4£ 1� t i�'' 25tfa }2J 5052 5.92
8/14/0018:00 1472 24.2 393 ",�;,4�; %r� ` rrt£ " 't`r0r1��f{ tl £ �4t�2 +�' ,t74a 1472 7.45
8/14/00 19:00 60 24.2 3.81 t r { , t 60
8/14/0020:00 60 24.2 £ £( � 60
8/14/00 21:00 60 24.2 3.83
{� t �r ¢ £ � y£ r�£yy4
60
8/14/0022:00 60 24.3 393
60
8/14/0023:00 60 241 3.88 ;r��,'S,?,�,�{ r 4_<:`.,.,.`,,.?,.?, «:,.• t�A'„'r
60
Daily Average DO = 6.43
31

Section 4 Water Quality Assessment Process
TABLE 5
DISCRETE BUBBLE MODEL APPLICATION TO PREDICT FUTURE STATION
TAILRACE DISSOLVED OXYGEN: EXAMPLE OF FLOW ALLOCATION TO THE
RHODHISS DEVELOPMENT WHEN 3 UNITS WERE OPERATING
The frequency of occurrence of all hourly DO values (both historical and predicted values) were
calculated at 0.1 mg /1 intervals. The cumulative frequencies were then plotted and compared for
compliance with state standards (hourly Rhodhiss values are shown in Figure 11). The same
technique was applied to the observed and predicted daily average values. These compliance
plots, as well as the number of hours (days) not meeting state standards were calculated and
plotted for all projects.
32
Historical Flows
r
�StY1('
Station
,e
utQ,expt „
Date / Time
>
Station
,'
9
I
Total Tailrace
Station
Station
t OrtM
�i a '
Plttlt(0t ,�
rt�T *Itrad
Ti
}" r(t
Generation Hourly
Temp DO
Igy� t Sl
,�F�CQvi
Flow DO
( c) (mg /9
f&)
(f s
(cfs) (mg /1)
8/7/000:00
60 24.1 323,0
�(�`�y ��{
sf +�r0IJ
60
8/7/00 1:00
60 24.1 3.20
�t` (�
Ai'y
' ` � '
60
8/7/00 2:00
60 23.9 3.09
s
fib t
�5�
{f, ,i4
0 s
�
60
8/7/00 3:00
60 23.9 3 01
i
i,
, ; <<
60
8/7/00 4:00
60 23.8 2.90
f z
�� r } y,
8/7/00 5:00
60 23.9 2.58
60
8/7/00 6:00
60 23.8 2.54
�,� + �)� +'
` 0i {�� ` �`
s s ' ` "'
60
8/7/00 7:00
60 23.8 2.37
60
8/7/00 8:00
60 237 2.37
'P1
60
t ti?
8/7/00 9:00
1450 23,7 2.42
�`f,0' r r r
1450 6.67
8/7/00 10:00
1881 237 3.09
s
tj{ r' (r ��
`
„s8$'t ,8��,t
1881 6.99
8/7/00 11:00
2185 23.7 3.25
21i
2185 7.05
8/7/00 12:00
6920 23.7 3.02
6920 5.41
8/7/0013:00
1414 241 331
�r',,f, +? ,''t
f1"
1414 7.13
8/7/00 14:00
4717 24.3 317
`;$ r �',+
} $�
X35$ t ,' i ff5 '
4717 6.06
8/7/00 15:00
4719 24.4 3.24
f 4 { }
41 { t }
N 5 1 f'
4719 6.03
8/7/00 16:00
1414 24.5 3.24
,i
0t,t yrlr �;iynt
�
7�`4�} i'y
1414 7.06
8/7/00 17:00
60 24.6 3.28
i �{ r t + sti r
0
60
8/7/00 18:00
60 24.7 3 33
t
, } y i
,
�s
60
8/7/00 19:00
60 24.5 3.26
60
8/7/00 20:00
60 24.5 3.47
iit rY
'tl �'' `�i�
rt 3i .lit
0
r,r /
0 i i `j
60
8/7/00 21:00
4330 24.4 346
s't
,
2 (�5 );f 52T�{
213 7, �5
4330 6.21
8/7/00 22:00
1756 24.4 3 54�
( , t ; �/i
�� �" , Si' r
,r
i (�%�s,' {j�
1756 7.19
8/7/00 23:00
60 24.3 3.49
its
�
�� 1'+;t ��r ,'
i� ,s {rr{
60
{
Daily Average
DO = 6.58
The frequency of occurrence of all hourly DO values (both historical and predicted values) were
calculated at 0.1 mg /1 intervals. The cumulative frequencies were then plotted and compared for
compliance with state standards (hourly Rhodhiss values are shown in Figure 11). The same
technique was applied to the observed and predicted daily average values. These compliance
plots, as well as the number of hours (days) not meeting state standards were calculated and
plotted for all projects.
32

Section 4 Water Quality Assessment Process
FIGURE 11
FREQUENCY OF COMPLIANCE WITH STATE WATER QUALITY STANDARDS
FOR HOURLY DISSOLVED OXYGEN AT THE RHODHISS DEVELOPMENT
CALCULATED FROM THE DISCRETE BUBBLE MODEL AND COMPARED TO THE
12
a
i-4
O
U
U
O
li
HISTORICAL RECORD
Rhodhiss
Total Number of Hours = 24,242
I I I I I I I I I
I I I I I I I I I
i'yryryn I I I I I I I I I
`aw""'n.wm
,,,non, a
I I - - - -- ���a"axia�i I I I T T T
I I I imyar � I I I I I
"+w,aya I I I I I
I I I I I I I I
I I I I I I I I I
T T T I— — — — — — — — — — — — T T T
\\y�pU„pppq`p`\" I
..
............
I I I I I I I I I
I I I I I I I I
I I I I I I I I I ,,.
r Instantaneous DO standard
I I I I I
- - - - - Hourly with aeration - - - - - � T
I I I I I
I I I I I
Hourly without aeration
I I I I I
I I I I I
I I I I I I I I I
10 20 30 40 50 60 70 80 90 100
Frequency Exceeding DO Concentration ( %)
The compliance charts for hourly and daily average oxygen (DO) concentrations in the tailrace
of each Catawba - Wateree development in North Carolina (listed in Section 5 [Individual
Developments]) provide assurance that each development will be capable of meeting or
exceeding the 4.0 mg /L state standard for instantaneous DO concentration and the 5.0 mg /L state
standard for daily average DO concentration after the modifications described in the CRA for
each development are installed.
33

Section 4 Water Quality Assessment Process
The compliance chart shows the cumulative frequency (percent) of the dissolved oxygen (DO)
concentrations at or above a given DO level based on historical hourly generation. The dark red
line shows DO frequencies for the station without turbine aeration, whereas the blue line shows
DO frequencies with post - license turbine aeration as described in the CRA.
4.2.6 Conservative Assumptions of Applying the Dynamic Bubble Model to
Predict Future Compliance with Water Quality Standards
The prediction of future tailrace DO concentrations at the Project employ numerous factors.
Factors involving the data and application of the DBM which lead to conservatisms in the
prediction of tailrace DO include:
■ DO Sensor Fouling
■ Projection of future Reservoir DO levels
■ Operational considerations
■ Additional sources of aeration
DO Sensor Fouling
The standard Clark Cell used to measure tailrace DO was very prone to fouling. Organic slime,
inorganic accumulations, membrane hysteresis, etc. would change the integrity of the Teflon
membrane, changing the calibration of the sensor. Even though the instruments were replaced,
cleaned, and calibrated approximately every 2 weeks, with more frequent maintenance during the
summer months, the sensors would lose their calibration. The average fouling rates (Table 6) at
each hydro provide an estimate of the error of the long -term measurements. Unlike the method
used by the USGS (Wagner et al. 1999), the historical continuous DO data were not "corrected"
for instrument calibration errors. These data imply that, on the average, the historical DO
concentrations and, consequently, the calculated DO uptake from the DBM, would typically
yield underestimates of the actual DO values by 0.55 mg /1 (range of 032 -0.88 mg /1).
34

Section 4 Water Quality Assessment Process
TABLE 6
AVERAGE DISSOLVED OXYGENSENSOR FOULING RATES
Development
Average Fouling Rate
(mg/l per deployment)
Average Deployment
Time (days)
Bridgewater
-0.32
14.9
Rhodhiss
-0.72
14.8
Oxford
-0.81
14.4
Lookout Shoals
-0.48
14.6
Cowans Ford
-0.51
14.3
Mountain Island
-0.37
14.1
WvIie
-0.62
12.9
Fishing Creek
-0.23
12.8
Great Falls - Dearborn
-051
12.2
Rocky Creek -Cedar Creek
-0.66
12.3
Wateree
-0.88
12.8
Projection of Future Reservoir DO Levels
The application of the DBM to data recorded since 1996 to predict future DO levels implies that
the DO concentration in the water supplying the turbines would be of similar concentrations in
the future (for the term of the New License). However, with the state water quality agencies and
various groups actively pursuing various initiatives to improve water quality (e.g., Charlotte
Mecklenburg Utilities agreement with SCDHEC to reduce nutrient input to Fishing Creels
Reservoir), the DO in the reservoirs is not expected to decline, but rather DO is expected to
increase as nutrient loading is reduced to the lakes as TMDLs are implemented and completed.
Operational Considerations
The first step in the application of the DBM to historic data was the allocation of historic flows
to the various units at each hydro. A computer program allocated the flows to each unit based
upon that unit's range of operations. For example, if the historical project flow exceeded the
flow of an individual unit, the excess flow would be routed through another unit to calculate the
predicted tailrace DO. However, operators can make decisions to utilize the most efficient
aerating units and re- balance unit flows to the levels yielding the most effective aerating results.
Instead of an automatic flow allocation, an operator may adjust the flow as necessary to comply
with state standards, thereby optimizing the power output and water quality compliance.
35

Section 4 Water Quality Assessment Process
Choices made by operators to adjust unit flows were not considered in the use of the DBM to
predict future tailrace DO levels.
Additional Sources of Aeration
Additional sources of DO may be provided by natural aeration in the bypassed reaches and by
the higher natural aeration of minimum flows compared to generation flows (increased surface to
volume ratio of the minimum flows). These processes, as with fouling rates, were totally ignored
in estimating future DO levels and provide additional conservatism to the DBM predictions.
Also ignored in the tailwater DO estimates was the additional aeration provided by combined
unit flow. Units with high aeration capacity adjacent to units with lower aeration efficiency
would tend to add additional oxygen to the mixed flow. Throughout the turbine testing, DO
levels in combined flows of high and low aerating units were observed to be greater than the
flow - weighted average of individual flows.
4.3 Assessment of Operating Scenarios
Water quality modeling conducted after an operational scenario was agreed upon by stakeholders
enabled a relative comparison of whether proposed future CRA operations may be expected to
have an enhancing, degrading, or neutral influence on various reservoir parameters. This
assessment supplements the required tailwater water quality certification assessments by
examining parameters that are not directly addressed by water quality standards and existing uses
in the hydro station tailraces and riverine sections.
NCDWQ and SCDHEC realize that changes in the flow regime at Project developments as a
result of the implementation of the CRA could potentially impact water quality within a reservoir
and /or in the downstream riverine reach. Since actual, long -term test demonstrations and
subsequent water quality measurements were impractical, computer models (U.S. Army Corps of
Engineers [USACOE] CE- QUAL -W2 model) were developed and calibrated for most Project
reservoirs. These calibrated computer models were then used to evaluate the water quality of the
Project waters by applying the CRA operating provisions to a "normal ", "high flow ", and "dry"
36

Section 4 Water Quality Assessment Process
year. The specific daily flows produced by the CHEOPS model were used in the specific CE-
QUAL-W2 model to predict the reservoir water quality under the New License operating
provisions that would be expected in the various flow years. The results of the computer
modeling were compared for current operation and future operation. The Water Quality
Resource Committee defined the issues within each reservoir for comparison. For example,
walleye habitat was an important issue in Lake James because temperature and DO define the
quantity of this species' habitat in the lake. The volume of habitat was compared between
current day operations and future CRA operations.
Section 7.2 (Assessments of Operational Scenarios) of this application explains this modeling in
more detail, including the metrics considered and the results of current day operations compared
to operations under the CRA.
4.4 Quality Assurance Project Plan
Appendix A of this SIP presents a detailed description of the QAPP that is proposed for the
Proj ect.
37

Section 5
Water Quality Assessment and Improvements —
Individual Developments
5.1 Bridgewater Development
The Bridgewater Development consists of the following existing facilities: (1) the Catawba Dam
consisting of. (a) a 1,650- foot -long, 125- foot -high earth embankment, (b) a 305- foot -long, 120 -
foot -high concrete gravity ogee spillway, and (c) a 850- foot -long, 125- foot -high earth
embankment; (2) the Paddy Creek Dam consisting of a 1,610- foot -long, 165- foot -high earth
embankment; (3) the Linville Dam consisting of a 1,325- foot -long, 160 - foot -high earth
embankment; (4) a 430- foot -long uncontrolled low overflow weir spillway situated between
Paddy Creek Dam and Linville Dam; (5) a 6,754 -acre reservoir formed by Catawba, Paddy
Creek, and Linville dams with a full pond elevation of 1,200 feet above mean sea level (ft msl);
(6) a 900 - foot -long concrete -lined intake tunnel; (7) a powerhouse containing two vertical
Francis -type turbines directly connected to two generators, each rated at 10,000 kilowatts (kW)
for a total installed capacity of 20.0 MW; and (8) other appurtenances (Figure 12).
5.1.1 Current Status
5.1.1.1 North Carolina DWQ Assessments and Water Quality Standards
The North Carolina Department of Environment and Natural Resources (NCDENR 2004)
classified Lake James as oligotrophic, with no water quality parameters identified as lake
stressors. Currently, the reservoir and the downstream riverine reach meet all of their designated
uses (primary recreation and aquatic life propagation /protection). Additionally, all of the
inflows, with the exception of a 3.5 -mile -long section on the North Fork Catawba River, are
meeting their designated uses. Significant portions of the Lake James watershed have excellent
water quality and are designated as Natural Heritage Areas, High Quality Waters, and /or
Outstanding Resource Waters.
38

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 12
BRIDGEWATER DEVELOPMENT
39

Section 5 Water Quality Assessment and Improvements — Individual Developments
Muddy Creek, a tributary of the Catawba River downstream of the Bridgewater Development, is
not considered impaired, but showed evidence of significant sediment loads, nutrient enrichment,
and fecal coliform contamination ( NCDENR 2004). No areas within the project boundary at
Bridgewater were listed by NCDENR as impaired. Impaired waters outside the project boundary
at Bridgewater that potentially influence water quality within the Project include:
■ 303(d) listings for inflows to Lake James were:
3.5 miles of the North Fork Catawba River: biological impairment
■ 303(d) listings for inflows downstream of Bridgewater were:
— 5.5 miles of Youngs Fork, tributary of N. Fork Muddy Creek: biological impairment
— 2.4 miles of Jacktown Creek, tributary of N. Fork Muddy Creek: biological
impairment
5.1.1.2 FERC Relicensing Data Summary
Reservoir - Lake James
Water Quality Findings
The following information was provided in Book 2 of 10, Application for New License
Supplement and Clarification - Study Reports (Duke Energy 2007):
■ Lake James is the second largest storage reservoir on the Catawba System. It is formed by
three earth embankment dams: one across the main stem of the Catawba River, one across
Paddy Creek, and one across the Linville River. A 10 -meter -deep canal connecting the
Catawba Basin to the Paddy Creek- Linville Basin allows the surface water of the Catawba
Basin to flow into the Paddy Creek- Linville Basin.
■ The reservoir has a relatively long retention time, averaging 208 days.
■ Duke operates the Bridgewater Development for peaking energy or downstream water
demands or the requirements of the LIP.
40

Section 5 Water Quality Assessment and Improvements — Individual Developments
■ There is currently no supplemental aeration capability being utilized at the Bridgewater
Powerhouse; however, Duke is in the process of building a new three -unit powerhouse.
Each unit will have aeration capability.
■ Lake James stores the cold, well oxygenated winter inflows. The water temperatures and
the concentration of DO are dependent upon the severity of the winter.
■ As the Bridgewater turbines release water downstream during the summer stratified period
from the deeper depths of the Paddy Creek- Linville Basin, temperatures of the deeper
water gradually increase while DO progressively decreases.
■ The turbines cannot access the deeper, coldwater stored in the reservoir formed by the
Catawba Dam due to the bathymetric restriction imposed by the connecting canal.
Therefore, the Catawba side of Lake James exhibits a very strong thermal gradient at the
depth of the connecting canal.
■ Lake James receives relatively high concentrations of nutrients and organic matter from the
North Fork Catawba and Catawba River inflows, and low nutrients and organics from the
Linville River.
■ Algae are significant near the headwaters of the Catawba arm where nutrients are high;
algal activity is low near the dams due to low nutrient levels.
■ The organic material, both received from the watershed and from the algae produced in the
lake, contribute to the lower DO concentrations in the deeper layers. This is most
pronounced in the upper Catawba basin.
■ Lake James acts as a major trap for suspended solids and phosphorus, due to sorption onto
inorganic sediments that settle out of the water column.
Biological Resource Findings
The following information on the biological resources of Lake James was provided in Book 2 of
10, Application for New License Supplement and Clarification - Aquatics 01 Study Report
(Duke Energy 2007):
■ The littoral fish community of Lake James was studied from 1994 -1997 and in 2000
utilizing spring shoreline electrofishing. Three regions were sampled: the upper Catawba
41

Section 5 Water Quality Assessment and Improvements — Individual Developments
River arm, the Linville River arm, and the lower Catawba Basin. Mean total fish biomass
averaged 191.1 kilograms per kilometer of shoreline in the upper Catawba River arm, 34.4
kg /km in the Linville River arm, and 46.7 kg /km in the lower Catawba Basin.
■ Thirty -eight species of fish, plus hybrid sunfish, were observed in shoreline electrofishing
of Lake James.
■ In the upper Catawba River arm of Lake James, littoral fish biomass was dominated by
common carp (31 percent), notchlip redhorse (29 percent), and largemouth bass (12
percent). In terms of numbers, the community was dominated by sunfish, primarily
bluegill and redbreast, which accounted for 40 percent of total fish density.
■ In the lower Catawba Basin of Lake James, black basses accounted for 46 percent of total
biomass on average (largemouth 34 percent, smallmouth 12 percent); notchlip redhorse
accounted for 19 percent; and common carp accounted for 13 percent. Sunfish (redbreast,
bluegill) were again the most numerically abundant group, averaging 57 percent of total
fish density, while black basses accounted for 25 percent.
■ In the Linville River arm, black basses averaged 53 percent of total biomass (largemouth
29 percent, smallmouth 24 percent), as compared to 21 percent for common carp. As with
other sections of Lake James, sunfish (redbreast, bluegill) dominated the community
numerically, averaging 57 percent of total fish density, while black basses accounted for 30
percent.
■ The littoral fish community of Lake James was also studied from 1983 through 1987,
utilizing summer sampling of coves with rotenone. Littoral fish community biomass in
these studies averaged 141.2 kg /ha. Gizzard shad accounted for 39 percent of total littoral
biomass on average, sunfish for 9 percent, largemouth bass 4 percent, crappie 3.5 percent,
yellow perch 3 percent, walleye 2 percent, smallmouth bass 2 percent, threadfin shad 1
percent, and white bass 1 percent.
■ Estimates of limnetic fish densities and composition of forage fish were made via
hydroacoustic (1997 and 2000) and purse seine sampling (1993 -1997 and 2000). Limnetic
forage fish densities in Lake James averaged 4,380 fish per hectare in the Catawba River
arm and 887 fish per hectare in the Linville River arm. Purse seine data indicated that
gizzard shad accounted for from 0 to 100 percent of forage fish in samples, averaging 67
percent; threadfin shad averaged 33 percent. The substantial variation among years in
42

Section 5 Water Quality Assessment and Improvements — Individual Developments
forage fish density and community composition was potentially influenced by thermal
stress to threadfin shad during severe winters.
■ Lake James is unique among the Catawba - Wateree reservoirs in that it supports not only a
warmwater fishery but a coolwater fishery as well. Of the Catawba - Wateree reservoirs,
smallmouth bass were found only in Lake James, and only Lake James maintained a
significant walleye population.
■ From 1988 through July 2001, the North Carolina Wildlife Resources Commission
(NCWRC) reported no fish kills on Lake James.
Bridgewater Regulated River Reach
Water Quality Findings
The following information was provided in Book 2 of 10, Application for New License
Supplement and Clarification - Study Reports (Duke Energy 2007):
■ Ten years of tailrace continuous monitoring at approximately 5- minute intervals for
temperature, pH, and DO revealed that only DO did not consistently meet state water
quality standards from July to September for turbine releases.
■ Coldwater releases from the Bridgewater Development enable the establishment of a
downstream trout fishery. During most summer periods, the water temperatures released
from Bridgewater meet trout habitat requirements of less than the 20 °C. However, years
with higher precipitation and flow releases deplete the coldwater reserve in Lake James at
a faster rate, with late fall water temperatures exceeding the 20 °C standard for trout by a
few degrees in the tailwaters.
■ The higher the flows released from the Bridgewater turbines, the farther downstream the
coolwater is able to persist. When there is no generation at Bridgewater, leakage water
temperatures warm rapidly due to shallow depths and warm inflow from the Catawba
River Bypassed Reach due to the contribution of Muddy Creek flow.
43

Section 5 Water Quality Assessment and Improvements — Individual Developments
■ On the average, during May through November, 24 percent of the hourly average DO
concentrations released from Bridgewater are lower than the current 4.0 mg /1 instantaneous
standard and 43 percent are lower than the 5.0 mg /1 daily average standard.
■ Year -to -year variation in the DO concentrations of the turbine releases are a function of:
— Lake James watershed loading in the winter; spring period (higher flows result in
lower DO)
— Colder winters enabled more DO at the onset of Lake James spring stratification
— Warmer autumn weather delayed the winter mixing events in Lake James,
contributing to progressively lower DO concentrations
■ Even during low flows and no generation, DO increases rapidly in downstream reaches.
Conversely, low DO from Bridgewater release is pushed farther downstream during high
turbine flow. However, even at high turbine flows with low oxygen, re- aeration
continually adds oxygen. Under worst case conditions, 5.0 mg /1 daily averages were not
achieved until approximately 7 miles downstream of the hydro station.
Biological Resource Findings
The following information on the biological resources of the Bridgewater Regulated River Reach
was provided in Book 2 of 10, Application for New License Supplement and Clarification -
Aquatics 01, Aquatics 06, and Aquatics 07 Study Reports (Duke Energy 2007):
■ The Bridgewater Regulated River Reach (RM 279.6 downstream to the confluence with
the Johns River at RM 261.5) was sampled cooperatively from 1993 through 1997 by
NCWRC and Duke. The initial 1993 survey divided this 18.1 -mile stretch of river into
four sampling areas and used boat and backpack electrofishing and baited hoop nets to
document the resident fish community.
■ Forty -five species and one hybrid combination representing eight taxonomic families were
collected. Other initial findings showed low DO concentrations and limited gamefish
populations though species diversity was high. Subsequent surveys evaluated the survival
of stocked smallmouth bass and brown trout; coldwater temperatures ultimately favored
survival of fingerling brown trout.
44

Section 5 Water Quality Assessment and Improvements — Individual Developments
■ Current stocking practices call for annual stocking of fingerling brown trout throughout the
reach and catchable sizes of brook trout, brown trout, and rainbow trout near the
Bridgewater Development. The fish community in the Bridgewater Regulated River
Reach is supported by coldwater releases from the Bridgewater Development and NCWRC
stocking activities.
■ Benthic invertebrate sampling in this reach indicated good populations of
macroinvertebrates. Densities of macroinvertebrates were lower immediately downstream
of the Bridgewater Powerhouse.
■ During summer, the more tolerant forms of dipterans (flies) were prevalent in invertebrate
samples from this reach, although samples were not collected during the period of the
summer when water quality was poorest.
■ Overall bioclassification at Bridgewater was calculated as poor immediately downstream
of the powerhouse but the bioclassification was elevated to Fair -Good at Location 4,
1.8 km downstream of the Bridgewater Development.
■ Mussel surveys of more than 17 hours produced little evidence of freshwater mussels in
this reach. Shells of three specimens and one live specimen of Elliptio complanata and
one Villosa delnmbis shell were collected in this 18 -mile reach. The paucity of mussels in
this reach is expected as a result of coldwater releases from the Bridgewater Powerhouse,
which is consistent with the NCWRC goal of managing this reach of the Catawba River for
trout. Other aquatic invertebrates during these surveys included the Asiatic clam and the
gastropods Elimia proximo, Leptoxis carinata, and Campeloma decisnm.
Bridgewater Bypassed Reaches
Water Quality Findings
The following information was provided in Book 2 of 10, Application for New License
Supplement and Clarification - Study Reports (Duke Energy 2007):
■ There are two bypassed reaches below Lake James. The Catawba River Bypassed Reach
extends from the Catawba Dam to the Linville River. Both Muddy Creek and the Paddy
45

Section 5 Water Quality Assessment and Improvements — Individual Developments
Creek Bypassed Reach, which originates at the base of the Paddy Creek Dam, flow into the
Catawba River Bypassed Reach. These areas currently only partially meet designated
aquatic uses (i.e., flows).
■ Overall, the water quality of the bypassed reaches is good. Concentrations of most
constituents are typical of streams draining the upper Piedmont (i.e., near - saturated DO,
low dissolved solids, metal concentrations at or near the detection limit, and low nutrient
levels).
■ The water quality in the Catawba River Bypassed Reach, downstream of the confluence
with Muddy Creek, exhibited elevated levels of suspended sediment and total phosphorus
originating from Muddy Creek. Increased concentrations of major dissolved solids in the
lower end of this reach suggested groundwater contributions to bypassed flow.
Biological Resource Findings
The following information on the biological resources of the Bridgewater bypassed reaches was
provided in Book 2 of 10, Application for New License Supplement and Clarification - Aquatics
O1 and Aquatics 06 Study Reports (Duke Energy 2007):
■ At present the Catawba River Bypassed Reach contains primarily seepage flows from the
base of the Catawba Dam. This section of stream is characterized by wetland areas and
beaver ponds interspersed with some stream habitat in the approximately 6 miles from the
Catawba Dam to the confluence of Muddy Creek.
■ The fish community in the Catawba River Bypassed Reach was sampled at two locations.
The first location was at the Highway 126 overpass, primarily wetland /stream habitat
influenced by beaver activity. The second area was downstream of the Muddy Creek
confluence but upstream of the Paddy Creek confluence.
■ The species composition of the fish community at the Highway 126 overpass was typical
for the habitat type present in this reach, with 14 fish species and 271 individuals being
collected. Redbreast sunfish and bluegill comprised 66 percent of the total number of
individuals collected. The fish species collected in this reach are rated as tolerant to
intermediate to pollution by the NCDWQ.
46

Section 5 Water Quality Assessment and Improvements — Individual Developments
■ The fish community in the Catawba River Bypassed Reach just downstream of the Muddy
Creels confluence with the Catawba River is diverse consisting of cyprinids (10 species),
catostomids (3 species), ictalurids (2 bullhead species and 1 madtom), centrarchids (5
species) and 3 species of darter. Two of these species, smallmouth bass and Piedmont
darter, are rated as Intolerant of pollution by the NCDWQ.
■ In addition to the fish community discussed above, the Catawba River Bypassed Reach
also provides habitat for several populations of freshwater mussel species: Villosa
delnmbis, Villosa constricta, Elliptio complanata, Elliptio icterina, and ,Strophitns
nndnlatts.
■ An extensive and robust mussel community was observed at the most downstream location
in the Catawba River Bypassed Reach, which consisted primarily of Elliptio complanata,
Elliptio icterina, and Villosa constricta.
■ Mussel surveys downstream of the confluence of Muddy Creels indicated a low density
population of Elliptio complanata.
■ Other aquatic species observed in this area were the gastropod snail, Elimia proximo, and
Asiatic clams (('Orbicnla flnminea).
■ The Paddy Creels Bypassed Reach is characterized by a short section of flowing water,
large areas of standing water, mats of algal growth, and low DO concentration (3.0 mg /1).
■ Beaver impoundments downstream of the sampling reach limited ability for fish
movement. Twelve fish species were collected in this section of Paddy Creels, seven of
which are rated Tolerant of pollution by the NCDWQ. No pollution- Intolerant fish species
were collected in this stream reach.
■ The Paddy Creek Bypassed Reach was marginal in terms of fish habitat. In addition, no
mussels were present in this reach, further indicative of relatively poor stream habitat.
5.1.2 Water Quality Issue Identification and Evaluation
Based upon the findings of the numerous studies conducted for evaluation of the Bridgewater
Development, water quality and resource issues were identified by the stakeholder groups. Even
though the NCDWQ assessment of the Bridgewater Development waters is deemed compatible
with the ascribed designated use (NCDENR 2004), the tailrace and bypassed reaches are not
47

Section 5 Water Quality Assessment and Improvements — Individual Developments
meeting state water quality standards. Therefore, the primary issue regarding water quality is to
protect the water quality where standards were met, and to bring appropriate areas up to state
water quality standards. Additionally, NCDENR (2004) expressed concern that altering historic
flow regimes to accommodate water level management and flows requested by the stakeholders
could result in impairment or degradation of water quality as a result of those proposed
operational changes.
Water quality issues that were raised by NCDENR and /or stakeholders during the Relicensing
process were:
Bridgewater Regulated River Reach
■ Establish higher continuous minimum flow in the Linville - Catawba River channel.
■ Enhance DO concentrations of water released from the powerhouse to meet state standards
(minimum flow and generation flows).
■ Quality and temperature of flows from the bypassed reaches must remain compatible with
trout management objectives once mixed with flow from the Bridgewater Powerhouse.
Bridgewater Bypassed Reaches
■ Establish higher continuous minimum flow in the Catawba River Bypassed Reach.
■ Enhance DO concentrations of water released into the Catawba River Bypassed Reach to
meet state standards.
■ Temperatures from water released into the Catawba River Bypassed Reach must be
compatible with mussel protection and warmwater fish habitat objectives.
5.1.3 Project Modifications for Water Quality Compliance and Resource
Enhancement
Stakeholder negotiations and engineering evaluations have resulted in proposed structural
changes and operational changes, as described below.
48

Section 5 Water Quality Assessment and Improvements — Individual Developments
Proposed Engineering Changes
The Bridgewater Development consists of three earthen dams that must be reinforced to meet
current FERC dam safety specifications. As part of these dam modifications, the current
powerhouse will be removed to make room for the stabilization modifications on the Linville
Dam. A new powerhouse will be built immediately downstream of the current one. Taking
advantage of the new constriction, Duke will install three new turbines in the new powerhouse;
each turbine will be designed to meet the New License requirements for downstream flow and
aeration capability. In addition, modifications made on the Catawba Dam will incorporate a
fixed cone valve to release new continuous minimum flow requirements into the Catawba River
Bypassed Reach. The depth of the intake of this minimum flow device was selected in order to
access water of a suitable temperature to optimize fish and mussel habitat in the bypassed reach.
The combination of temperature and flow rate was selected to minimize the impact to trout
habitat at the point in the river where the bypass flow release mixes with the flow released from
the powerhouse. A summary of the original, current, and future aeration capabilities is presented
in Table 7.
TABLE 7
SUMMARY OF BRIDGEWATER DEVELOPMENT AERATION CAPABILITIES
OVB = Original Vacuum Breaker - Unimproved original vacuum breaker aeration
EVB = Enhanced Vacuum Breaker - Improved vacuum breaker aeration (modified piping and /or headcover)
HVR = Hub Venting Runner - Central aeration through runner hub (new hub venting runner)
PRH = Peripheral Ring Header - Peripheral aeration via ring header at top of draft tube
CMR = Dedicated continuous minimum flow turbine, valve or modification
FCV = Hooded, fixed cone energy dissipation and aerating valve
49
Bridgewater Development: Aeration Capabilities
Turbine/
Original
Current
Future New Powerhouse
Other Release Point
(as of 12/31/2006)
(from FWQIP)
Bridgewater Unit 1
OVB
EVB
HVR PRH
Bridgewater Unit 2
OVB
EVB
HVR PRH
Bridgewater Unit 3
N/A
N/A
PRH CMR
Catawba Dam Aerating
N/A
N/A
FCV CMR
Valve
OVB = Original Vacuum Breaker - Unimproved original vacuum breaker aeration
EVB = Enhanced Vacuum Breaker - Improved vacuum breaker aeration (modified piping and /or headcover)
HVR = Hub Venting Runner - Central aeration through runner hub (new hub venting runner)
PRH = Peripheral Ring Header - Peripheral aeration via ring header at top of draft tube
CMR = Dedicated continuous minimum flow turbine, valve or modification
FCV = Hooded, fixed cone energy dissipation and aerating valve
49

Section 5 Water Quality Assessment and Improvements — Individual Developments
For additional details, refer to the FWQIP shown in Table 4 of the 401 Water Quality
Certification Application.
Proposed Operational Changes
Reservoir — Lake James
■ Reservoir target elevations will be the same or higher than the current practice.
■ In addition, reservoir elevations will be stabilized for Lake James during the spring fish
spawning season.
TABLE 8
TARGET RESERVOIR ELEVATIONS FOR LAKE JAMES
Elevation (ft) at
start of day
USGS
Datum
Full Pond
= 100
I Existing
Proposed
I Existing
I Proposed
Januan- 1
1,196
1,196
96
96
Febnian- 1
1,194
1,194
94
94
March 1
1,192
1,195
92
95
April 1
1,194
1,196
94
96
May 1
1,196
1,198
96
98
June 1
1,198
1,198
98
98
July 1
1,198
1,198
98
98
August 1
1,198
1,198
98
98
September 1
1,198
1,198
98
98
October 1
1,196
1,198
96
98
November 1
1,196
1,196
96
96
December 1
1,196
1,196
96
96
Bridgewater Regulated River Reach
■ Minimum Continuous Flows — The habitat flows for the Bridgewater Development in the
CRA are based on study results, stakeholder negotiations, and CHEOPS analysis of flow
levels that provided improved aquatic habitat, balanced other water user interests, and
which were at levels that could be sustained over the life of the New License.
50

Section 5 Water Quality Assessment and Improvements — Individual Developments
TABLE 9
CONTINUOUS MINIMUM HABITAT FLOWS (CFS) FOR THE
BRIDGEWATER DEVELOPMENT TAILWATER
Month
New License Minimum
Flows (CRA)
Existing Minimum Flows
Januan-
145
Leakage
Febman-
145
Leakage
March
145
Leakage
April
95
Leakage
May
95
Leakage
June
95
Leakage
July
95
Leakage
August
75
Leakage
September
75
Leakage
October
75
Leakage
November
75
Leakage
December
145
Leakage
Catawba River Bypassed Reach
■ Minimum Continuous Flows — These flows were also selected to avoid raising water
temperatures below the Bridgewater Powerhouse above the range for suitable trout habitat.
TABLE 10
CONTINUOUS MINIMUM HABITAT FLOWS (CFS) FOR THE
BRIDGEWATER DEVELOPMENT CATAWBA RIVER BYPASSED REACH
Month
New License Minimum
Flows (CRA)
Existing Minimum Flows
Januan-
75
Leakage
Febman-
75
Leakage
March
75
Leakage
April
75
Leakage
May
75
Leakage
June
75
Leakage
July
50
Leakage
August
50
Leakage
September
50
Leakage
October
50
Leakage
November
50
Leakage
December
75
Leakage
51

Section 5 Water Quality Assessment and Improvements — Individual Developments
Paddy Creels Bypassed Reach
■ Since no additional flows were required beyond existing leakage flows in the Paddy Creels
Bypassed Reach, mitigation was accepted by the NCDENR for this reach. The mitigation
package for the CRA for North Carolina Developments is described in detail in Section 6
(Flow Mitigation Package) of this SIP.
5.1.4 Reasonable Assurance of Future Compliance and Resource Enhancement
5.1.4.1 Water Quality Compliance - Numeric Standards
Tailrace Dissolved Oxygen
The new turbines for the new Bridgewater Powerhouse will be specified to meet DO standards at
all flows. The specifications will be based on the worst case oxygen deficit of 3.6 mg /l (standard
of 5.0 mg /l minus 1.4 mg /l [worst tailrace DO concentration observed in 10 years] = 3.6 mg /l
deficit). After the turbines are installed, the aeration capability will be tested to confirm that the
specifications for required aeration have been met.
The North Carolina Environmental Management Commission (EMC) recently applied a special
trout designation to the Linville - Catawba River below the Bridgewater Powerhouse. The special
designation begins 0.6 mile upstream of the Catawba - Linville confluence, which is well
downstream of the new powerhouse. Also, the DO standards remain at 5.0 mg /l (daily average)
and 4.0 mg /l (instantaneous). This special designation has no impact on the applicable standards
at the Bridgewater Powerhouse.
Bypassed Reach Dissolved Oxygen
Even though the DO concentrations of the source water withdrawn from the reservoir at
Elevation 1168 ft msl at the Catawba Dam may vary considerably throughout the seasons, the
proposed fixed cone valve releasing the minimum flow to the bypassed reach is designed to
52

Section 5 Water Quality Assessment and Improvements — Individual Developments
"spray" the water from the valve, ensuring maximum exposure of the water to the atmosphere
achieving a near oxygen saturation at all water temperatures.
5.1.4.2 Resource Enhancement - Existing Use Standards
According to the North Carolina Department of Environment and natural Resources — Division
of Water Quality (NCDENR- NCDWQ) Surface Waters and Wetlands Standards (2007)
Standards for Class C Waters and higher classifications, "the haters shall be suitable for aquatic
hfe propagation and maintenance of biological integrity, irildhfe, secondary recreation, and
agriculture. Sources of water quality pollution which preclude any of these uses on either a
short-term or long -term basis shall be considered to be violating a hater quality standard." This
is the applicable "existing use" water quality standard for hydroelectric operations and addresses
the need for any receiving waters to be of suitable quality to provide for appropriate aquatic
communities.
As previously described, the Bridgewater Development is complex, with an impoundment
consisting of two basins separated by a shallow canal, two bypassed reaches, and a regulated
river reach (Figure 12). Negotiations with stakeholders indicated that there we re multiple and
conflicting resource management objectives for the Bridgewater Development. Primarily these
resource enhancement goals included:
■ Trout fishery enhancement (Bridgewater Regulated River Reaches)
■ Warmwater stream and freshwater mussel enhancement (Catawba River Bypassed Reach)
■ Water supply (Bridgewater Regulated River Reach)
The allocation of water resources at the Bridgewater Development was based on water quality,
flow /habitat analyses, operations modeling, and negotiation of releases appropriate for
addressing the above resource enhancement goals. These analyses and negotiations led to the
flows for habitat (Tables 11 and 12).
53

Section 5 Water Quality Assessment and Improvements — Individual Developments
The minimum continuous releases defined in the CRA (Tables 8 and 9) are predicted to provide
the range of monthly habitat gains for the most flow sensitive species or guilds present in the
Bridgewater River Reach. In addition to these significant habitat gains, the CRA provides
mitigation for the Paddy Creels Bypassed Reach (Section 6 [Flow Mitigation Package] of this
SIP) and protection of the municipal water supplies.
54

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Section 5 Water Quality Assessment and Improvements — Individual Developments
5.1.5 Evaluation of Potential Reservoir Impacts Resulting From Altering Historic
Flows
Please refer to Section 7.2 (Assessments of Operational Scenarios).
5.2 Rhodhiss Development
The Rhodhiss Development consists of the following existing facilities: (1) the Rhodhiss Dam
consisting of: (a) a 119.58- foot -long concrete gravity bulkhead, (b) a 800 - foot -long, 72- foot -high
concrete gravity ogee spillway, (c) a 122.08- foot -long concrete gravity bulkhead with an
additional 8- foot -high floodwall, and (d) a 283.92- foot -long rolled fill earth embankment; (2) a
2,724 -acre reservoir with a full pond elevation of 995.1 feet above msl; (3) a powerhouse
integral to the dam, situated between the bulkhead on the left bank and the ogee spillway section,
containing three vertical Francis -type turbines directly connected to three generators, two rated at
12,350 kW, one rated at 8,500 kW for a total installed capacity of 28.4 MW; and (4) other
appurtenances (Figure 13).
5.2.1 Current Status
5.2.1.1 North Carolina DWQ Assessments and Water Quality Standards
NCDENR (2004) classified Lake Rhodhiss as eutrophic, with six of seven water quality
parameters identified as lake stressors (percent saturation DO, algae, chlorophyll a, pH,
sediment, and taste and odor). NCDWQ identified Lakes Rhodhiss, Hickory, and Lookout
Shoals as closely linked watersheds with heavy influence from urban centers and agricultural
activities in the relatively large basins.
57

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 13
RHODHISS DEVELOPMENT
58

Section 5 Water Quality Assessment and Improvements — Individual Developments
Lake Rhodhiss receives heavy sediment and /or nutrient loads from Muddy Creels, Lower Creels,
and the Johns River watersheds. In addition, nutrients from the Morganton and Valdese
wastewater treatment plants discharge directly into the lake. Lenoir's wastewater is received via
Lower Creek. Even though Lake Rhodhiss has an average retention time of 21 days, the highly
variable flows greatly influence the impact of nutrient loading to the lake. At high inflows, algal
blooms were limited by short retention times. Low inflows (high retention times, high light
penetration, and favorable nutrient concentrations) allowed algal blooms to develop and persist.
These higher algal populations have triggered high pH and DO values. In addition, taste and
odor problems, originating from some algal blooms, have increased the cost associated with
treating drinking water supplies. These observations have led the NCDWQ to classify Lake
Rhodhiss as impaired for aquatic life.
NCDWQ has identified and encourages many local initiatives designed to address the water
quality impairment of Lake Rhodhiss, such as controlling nutrient inputs.
All waters in the Rhodhiss basin are fully supporting for recreational and drinking water use,
with some headwater streams designated as High Quality Waters and /or Outstanding Resource
Waters. In addition to Lake Rhodhiss, 39.7 miles of tributaries to the lake (excluding Muddy
Creek drainage discussed with the Bridgewater tailrace) were considered impaired for aquatic
life.
Impaired waters inside the Project boundaries:
■ 1,848.5 acres of Lake Rhodhiss: biological impairment, excess sediment, and nutrients
Impaired waters outside the Rhodhiss Project boundaries that potentially influence water quality
within the Rhodhiss Development include:
■ 303(d) listings for inflows to Lake Rhodhiss were:
— 7.4 miles of Hunting Creek: biological impairment
59

Section 5 Water Quality Assessment and Improvements — Individual Developments
— 3.0 miles of Irish Creek (Warrior Fork): biological impairment, poor instream and
riparian habitats
— 25.4 miles of Lower Creek (including tributaries): biological impairment, poor land
use practices /sedimentation
— 3.9 miles of McGalliard Creek: biological impairment, lack of riparian vegetation in
residential area
5.2.1.2 FERC Relicensing Data Summary
Reservoir - Lake Rhodhiss
Water Quality Findings
The following information was provided in Book 2 of 10, Application for New License
Supplement and Clarification - Study Reports (Duke Energy 2007):
• Lake Rhodhiss has a short retention time (21 days on average). With minimum storage
capability, Lake Rhodhiss is dynamic and, at most times, inflow driven.
• Overall water quality in Lake Rhodhiss is nutrient rich and the reservoir is rated by
NCDWQ as impaired (high pH).
• Duke operates the Rhodhiss Development for peaking energy or to maintain target lake
levels.
• Currently, Units 1 and 2 have stay vane aeration capability.
• Phosphorus contributions due to point source and non -point discharges are not fully
processed before being released from the dam.
• Phosphorus patterns are very dynamic, and are driven by loadings that get diluted and
redistributed by intermittent reservoir flow.
• Low DO occurs due to sediment oxygen demand along the bottom where residence times
are longer, and in the middle reservoir depths due to algal respiration.
60

Section 5 Water Quality Assessment and Improvements — Individual Developments
■ Low flow periods (i.e., long retention time), coupled with less diluted nutrient
concentrations, produce the lowest DO levels within the reservoir and, subsequently,
released from the reservoir.
Biological Resource Findings
The following information on the biological resources of Lake Rhodhiss was provided in Book 2
of 10, Application for New License Supplement and Clarification - Aquatics 01 Study Report
(Duke Energy 2007):
■ Twenty -eight species of fish, plus hybrid sunfish, were observed during spring
electrofishing (1994 -1997 and 2000). Biomass estimates averaged 174.4 kg per kilometer
of shoreline, while density averaged 903 fish per kilometer.
■ Biomass was dominated by largemouth bass and common carp, which averaged 40 percent
and 31 percent of total biomass, respectively. Sunfish (primarily bluegill and redbreast)
accounted for an average of 10 percent of total biomass, and white catfish for 8 percent.
■ In terms of density, bluegill was the dominant species (39 percent), followed by redbreast
sunfish (21 percent), largemouth bass (16 percent), and yellow perch (10 percent).
■ Hydroacoustic (1997 and 2000) and purse seine sampling (1993 -1997 and 2000) indicated
that limnetic densities of forage fish in Lake Rhodhiss averaged 24,172 fish per hectare.
■ Gizzard shad was a highly variable component of limnetic species composition,
comprising from 0.3 to 100 percent of the total and averaging 56 percent. Threadfin shad
averaged 44 percent of pelagic fish density. The composition of the forage fish community
was potentially affected by thermal stress to threadfin shad during severe winters, and by
stocking of threadfin by the NCWRC.
■ No fish kills on Lake Rhodhiss were reported by the NCWRC from 1988 through July
2001; however, winter die -offs of threadfin shad may be expected since winter water
temperatures on Lake Rhodhiss averaged 6 °C, which is below the thermal tolerance limit
for threadfin shad.
61

Section 5 Water Quality Assessment and Improvements — Individual Developments
Tailrace — Rhodhiss
Water Quality Findings
The following information was provided in Book 2 of 10, Application for New License
Supplement and Clarification - Study Reports (Duke Energy 2007):
■ Rhodhiss releases directly into Lake Hickory.
■ Ten years of tailrace continuous monitoring at approximately 5- minute intervals for
temperature, pH, and DO revealed that only DO did not consistently meet state water
quality standards in turbine releases.
■ On the average, during May through November, 13 percent of the hourly average DO
concentrations released from the Rhodhiss Development are lower than the current
instantaneous state standard of 4.0 mg /1.
■ On the average, during May through November, 38 percent of the daily average DO
concentrations released from the Rhodhiss Development are lower than the current state
standard of 5.0 mg /l daily average.
■ Measured 4 -year (1997 -2000) average nutrient concentrations for Bridgewater releases
and Rhodhiss releases:
— Total Phosphorus: 10 mg /l for Bridgewater and 46 mg /l for Rhodhiss
— Dissolved Organic Carbon: 13 mg /l for Bridgewater and 1.9 mg /l for Rhodhiss
— Particulate Organic Matter: 0.4 mg /l for Bridgewater and 2.7 mg /l for Rhodhiss
5.2.2 Water Quality Issue Identification and Evaluation
Rhodhiss Tailrace
■ Enhance DO concentrations to meet state standards in the water used for electrical
generation and released downstream.
62

Section 5 Water Quality Assessment and Improvements — Individual Developments
5.2.3 Project Modifications for Water Quality Compliance and Resource
Enhancement
Stakeholder negotiations and engineering evaluations have resulted in proposed structural
changes and operational changes, as described below.
Proposed Engineering Changes
TABLE 13
SUMMARY OF RHODHISS DEVELOPMENT AERATION CAPABILITIES
Turbine /
Other Release Point
Original
Current
(as of 12/31/2006)
Future
(from FWQIP)
Rhodhiss Unit 1
OVB
HSV
HSV
Rhodhiss Unit 2
OVB
HSV
HSV
Rhodhiss Unit 3
OVB
OVB
AVR
OVB = Original Vacuum Breaker - Unimproved original vacuum breaker aeration
EVB = Enhanced Vacuum Breaker - Improved vacuum breaker aeration (modified piping and /or headcover)
HSV = Hollow Stay Vane - Aeration through existing hollow stay vanes
AVR = Auto Venting Ruiner - Auto venting type turbine aeration (new auto venting ruiner)
For additional details, refer to the FWQIP shown in Table 4 of the 401 Water Quality
Certification Application.
Proposed Operational Changes
Reservoir — Lake Rhodhiss
■ Reservoir elevations in the CRA match current practice and are consistent throughout the
year.
63

Section 5 Water Quality Assessment and Improvements — Individual Developments
TABLE 14
TARGET RESERVOIR ELEVATIONS FOR LAKE RHODHISS
Elevation (ft) at
start of day
USGS Datum
Full Pond = 100
Existing
Proposed
Existing
Proposed
Januan- 1
992.1
992.1
97
97
Febman- 1
992.1
992.1
97
97
March 1
992.1
992.1
97
97
April
992.1
992.1
97
97
May 1
992.1
992.1
97
97
June 1
992.1
992.1
97
97
J111v 1
992.1
992.1
97
97
August 1
992.1
992.1
97
97
September 1
992.1
992.1
97
97
October 1
992.1
992.1
97
97
November 1
992.1
992.1
97
97
December 1
992.1
1992.1
197
97
■ One unit at the Rhodhiss Development is run at efficiency load at least once each day,
generating approximately 21 MWh to meet the MADF license requirement of 225 cfs.
5.2.4 Reasonable Assurance of Future Compliance and Resource Enhancement
5.2.4.1 Dissolved Oxygen - Numeric Standards
The use of turbine venting at the Rhodhiss Development was evaluated by developing a DBM
(Appendix B) for the future turbine aeration capabilities proposed at Rhodhiss. The station will
have two existing turbines with hollow stay vane venting and one new turbine with an
autoventing runner. The DBM was calibrated in 2006 for both of the HSV Rhodhiss turbines.
The field calibration test collected the following measurements at various unit power levels:
airflow, water flow, initial DO flowing to the turbine, temperature, and DO uptake. A DBM was
developed for the future AVR unit by extrapolating data from other AVR unit specifications and
the existing Rhodhiss turbine and draft tube design.
64

Section 5 Water Quality Assessment and Improvements — Individual Developments
The calibrated DBM for each turbine was used as a tool to predict the DO uptake of existing and
future turbine upgrades by solving the calibrated equation for each historical hourly flow,
temperature, and DO concentration. These hourly values were calculated from historical water
quality measurements made in the Rhodhiss tailrace at 5- minute intervals.
All predicted DO uptakes resulting from the calibrated DBM equation were compared to the
actual historical monitoring data and to state standards for instantaneous DO concentration (4.0
mg /1) and daily average DO concentration (5.0 mg /1) (Figures 14 through 17). The use of the
DBM to predict future tailrace DO concentrations illustrated that the proposed turbine
configuration (2 HSV and 1 AVR units) will meet state DO standards at all flows and inflowing
DO concentrations.
65

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 14
FREQUENCY OF COMPLIANCE WITH INSTANTANEOUS DISSOLVED OXYGEN
STATE WATER QUALITY STANDARDS (4.0 MG/L) FOR HOURLY DISSOLVED
OXYGEN CONCENTRATIONS AT RHODHISS CALCULATED FROM DISCRETE
BUBBLE MODEL IN COMPARISON TO THE HISTORICAL RECORD
12
10
1— 8
O
Cz
,�z 6
U
O
R
0 4
Q
2
0
Rhodhiss
Total Number of Hours = 24,242
�,a
mnm„
Instantaneous DO
standard
- - - --
Hourlv with aeration
------ ',------- ',-------
',------- ------- ',------
Hourly without aeration
0 10 20 30 40 50 60 70
Frequency Exceeding DO Concentration ( %)
66
80 90 100

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 15
COMPARISON OF HOURS OF NON - COMPLIANCE AT RHODHISS TO
INSTANTANEOUS DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS
(4.0 MG/L) CALCULATED FROM DISCRETE BUBBLE MODEL AND THE
HISTORICAL RECORD
10,000
1,000
0
100
w
0
Z
10
1
0
Rhodhiss
Total Number of Hours = 24,242
- - - Instantaneous DO standard - - - - -
Hourly with aeration - _ _ _
----------------+---- -- +- - - - - --
--- ------------- ----- ----- - - - - --
--------------------- ----- - - - - --
-------- 1----- - - -L -- ----- L - - - - - --
------------ --- ;--------
- -------
-------- L-- - - - - -_ __ -- - - - - - --
-- - - - - -- - - - - - - - - - - - - - - - - - - -
- -----
-------- --------------------------
-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- --
-- - - - - - - -- - - - - - -
-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1 2 ; 4 5 6 7 8
DO Concentration (mg /1)
67

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 16
FREQUENCY OF COMPLIANCE WITH DAILY AVERAGE DISSOLVED OXYGEN
STATE WATER QUALITY STANDARDS (5.0 MG/L) FOR DAILY AVERAGE
DISSOLVED OXYGEN CONCENTRATIONS AT RHODHISS CALCULATED FROM
DISCRETE BUBBLE MODEL IN COMPARISON TO THE HISTORICAL RECORD
12
10
--1 K
O
,�z 6
U
U
O
U
Q 4
2
0 -
Rhodhiss
Total Number of Days = 2567
---------------------------- - ------------------- - - - - - - i - - - - --
°wm
Daily average DO standard
Daily with ith aeration - -
� '� I
Daily average without aeration
0 10 20 30 40 50 60 70 80
Frequency Exceeding DO Concentration ( %)
68
90 100

Section 5 Water Quality Assessment and Improvements - Individual Developments
FIGURE 17
COMPARISON OF DAYS OF NON - COMPLIANCE AT RHODHISS TO DAILY
AVERAGE DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (5.0
MG/L) CALCULATED FROM DISCRETE BUBBLE MODEL AND THE HISTORICAL
0
U
H
W
0
9
z
L�
M
Rhodhiss
Total Number of Days = 2567
-- - - - - - - J -------- J - - - - -- L ------------- - - - -', u =---=-- - - - - --
— — — —I— — — — — — — — J — — — — — — — — { — — — — — — — — L — — — — — — — —'— — — — — — — ,.1 — — — — — — — 1 — — — — — — — -
- — — — — — —I— — — — — — — — J — — — — — — — — 1 — — — — — — — — L — — — — — — — —'— —n.,— —I— — — — — — — 1 — — — — — — — —
DailN- average DO standard
-
Dai1N- average without aeration - -- r - - � ' _ _ _ _ _ _ _ _ - - - - - - - -
— DailN- average with aeration
---------------- +-------- + - - - -' - +------- - - - - -- ---I--------+--------
{ — — — — r — — — — — — — — — — — — — —I— — — — — — — — _T — — — — — —
— — — — — — — — — { — — — — — r — — — — — — — — — — — — — —I— — — — — — — — T — —
— — — — — — — + — — — — — — — — + — — — — { — — — — — — — — — — — — — —I— — — — — — — — + — — — — — — — —
— — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — —
I I I I I
— — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — —
I I I I I
I I I I I
— — — — — — —I— — — — — — — — J — — — — — — { — — — — — — — — L — — — — — — — — — — — — —I— — — — — — — — J — — — — — — —
I I I I I I
I I I I I I
I I I I I I
— — — — — — — — — — — — — — — —I— — — — — — — — -
- — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — —. — — — — — — — — — — — — — — — — — — — — — — — — —
— — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — -
- — — — — — —,— — — — — — — — —, — — — — — — — { — — — — — — — — j — — — — — — — — — — — — — — — —,— — — — — — — — — — — — — — -
- — — — — — — — — — — — — — — — — — — { — — — — — — — — — — — — — — — — — — — — — —I— — — — — — — —
— — — — — — _,_ — — — — — — — + — - — — — — — — + — — — — — — — — { — — — — — — — — — — — — — — —I— — — — — — — — + — — — — — — — —
I I I I I I
I �
() 1 2 ; 4 5 6
DO Concentration (mg /1)
5.2.4.2 Resource Enhancement - Existing Use Standards
7 8
According to the NCDENR -NCDWQ Surface Waters and Wetlands Standards (2007) Standards
for Class C Waters and higher classifications, "the haters shall be suitable for aquatic life
propagation and maintenance of biological integrity, lvildh/e, secondary recreation, and
agriculture. Sources of water quality pollution which preclude any of these uses on either a
short-term or long -term basis shall be considered to be violating a hater quality standard." This
is the applicable "existing use" water quality standard for hydroelectric operations and addresses
69

Section 5 Water Quality Assessment and Improvements — Individual Developments
the need for any receiving waters to be of suitable quality to provide for appropriate aquatic
communities.
At "lake -to- lake" tailraces ( Rhodhiss, Cowans Ford, Mountain Island, Fishing Creels, Great
Falls /Dearborn, and Rocky Creek/Cedar Creek), the downstream reservoir backs up into the
powerhouse tailrace. At these lake -to -lake locations, the tailwater character will remain
lacustrine in nature and would not reasonably be expected to change in nature under minimum
continuous flows that are more appropriately intended to enhance riverine aquatic habitat.
However, the reservoir headwater in the vicinity of the hydro tailrace may benefit from DO
enhancements.
Based on known aquatic resources and the anticipated improvements in aquatic habitat and DO
levels in the Rhodhiss tailrace, which are anticipated as a result of a New License consistent with
applicable sections of the CRA, the Rhodhiss Development will comply with the NCDWQ
existing use water quality standard.
5.2.5 Evaluation of Potential Reservoir Impacts Resulting from Altering Historic
Flows
Please refer to Section 7.2 (Assessments of Operational Scenarios).
5.3 Oxford Development
The Oxford Development consists of the following existing facilities: (1) the Oxford Dam
consisting of: (a) a 74.75- foot -long soil nail wall, (b) a 193 - foot -long emergency spillway, (c) a
550- foot -long gated concrete gravity spillway, (d) a 112 - foot -long embankment wall situated
above the powerhouse, and (e) a 429.25- foot -long earth embankment; (2) a 4,072 -acre reservoir
with a full pond elevation of 935 feet above msl; (4) a powerhouse integral to the dam, situated
between the gated spillway and the earth embankment, containing two vertical Francis -type
turbines directly connected to two generators, each rated at 18,000 kW for a total installed
capacity of 35.7 MW; and (5) other appurtenances (Figure 18).
70

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 18
OXFORD DEVELOPMENT
!
Sch
Al
If
A,
k ' a v
tfi
�tr�r ki� -P'
{ `bM ' t
!�4
W
4Ir n .,-
f Al
J�+ I !!�}�� ¢4tn�
y �hy Ili `1,
t 7 1 yt �9 4
! iA+' n - F , , ,} u,v t` 4 !. V 1 „t ! 4•
tY !
t �. ! ! 1 1 t r uxro+B i'� SEl��.9 "�t�2C
Le �tl.Il�� �I €
�y�,
River
�i i�'" � ! � oxford `v k; ! � byo- r �,,,�°�"�.� � � "°✓ a"
imp
_
!
Oxford Tairace r
,
h Dxfford
Powerhouse !}� � „�.. ;y� tl ! S ��I v � �� , �'i + `.t ,1,7`�
S
r� 4 !
i v P �"w h h ! '�
i
5 s
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if
I
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t, 1 4
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r . ��` '✓ =m -,m v- �, —4, f 'P
ml
}t
"w"
FA ¢
ts.
r !
r
Oxford Development
Catawba-Wateree Project
FERC NO. '_
arc!'.
71

Section 5 Water Quality Assessment and Improvements — Individual Developments
5.3.1 Current Status
53.1.1 North Carolina DWQ Assessments and Water Quality Standards
NCDENR (2004) classified Lake Hickory as meso - eutrophic, with six of seven water quality
parameters identified as lake stressors (non -point source pollution, percent saturation DO, algae,
sediment, and taste and odor). NCDWQ identified Lakes Rhodhiss, Hickory, and Lookout
Shoals as closely linked watersheds with heavy influence from urban centers and agricultural
activities in the relatively large basins.
Lake Hickory is endangered of becoming eutrophic (impaired). Periodic algal blooms have
caused elevated DO saturation levels, pH, and chlorophyll a. Taste and odor problems have been
noted. The close linkage between Lakes Rhodhiss and Hickory is most pronounced in the
majority of the nutrients received by Lake Hickory originating from Lake Rhodhiss. Lake
Hickory is more sensitive to water quality conditions in Lake Rhodhiss than in its own
immediate drainage basin. However, computer modeling by the U.S. Geological Survey (Bales
and Giorgino 1998) indicated that the lake is not immune from urban runoff in localized streams.
As with Lake Rhodhiss, NCDWQ continues to encourage local initiatives designed to address
the water quality issues in the Rhodhiss /Hickory/Lookout Shoals chain.
All waters in the Lake Hickory basin are fully supporting recreational and drinking water use. A
total of 14.5 miles of tributaries to the lake were considered impaired to aquatic life. All waters
inside the Hickory Project boundaries were considered fully supporting the use classification.
Impaired waters outside the Hickory Project boundaries that potentially influence water quality
within the Oxford Development include:
■ 303(d) listings for inflows to Lake Hickory were:
— 1.1 miles of Horseford Creek: biological impairment
72

Section 5 Water Quality Assessment and Improvements — Individual Developments
5.3.1.2 FERC Relicensing Data Summary
Reservoir - Lake Hickory
Water Quality Findings
The following information was provided in Book 2 of 10, Application for New License
Supplement and Clarification - Study Reports (Duke Energy 2007):
■ Overall, according to NCDWQ water quality is poor due to nutrient levels.
■ Duke Energy operates the Oxford Development for peaking energy or to maintain target
lake levels.
■ Lake Hickory receives elevated levels of phosphorus from several primary sources: Lake
Rhodhiss releases and five point sources discharge directly to the lake. The highest levels
of phosphorus from Rhodhiss occur during the months from January through March,
increasing the phosphorus levels in Lake Hickory just before the spring growing season.
■ Lake Hickory traps a significant amount of phosphorus.
Biological Resource Findings
The following information on the biological resources of Lake Hickory was provided in Book 2
of 10, Application for New License Supplement and Clarification - Aquatics 01 Study Reports
(Duke Energy 2007):
■ Twenty -nine species of fish, plus hybrid sunfish, were observed during spring
electrofishing (1994 -1997 and 2000). Two areas within the lake were sampled: uplake
and downlake in the vicinity of the forebay. Littoral fish biomass averaged 10 1. 1 kg /km
uplake and 94.4 kg /km downlake.
■ Littoral fish biomass was dominated by largemouth bass, common carp, and white catfish
in both areas of Lake Hickory. Numerically, bluegill and redbreast sunfish were the
73

Section 5 Water Quality Assessment and Improvements — Individual Developments
dominant species in fish the community; sunfish accounted for 54 percent of total fish
density uplake and 70 percent of total fish density downlake.
■ Hydroacoustic (1997 and 2000) and purse seine sampling (1993 -1997 and 2000) indicated
that limnetic densities of forage fish in Lake Hickory averaged 30,438 fish per hectare in
1997 and 11,173 fish per hectare in 2000.
■ The vulnerability of threadfin shad to thermal stress during severe winters was reflected in
the extreme variability among years in the composition of the forage fish community.
■ Gizzard shad comprised nearly 100 percent of fish in purse seine samples in 1994, 1995,
and 1996, while threadfin shad accounted for nearly 100 percent in 1993, 1997, and 2000.
■ One fish kill was reported in the Lake Hickory watershed from 1988 through July 2001.
Mortality of 250 yellow perch and catfish was observed in the forebay of Lake Hickory in
July 2001. No cause was apparent.
■ As with Lakes James and Rhodhiss, it is likely that winter die -offs of threadfin shad
occurred regularly, as winter surface temperatures averaged 6.7 °C, below tolerance limits
for threadfin shad.
Oxford Regulated River Reach
Water Quality Findings
The following information was provided in Book 2 of 10, Application for New License
Supplement and Clarification - Study Reports (Duke Energy 2007):
■ Ten years of tailrace continuous monitoring at approximately 5- minute intervals for
temperature, pH, and DO revealed that only DO did not meet state water quality standards
for turbine releases.
■ On the average, during May through November, 29 percent of the hourly average DO
concentrations released from Oxford Development exceed the current state standard of 4.0
mg /l instantaneous.
74

Section 5 Water Quality Assessment and Improvements — Individual Developments
■ On the average, during May through November, 43 percent of the daily average DO
concentrations released from Oxford Development exceed the current state standard of 5.0
mg /l daily average.
■ Actual average nutrient Rhodhiss releases compared to Oxford releases:
— Total Phosphorus: 46 mg /l for Rhodhiss and 22 mg /l for Oxford
— Dissolved Organic Carbon: 1.9 mg /l for both Rhodhiss and Oxford
— Particulate Organic Matter: 2.7 mg /1 for Rhodhiss and 1.1 mg /1 for Oxford
■ Temperature and DO are very dynamic in the 3 -mile tailwater between Oxford Dam and
the headwater of Lookout Shoals Lake.
— Temperature and DO both increase rapidly at all locations in the tailwater during
mid -day in summer if there is no generation. This occurs due to shallow depths and
extensive aquatic vegetation.
— During generation, fluctuations in temperature and DO are reduced in amplitude.
Biological Resource Findings
The following information on the biological resources of the Oxford Regulated River Reach was
provided in Book 2 of 10, Application for New License Supplement and Clarification - Aquatics
O1, Aquatics 06, and Aquatics 07 Study Reports (Duke Energy 2007):
■ The fish community in the Oxford Regulated River Reach was sampled at three locations.
The first location was at the immediate tailrace of the dam (RM 229.9, west of Hwy 16),
and was primarily shoal habitat. The second area was 1.4 RM downstream of the Oxford
Dam (RM 228.5), and the third location was 3 miles downstream of the Oxford Dam (RM
226.9, in the vicinity of the Island Creek confluence where the river makes a bend to the
south).
■ The species composition of the fish community at the Oxford Tailrace (RM 229.9) was
typical for the habitat type present in this reach, with 13 fish species and 483 individuals
being collected over the two sampling periods. Redbreast sunfish and bluegill comprised
67 percent of the total number of individuals collected in the spring sampling period and
60 percent of the total number of individuals collected in the summer sampling period.
75

Section 5 Water Quality Assessment and Improvements — Individual Developments
The fish species collected in this reach are rated as Intermediate to Tolerant of pollution by
the NCDWQ.
■ Species composition of the fish community at the middle station (RM 228.5) was typical
for the habitat type present in this reach, with 13 fish species and 224 individuals being
collected over the two sampling periods. Redbreast sunfish and bluegill comprised 60
percent of the total number of individuals collected in the spring sampling period, and
redbreast sunfish and largemouth bass comprised 51 percent of the total number of
individuals collected in the summer sampling period. The fish species collected in this
location are rated as Intermediate to Tolerant of pollution by the NCDWQ.
■ The species composition of the fish community at the lower station (RM 226.9) was
typical for the habitat type present in this reach, with 20 fish species and 826 individuals
being collected over the two sampling periods. Redbreast sunfish and largemouth bass
comprised 62 percent of the total number of individuals collected in the spring sampling
period, and spottail shiner and largemouth bass comprised 71 percent of the total number
of individuals collected in the summer sampling period. The fish species collected in this
location are rated as Intermediate to Tolerant of pollution by the NCDWQ.
■ Benthic invertebrate sampling in this reach indicated good populations of
macroinvertebrates. The mean density of all organisms in the samples collected
downstream of Oxford Dam in the spring was slightly higher at Location 1 (immediately
downstream of Oxford Dam) than at Location 3 (3.2 kilometers downstream of Oxford
Dam). The proportion of ephemeroptera (mayfly), plecoptera (stonefly), and trichopetera
(caddisfly) (EPT) taxa decreased from Location 1 to Location 3 in the spring, but increased
from Location 1 to Location 3 in the summer. Overall bioclassification at Oxford was
calculated as fair immediately downstream of the Powerhouse as well as at Location 3
although the Biotic Index Score (an indicator of water quality) was slightly higher at
Location 3. There were three more EPT taxa collected at the downstream location, and the
macroinvertebrate community was somewhat less tolerant than near the dam.
■ In addition to the fish community discussed above, the Oxford Tailrace and Oxford
Regulated River Reach also provide habitat for populations of the freshwater mussel
species: Uniomerns sp. and -1vganodon cataracts. Other mussel species observed in this
area include Asiatic clams.
76

Section 5 Water Quality Assessment and Improvements — Individual Developments
■ Crayfish were also collected from this area incidental to other survey activities. The
crayfish species collected in this location includes Orconectes (Gremicambarns) virilis, an
exotic species, and Cambarns (('ambarns) bartonii.
5.3.2 Water Quality Issue Identification and Evaluation
Even though the NCDWQ assessment of the Oxford Development waters is deemed compatible
with the ascribed designated use, releases from the Oxford Powerhouse and into the regulated
river reach downstream were not meeting water quality standards. Therefore, the primary issue
dealing with water quality is to protect the water quality where standards were met, and to bring
appropriate areas up to state water quality standards.
Oxford Regulated River Reach
■ Establish higher minimum flow in the Catawba River channel.
■ Enhance DO concentrations in the water released from powerhouse to meet state standards
(minimum flow and generation flows).
5.3.3 Project Modifications for Water Quality Compliance and Resource
Enhancement
Stakeholder negotiations and engineering evaluations have resulted in proposed structural
changes and operational changes, as described below.
77

Section 5 Water Quality Assessment and Improvements — Individual Developments
Proposed Engineering Changes
TABLE 15
SUMMARY OF OXFORD DEVELOPMENT AERATION CAPABILITIES
Turbine/
Other Release Point
Original
Current
(as of 12/31/2006)
Future
(from FWQIP)
Oxford Unit 1
OVB
HVR
HVR
Oxford Unit 2
OVB
HVR
AVR
Oxford Dam Aerating
Valve
N/A
N/A
FCV CMR
OVB = Original Vacuum Breaker - Unimproved original vacuum breaker aeration
HVR = Hub Venting Ruiner - Central aeration through itumer hub (new hub venting itumer)
AVR = Auto Venting Ruiner - Auto venting type turbine aeration (new auto venting itumer)
CMR = Dedicated continuous minimum flow turbine, valve or modification
FCV = Hooded, fixed cone energy dissipation and aerating valve
For additional details, refer to the FWQIP shown in Table 4 of the 401 Water Quality
Certification Application.
Proposed Operational Changes
Reservoir — Lake Hickory
TABLE 16
TARGET RESERVOIR ELEVATIONS FOR LAKE HICKORY
Elevation (ft) at
start of day
USGS Datum
Full Pond = 100
Existing
Proposed
Existing
Proposed
Januan- 1
932
931
97
96
Febman- 1
932
931
97
96
March 1
932
932
97
97
April
932
932
97
97
May 1
932
932
97
97
June 1
932
932
97
97
JuIv 1
932
932
97
97
August 1
932
932
97
97
September 1
932
932
97
97
October 1
932
932
97
97
November 1
932
932
97
97
December 1
932
932
97
97
78

Section 5 Water Quality Assessment and Improvements — Individual Developments
Oxford Regulated River Reach
■ Minimum Continuous Flows - The habitat flows for the Project in the CRA are based on
study results, stakeholder negotiations, and CHEOPS analysis of flow levels that provided
improved aquatic habitat, balanced other water user interests, and which were at levels that
could be sustained over the life of the New License.
TABLE 17
CONTINUOUS MINIMUM HABITAT FLOWS (CFS) FOR THE
OXFORD DEVELOPMENT TAILWATER
Month
New License Minimum
Flows (CRA)
Existing Minimum Flows
January-
150
Leakage
February-
150
Leakage
March
150
Leakage
April
150
Leakage
May
150
Leakage
June
150
Leakage
July
150
Leakage
August
150
Leakage
September
150
Leakage
October
150
Leakage
November
150
Leakage
December
150
Leakage
■ A valve will be installed at the Oxford Powerhouse that will provide 150 cfs continuous
minimum flow to the Oxford Regulated River Reach. Even though these flows do not
fully meet resource agency habitat goals, there are gains in aquatic habitat. Mitigation will
be provided as described in Section 6 (Flow Mitigation Package) of this SIP since the
habitat gains do not fully meet state resource agency goals.
■ Beginning within 60 days following the date of closure of the New License, raise a
floodgate during periods of no generation to release and aerate the Minimum Continuous
Flow.
79

Section 5 Water Quality Assessment and Improvements — Individual Developments
5.3.4 Reasonable Assurance of Future Compliance and Resource Enhancement
53.4.1 Dissolved Oxygen - Numeric Standards
The applicability of turbine venting at the Oxford Development was evaluated by developing a
DBM (Appendix B) for each future turbine configuration (Oxford = one HVR unit and one AVR
unit). In addition, modifications made on one of the floodgates will incorporate a fixed cone
valve to release the minimum flow requirements downstream of Oxford Hydro. The fixed cone
valve will release 150 cfs and the water will be sprayed into the atmosphere and become nearly
100 percent saturated with DO. This minimum flow was not used in the hourly and daily
calculations for future Oxford tailrace DO predictions.
The DBM was calibrated in 2006 for one HVR Oxford turbine. The field calibration test
included the following measurements at various unit power levels: air flow, water flow, initial
DO flowing to the turbine, temperature, and DO uptake. A DBM was determined for the future
AVR unit by extrapolating data from other AVR unit specifications and the Oxford draft tube
geometry.
The calibrated DBM for each turbine was used as a tool to predict the DO uptake of existing and
future turbine upgrades by solving the calibrated equation with each historical hourly flows
(generation flows were adjusted to compensate for the future license requirement of 150 cfs
minimum flow), temperatures, and DO concentrations. These historical mean hourly values
were calculated from the period of record of water quality measurements made in the Oxford
tailrace at 5- minute intervals.
All predicted DO uptakes resulting from the calibrated DBM equation were compared to the
actual historical monitoring data and to state standards for instantaneous DO concentration (4.0
mg /1) and daily average DO concentration (5.0 mg /1) (Figures 19 through 22). The use of the
DBM to predict future tailrace DO concentrations illustrated that the proposed turbine
configuration (1 HSV and 1 AVR unit) will meet state DO standards at all flows and inflowing
a

Section 5 Water Quality Assessment and Improvements — Individual Developments
DO concentrations. Both the instantaneous 4.0 mg /1 and daily average of 5.0 mg /1 should be
realized in the future.
FIGURE 19
FREQUENCY OF COMPLIANCE WITH INSTANTANEOUS DISSOLVED OXYGEN
STATE WATER QUALITY STANDARDS (4.0 MG/L) FOR HOURLY DISSOLVED
OXYGEN CONCENTRATIONS AT OXFORD CALCULATED FROM DISCRETE
12
I
0
ro
V
/O
I--I
BUBBLE MODEL IN COMPARISON TO THE HISTORICAL RECORD
Oxford
Total Number of Hours = 12,240
I I I I I I I I I
---- - -, - -- - - ---- - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - r - - - - --
I I `� i... I I I I I I
I I I I I I I I
I I I I I I
- - - -- - - - - - - - - - - - - - - - - - - - - - - - - ,, - - - -- - --
I I I I I I I I I
r Instantaneous DO standard
e,
- - Hourly with aeration - - -
I I I I I
Hourly without aeration
I I I I I
I I I I I I I I I
I I I I I I I I I
10 20 30 40 50 60 70 80
Frequency Exceeding DO Concentration ( %)
81
90 100

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 20
COMPARISON OF HOURS OF NON - COMPLIANCE WITH INSTANTANEOUS
DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (4.0 MG/L)
CALCULATED FROM DISCRETE BUBBLE MODEL AND THE HISTORICAL
1,000
FF��0-I
3—i
100
10
Oxford
Total Number of Hours = 12,240
- - - - - - - - - - - - - - - t - - - - - - - -I- - - - - - - - - - - - - - - - t - - - - - - - -I- - - - - - - - Y - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
- - - - - - -I-------- L - - - - - - - -I- - - - - - - - - - - - - - - - L - - - - - - - -I- - - - - - - - L - - - -
i <.
--- - - - - -- t ----------- - - - - -- --- - - - - -t --- ,�,Lw�,w?w_ _ _ - - -- —'- - - - - - --
-- - - - - - - - - - - - - - - t - - - - - - - - - - - -- - - -n�,• --- - - - - - - - - - - - wwY - - - - - - - -
I
nib" I
}_ - - _�- - - - - - - -} - - - - -- -I - - - - - - - } -- - - - - --
L - ,y I- - - - - - - - - - - L - - - - - - L - - - - - - L
- - - - - - -I- - - - - - - - t - - -` n�- - -I- - - - - - - - - - - - - - - - t - - - - - -I- - - - - - - - t - - - - - - - -
- - - - - - - - - - - - ± - - - - - - - - - - - - - - - - ~ - - - - - - - - - - - + - - - - - -
I I I I I I
I I I I I
I I I I
I I I I I
- - - - - _ _ - -- _ 1_ -- -_I- - _ _ _ _ -_I -_ L_ _
L- - - - - - -I- - - - - - - - - - - - - - - - - -I- - - - - - - - L - - - - - - -
t - - - - - - - -I- - - - - - - - - - - - - - - - - - - - - - - -I- - - - - -
-
--------------- -- - ------------
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
I_ I- - - - - - - - - - - - - - - - - - - - -I T
- - - - - - -I- - - - - L - - - - - - - -I- - - - - - - - - - - - - - - - - - - - -I- - - - - - - - L - - - - - - -
I I I I I
I I I I I
I I I
___ ____ ______�__ - - - L' - -- - - _ - -- - - Instantaneous DO standard =
- --------------- t -------- I ----------- - - - - -- -
--------------------------------------------- -
- - - - -' - -- - - - - -- -- Hourly without aeration
-- - - - - - -
- ------ t------------------- - - - - -- -
-- - - - - - -�I - -------- - - - - - - - - - -- - - - - -- Hourly with aeration
I I I I I
DO Concentration (mg /L)
82

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 21
FREQUENCY OF COMPLIANCE WITH DAILY AVERAGE DISSOLVED OXYGEN
STATE WATER QUALITY STANDARDS (5.0 MG/L) FOR DAILY AVERAGE
DISSOLVED OXYGEN CONCENTRATIONS AT OXFORD CALCULATED FROM
DISCRETE BUBBLE MODEL IN COMPARISON TO THE HISTORICAL RECORD
12
O
Cz
N
O
iff,
Oxford
Total Number of Days = 1445
I I I I I I I I I
I I I I I I '�" I I I
-
------------- - ------ - ------ -------- ------- ------
---- - - - - "„ ---- - - - - --
mu I
Daly average DO standard
Daily average with aeration
—Daily average without aeration
I I I I I
I I I I I I I I I
I I I I I I I I I
10 20 30 40 50 60 70
Frequency Exceeding DO Concentration ( %)
83
80 90 100

Section 5 Water Quality Assessment and Improvements – Individual Developments
FIGURE 22
COMPARISON OF DAYS OF NON - COMPLIANCE AT OXFORD TO DAILY
AVERAGE DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (5.0
MG/L) CALCULATED FROM DISCRETE BUBBLE MODEL AND THE HISTORICAL
Cn
Q
O
N
%/
L�
M
Oxford
Total Number of Days = 1445
-- - - - - -- L - - - - -- -- - - - - - -- - - - - - --
L- - =-
-- - - - - - - - - - - - - - - L---------- - - - - -- — -- - - - - - - -'- - - - - - - -
-- - - - - -- -------- r-- - - - - -- e" -------- t----- --
---
- - - - - - - -i-------- r -------- r - - - - - - - - i -' - -. - - - - - - - - r - - - - - - r - - - - - - - -
-- - - - - - - - -- - - - - - - -- - - - - - - - - -i -- - - - - - - -
---------------- -' - - -- ------------- - - - - -- - - - - -- -'- -- - - - - - -'- - - - - - - - -
-- - - - - - - - - - - - - - - +------- + - - - - - - - - - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - r - - - r - - - - - - - - - - - - - - - - - - - - - -
- - - - r - - - - - - - -i- - - - - - - - - - - - - - - r - - - - - - - -i - - - - - - - -
�
- - - - - - - - r + - - - - - - - - - - - -ii- - - - - - - - - - - - - - - 7 - - - - - - - - - - - - - -i i- - - - - - - - - - - -
- - - - - - - - - - -
„ - ----------------- - - - -
-
- - - - - - - - - - - - - - - - - - - - - -
-- - - - - - - - - - - - -- -------- L- - - - - - - - -- - - - - -- -----L----------------
r----------------- i- - - - - - - - - - - - - - - - r -------- - - - - - - - - -
------ - - - -�- - --- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - ----- -- -------- -------- - - - - - - --------
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
--------- - - - - - - - - --------
- - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - -�- - - - - - - - -
Dailv average DO standard - -
- - - - - - - - --
- - - a average without aeration
- - - - - - - - -
- - - - - - -
- - - - - - - - -
I)ai1v average Nvith aeration
0 1 2 ; 4 5 6 7 8
DO Concentration (mg/L)
5.3.4.2 Resource Enhancement - Existing Use Standards
According to the NCDENR -NCDWQ Surface Waters and Wetlands Standards (2007) Standards
for Class C Waters and higher classifications, "the haters shall be suitable for aquatic life
propagation and maintenance, of biological integrity, lvildhfe,, secondary recreation, and
agriculture. Sources of water quality pollution which preclude any of these uses on either a
short-term or long -term basis shall be considered to be violating a hater quality standard." This
is the applicable "existing use" water quality standard for hydroelectric operations and addresses
84

Section 5 Water Quality Assessment and Improvements — Individual Developments
the need for any receiving waters to be of suitable quality to provide for appropriate aquatic
communities.
As previously described, the Oxford Development consists of an impoundment (Lake Hickory),
which releases into the regulated river reach downstream. Negotiations with stakeholders
indicated that in addition to meeting water quality standards for DO, the primary management
objectives for the Oxford Development include warmwater fishery and freshwater mussel habitat
enhancement.
The allocation of the water resources of the Oxford Development was based on water quality,
flow /habitat analyses, and negotiation of releases appropriate for addressing the above resource
enhancement goals. These analyses and negotiations lead to the minimum continuous flows for
habitat (150 cfs). Habitat gains as a result of the 150 cfs continuous flow at the Oxford
Development are summarized in Table 18.
85

rl
W
H
0
U
U
rO
I�
A
W
w^ �
I�
4-y
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a
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V
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w
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U
U
U
U
F
s
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I
CC
A
I
�
A
w
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0
0
0
0
0
0
0
0
0
0
0
r7 �
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7 �
O �
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MVO
cz
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4-y
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bA
a
O
bA
V
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w
0
U
U
U
U
F

Section 5 Water Quality Assessment and Improvements — Individual Developments
As a result of negotiations to reach a balanced and sustainable CRA, the negotiated flows for the
Oxford Reach are reduced to a level that delivers less than habitat goals established by NCDENR
and other resource agencies. While continuous minimum flows of 150 cfs provide aquatic
habitat benefits, suitable mitigation is being provided to offset the habitat gains that would have
been realized by implementation of recommended flows. This mitigation is described in the
mitigation package in Section 6 (Flow Mitigation Package) of this SIP.
5.3.5 Evaluation of Potential Reservoir Impacts Resulting from Altering Historic
Flows
Please refer to Section 7.2 (Assessments of Operational Scenarios).
5.4 Lookout Shoals Development
The Lookout Shoals Development consists of the following existing facilities: (1) the Lookout
Shoals Dam consisting of: (a) a 282.08- foot -long concrete gravity bulkhead section; (b) a 933 -
foot -long uncontrolled concrete gravity ogee spillway; (c) a 65- foot -long gravity bulkhead
section; and (d) a 1,287- foot -long, 88- foot -high earth embankment; (2) a 1,155 -acre reservoir
with a normal water surface elevation of 838.1 feet above msl; (3) a powerhouse integral to the
dam, situated between the bulkhead on the left bank and the ogee spillway, containing three main
vertical Francis -type turbines and two smaller vertical Francis -type turbines directly connected to
five generators, the three main generators rated at 8,970 kW, and the two smaller rated at 450
kW for a total installed capacity of 25.7 MW; and (4) other appurtenances (Figure 23).
5.4.1 Current Status
5.4.1.1 North Carolina DWQ Assessments and Water Quality Standards
According to NCDENR (2004), Lookout Shoals Lake was classified as oligotrophic to
mesotrophic with 2 of 7 water quality parameters (percent saturation DO and macrophytes)
identified as lake stressors. NCDWQ identified Lakes Rhodhiss, Hickory, and Lookout Shoals
87

Section 5 Water Quality Assessment and Improvements — Individual Developments
as closely linked watersheds with heavy influence from urban centers and agricultural activities.
Lookout Shoals' immediate drainage is relatively small. Lower Creek, the largest tributary,
drains a predominantly forest and agricultural area and carries a significant sediment load.
The lake's water quality is primarily driven by the upstream releases from the Oxford turbines.
The primary water quality concern in Lookout Shoals is nutrient enrichment, (indicated by high
DO levels) and Parrot Feather (aquatic macrophyte) infestation. [Note: high DO levels may also
result from high macrophyte infestations rather than nutrient driven planktonic algal blooms.]
The upper portion of Lookout Shoals (immediately downstream of Oxford Powerhouse)
exhibited periodic low DO concentrations from Lake Hickory releases.
All waters in the Lookout Shoals basin are fully supporting for recreational and drinking water
use. 14.4 miles of tributaries to the lake were considered impaired to aquatic life.
All waters inside the project boundaries were considered fully supporting the use classification.
Impaired waters outside the project boundaries that potentially influence water quality within the
project include:
■ 303(d) listings for inflows to Lookout Shoals Lake were:
— 14.0 miles of Lower Little River: biological impairment

Section 5 Water Quality„ Assessment and Improvements — Individual Developments
FIGURE 23
LOOKOUT SHOALS DEVELOPMENT
40A ZV44
kO
.` - "``
I
i�W
J.
qj
Lookout Sikoa ls Lf affl .�•"_" 5 :,, 711.
I �
� 1 t
if if�� y � d � • .n; � � �f �d dh i I. �P'
s, r. i f
k� � Ro
: � t� q % ' Lookrut Shoals pw.,oehruse
P
f E
1%
w;f I fi V t� of t !f
Agt
�r�[ s 1
Lookout
k Shoals i .,e
L,R `" � t �r Lake.�Jfjils3n zef ��4 r
s Sfi at} f t
J.e
� F d'-L ff••
Lookout Shoals
i � � � � J "• f � N � S � �� ,f�,"
Tail 6��I
�� �J
S
ff
'h,
�
�y it ti c � ^d �'• ( � � � ,w i� t�"� F r r
l s
"rz
gg
tpb
y 4I r S w P t ar J' t "4� hh} "'d r» +„ 44 i" f i
,O
1�4
jr,�� m � a x u��•� rvj 4 '•� k t Vwn,.t`v "
ILL{
ILI
� �s�� a k '� X k
` l5
Lookout Shoah Development
nh a ''.ins
Catawba- Wateree Project
FER ` NO. 2232
eL t w
89

Section 5 Water Quality Assessment and Improvements — Individual Developments
5.4.1.2 FERC Relicensing Data Summary
Reservoir — Lookout Shoals
Water Quality Findings
The following information was provided in Book 2 of 10, Application for New License
Supplement and Clarification - Study Reports (Duke Energy 2007):
■ With its short retention time, Lookout Shoals Lake is largely inflow driven, so release
temperatures and water quality reflect inflow conditions, particularly from Oxford Hydro.
■ Duke Energy operates the Lookout Shoals hydro for peaking energy or to maintain target
lake levels.
■ Stratification is weak and intermittent. Longer residence times occur at the surface and
near the bottom in the downstream third of the reservoir.
■ Low DO occurs due to sediment oxygen demand in deep forebay areas where residence
time is longer.
■ Algal levels increase at the surface in the downstream third of the reservoir where
residence times are longer.
Biological Resource Findings
The following information on the biological resources of Lookout Shoals Lake was provided in
Book 2 of 10, Application for New License Supplement and Clarification - Aquatics 01 Study
Report (Duke Energy 2007):
■ Twenty -seven species of fish, plus hybrid sunfish, were observed during spring
electrofishing (1994 -1997, 2000).
■ Total fish biomass in these samples averaged 43.1 kg per kilometer of shoreline.
Largemouth bass constituted the largest percentage of biomass, averaging 46 percent;
90

Section 5 Water Quality Assessment and Improvements — Individual Developments
common carp averaged 17 percent, sunfish (primarily bluegill, redear, and redbreast) 16
percent, and white catfish 9 percent.
■ Total density in the littoral fish community averaged 314.2 fish per kilometer of shoreline
and consisted of 41 percent bluegill, 17 percent yellow perch, 15 percent largemouth bass,
and 14 percent redbreast sunfish.
■ Hydroacoustic (1997, 2000) and purse seine sampling (1993 -1997, 2000) indicated that
limnetic densities of forage fish in Lookout Shoals Lake averaged 7,016 fish per hectare.
■ As with the other upper Catawba reservoirs, the composition of the limnetic forage fish
community was extremely variable among years. Gizzard shad accounted for close to 100
percent of the community in 1994, 1995, and 1996, while threadfin shad accounted for
nearly 100 percent in 1993, 1997, and 2000.
■ Variability in forage fish community composition was potentially due to mortality of
threadfin shad at temperatures below 9 °C; winter temperatures on Lookout Shoals Lake
averaged 6.6 °C.
■ No fish kills were reported on Lookout Shoals Lake from 1988 through July 2001.
However, as with reservoirs upstream of Lookout Shoals Lake, winter die -offs of threadfin
shad were likely to have occurred periodically.
Tailrace — Lookout Shoals
Water Quality Findings
The following information was provided in Book 2 of 10, Application for New License
Supplement and Clarification - Study Reports (Duke Energy 2007):
■ Ten years of tailrace continuous monitoring at approximately 5- minute intervals for
temperature, pH, and DO revealed that only DO did not meet state water quality standards
for turbine releases.
■ On the average, during May through November, 8 percent of the hourly average DO
concentrations released from Lookout Shoals hydro exceed the current state standard of 4.0
mg /l instantaneous.
91

Section 5 Water Quality Assessment and Improvements — Individual Developments
• On the average, during May through November, 31 percent of the daily average DO
concentrations released from Lookout Shoals hydro exceed the current state standard of 5.0
mg /1 daily average.
• Actual average nutrient Oxford Releases Compared to Lookout Shoals Releases:
— Phosphorus: Oxford = 22 mg /1; Lookout Shoals = 22 mg /1
— Dissolved Organics: Oxford = 1.9 mg /1; Lookout Shoals = 1.9 mg /1
— Particulate Organics: Oxford = 1.1 mg /1; Lookout Shoals = 1.1 mg /l
5.4.2 Water Quality Issue Identification and Evaluation
Lookout Shoals Tailrace
• Establish higher continuous minimum flow in Catawba River channel.
• Enhance DO concentrations of water released from powerhouse to meet state standards
(minimum flow and generation flows).
5.4.3 Project Modifications for Water Quality Compliance and Resource
Enhancement
Stakeholder negotiations and engineering evaluations have resulted in proposed structural
changes and operational changes, as described below.
92

Section 5 Water Quality Assessment and Improvements — Individual Developments
Proposed Engineering Changes
TABLE 19
SUMMARY OF LOOKOUT SHOALS DEVELOPMENT AERATION CAPABILITIES
Turbine/
Other Release Point
Original
Current
(as of 12/31/2006)
Future
(from FWQIP)
Lookout Shoals Unit 1
OVB
OVB
OVB
Lookout Shoals Unit 2
OVB
OVB
OVB
Lookout Shoals Unit 3
OVB
OVB
OVB
Lookout Shoals Exciter A
OVB
OVB CMR
PRH CMR
Lookout Shoals Exciter B
OVB
OVB CMR
PRH CMR
OVB = Original Vacuum Breaker - Unimproved original vacuum breaker aeration
PRH = Peripheral Ring Header - Peripheral aeration via ring header at top of draft tube
CMR = Dedicated continuous minimum flow turbine, valve or modification
For additional details, refer to the FWQIP shown in Table 4 of the 401 Water Quality
Certification Application.
Proposed Operational Changes
Reservoir —Lookout Shoals
TABLE 20
TARGET RESERVOIR ELEVATIONS FOR LOOKOUT SHOALS LAKE
Elevation (ft) at
start of dap
USGS Datum
I Full Pond = 100
Existing
Proposed
lExisting
Proposed
Januan- 1
836.1
835.1
98
97
Febman- 1
836.1
835.1
98
97
March 1
836.1
835.1
98
97
April
836.1
835.1
98
97
Mai- 1
836.1
835.1
98
97
June 1
836.1
835.1
98
97
July 1
836.1
835.1
98
97
August 1
836.1
835.1
98
97
September 1
836.1
835.1
98
97
October 1
836.1
835.1
98
97
November 1
836.1
835.1
98
97
December 1
836.1
835.1
98
97
93

Section 5 Water Quality Assessment and Improvements — Individual Developments
■ The final habitat flows for the Project in the CRA are based on stakeholder negotiations
and CHEOPS analysis of flow levels that provided improved aquatic habitat and which
were at levels which could be sustained over the life of the license.
■ The Lookout Shoals Development will release 80 cfs continuous minimum flow to the
Catawba River reach by operating an exciter unit continuously when the turbines are not in
operation.
TABLE 21
CONTINUOUS MINIMUM HABITAT FLOWS (CFS) FOR THE
LOOKOUT SHOALS DEVELOPMENT TAILWATER
Month
New License Minimum
Flows (CRA)
Existing Minimum Flows
Januan-
80
80
Febivan-
80
80
March
80
80
April
80
80
May
80
80
June
80
80
July
80
80
August
80
80
September
80
80
October
80
80
November
80
80
December
80
80
5.4.4 Reasonable Assurance of Future Compliance and Resource Enhancement
5.4.4.1 Dissolved Oxygen - Numeric Standards
The use of turbine venting to the Lookout Shoals Project was evaluated by developing a DBM
(Appendix B) for each turbine configuration. Lookout Shoals has three existing turbines with
vacuum breaker venting and two existing exciter units. Post - license, one of the exciter units will
be used to provide the continuous minimum flow of 80 cfs. Both exciter turbines will be aerated
through a peripheral ring header.
94

Section 5 Water Quality Assessment and Improvements — Individual Developments
The calibrated DBM for the turbines was used as a tool to predict the DO uptake of the existing
turbines by solving the calibrated equation with each historical hourly flows, temperatures, and
DO concentrations. These historical mean hourly values were calculated from the long -term
record of water quality measurements made in the Lookout Shoals tailrace at 5- minute intervals.
All predicted DO uptakes resulting from the calibrated DBM equation were compared to the
actual historical monitoring data.
Even with the relatively limited aeration capability of the vacuum breakers, Lookout Shoals
turbine aeration is projected to increase the frequency of compliance with the instantaneous
standard (4.0 mg /1) to 99.7 percent compared to the baseline value of 96.3 percent (Figure 24).
Only 37 hours of the 14,335 hours of past generation flows are not projected to meet the
instantaneous standard (Figure 24). These 37 hours were all recorded in two days in August
2002. Three days later, that particular DO monitor was permanently retired as inoperable. These
two days were the lowest oxygen readings on record at Lookout since monitoring began in 1995
and are suspected of being erroneously low.
The projected frequency of meeting the daily average DO standard of 5.0 mg /1 is 94.9 percent
(compared to 79.5 percent of the baseline) (Figure 25). Of the days that were projected to have a
daily average DO of less than 5.0 mg /1 (89 out of 1924) (Figure 26), most were days when larger
DO deficits were observed and the limited aeration increased the DO to over the 4.0 mg /1 target,
but not to the 5.0 mg /1 needed to comply with the daily average standard.
These aeration applications were made using the initial inflowing DO equal to the measured,
historical oxygen values. However, since Lookout Shoals Lake has an average retention time of
six days (less under higher flows) and is significantly influenced by inflows from Oxford Hydro,
the oxygen concentration in the Oxford flow is a major factor driving the DO observed in
Lookout Shoals Lake. Using the future Oxford aerated flows as inflow to Lookout Shoals in the
CE- QUAL -W2 reservoir model, the significant increase in Lookout Shoals Lake oxygen levels
was validated. In fact, the oxygen originating from Oxford and carried through Lookout Shoals
has greater impact on the tailrace DO than the turbine venting at Lookout Shoals. Using these
95

Section 5 Water Quality Assessment and Improvements – Individual Developments
DO values as input to the DBM instead of the historical DO concentrations resulted in complete
compliance with all DO standards except for two days not meeting the daily average oxygen
concentration (Figure 27). These are the same two days discussed above and are suspect for
underestimating the actual DO.
FIGURE 24
FREQUENCY OF COMPLIANCE WITH INSTANTANEOUS DISSOLVED OXYGEN
STATE WATER QUALITY STANDARDS (4.0 MG/L) FOR HOURLY DISSOLVED
OXYGEN CONCENTRATIONS AT LOOKOUT SHOALS CALCULATED FROM
DISCRETE BUBBLE MODEL IN COMPARISON TO THE HISTORICAL RECORD
12
10
i 8
n
O
6
O
U
2
0
Lookout Shoals
Total Number of Hours = 14335
I ° [—Hourly with aeration
Instantaneous DO standard
Oxford Carry-through with Lookout aeration
Hourly without aeration
Oxford Carry-through without Lookout aeration
0 10 20 30 40 50 60 70 80
Frequency Exceeding DO Concentration ( %)
96
90 100

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 25
COMPARISON OF HOURS ON NON - COMPLIANCE AT LOOKOUT SHOALS TO
INSTANTANEOUS DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS
(4.0 MG/L) FOR HOURLY DISSOLVED OXYGEN CONCENTRATIONS
CALCULATED FROM DISCRETE BUBBLE MODEL AND THE HISTORICAL
RECORD
10,000 —
1,000
100
a�
z
10
I
0
Lookout Shoals
Total Number of Hours = 14335
-- - -- -- - - - - -- - -- - -- - -- --
Instantaneous DO standard - - - - - - - - - - - - - - - - - - - - -
-- -- -- - - -- -- -- - -
----------------- ------ -, w�, - -- - - --
HourIv with aeration ----------------- - --------- - - - - - --
-------
Oxford Carry - through with
------------- - - - - -- - -- - -- ---------
Lookout aeration = ______________' ________'_____--- _'_________
Hourly without aeration - - - - - - - ------ --------- --- - - -
---- --------- - -,- ---------------------
Oxford Canv- through without
-- -------------- --------- ---------
Lookout aeration
-- - - - - -- -------- k--------- _ -____ __ - -___
= = -r = - T= -_ -_ -'_ _'
- - - - - -- - - -- - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
--- - - -- - - - - - - -- - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - -
-- - - - - -- -- - - - - -- -- - - -- - - - - -
-------- *-------- +-- - - - - -- - - - - - - - - - - - - - -
r - - - - - - - - r - - - - - - - r - - - - - - - - - - - - - <. -,- - - - - - - - -,- - - - - - - - - r - - - - - - - -
TT - - - - - - - - - - - - - - - - - - -,- - - - - - - - -i - - - - - - - -
rT - - - - - - - - - - - - -..`,- - - - - - - - -,- - - - - - - - -i - - - - - - - -
r- - - - - - - - - - - - - - - - r - - - - - - - - - „ -,- - - - - - - - -,- - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
i
1 2 3 4 5 6 7 8
DO Concentration (mg/L)
97

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 26
FREQUENCY OF COMPLIANCE WITH DAILY AVERAGE DISSOLVED OXYGEN
STATE WATER QUALITY STANDARDS (5.0 MG/L) FOR DAILY AVERAGE
DISSOLVED OXYGEN CONCENTRATIONS AT LOOKOUT SHOALS CALCULATED
FROM DISCRETE BUBBLE MODEL IN COMPARISON TO THE HISTORICAL
RECORD
12
10
� 8
I~
0
6
a�
U
O
U
2
0
Lookout Shoals
Total Number of Days = 1924
0 10 20 30 40 50 60 70 80 90 100
Frequency Exceeding DO Concentration ( %)
98

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 27
COMPARISON OF DAYS OF NON - COMPLIANCE AT LOOKOUT SHOALS TO
DAILY AVERAGE DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS
(5.0 MG/L) CALCULATED FROM DISCRETE BUBBLE MODEL AND THE
HISTORICAL RECORD
Q
0
a�
21
1,000
100
10
1
Lookout Shoals
Total Number of Days = 1924
0 1 2 3 4 5 6 7 8
DO Concentration (mg/L)
5.4.4.2 Resource Enhancement - Existing Use Standards
According to the NCDENR -NCDWQ Surface Waters and Wetlands Standards (2007) Standards
for Class C Waters and higher classifications, "the waters shall be suitable for aquatic life
propagation and maintenance of biological integrity, wildh/e, secondary recreation, and
agriculture. Sources of water quality pollution which preclude any of these uses on either a
short-term or long -term basis shall be considered to be violating a water quality standard." This
99

Section 5 Water Quality Assessment and Improvements — Individual Developments
is the applicable "existing use" water quality standard for hydroelectric operations and addresses
the need for any receiving waters to be of suitable quality to provide for appropriate aquatic
communities
As previously described the Lookout Shoals Development consists of an impoundment (Lookout
Shoals Lake) which releases into Lake Norman downstream. Under extreme drawdowns this
reach takes on characteristics similar to a regulated river reach. However, since this only occurs
during the winter drawdown period for Lake Norman negotiations with stakeholders indicated
that in addition to meeting water quality standards for DO the primary management objective for
the Lookout Shoals Development included reservoir fishery habitat enhancement.
The allocation of the water resources of the Lookout Shoals Development was based on water
quality, flow /habitat analyses, and negotiation of releases appropriate for addressing the above
resource enhancement goals. Wetted perimeter analyses indicated that achieving flow /habitat
goals would require flows which could not be sustained by the Project over the term of a New
License.
Based on CHEOPS analysis and mutual gains negotiations, flows for the Lookout Shoals
Development are 80 cfs year - round. This level of flow is sustainable for the term of a New
License. To compensate for not fully meeting state resource agency goals for river habitat, the
CRA also provides mitigation for the Lookout Shoals Regulated Reach (see Section 6 [Flow
Mitigation Package] of this SIP).
5.4.5 Evaluation of Potential Reservoir Impacts Resulting from Altering Historic
Flows
Please refer to Section 7.2 (Assessments of Operational Scenarios).
100

Section 5 Water Quality Assessment and Improvements — Individual Developments
5.5 Cowans Ford Development
The Cowans Ford Development consists of the following existing facilities: (1) the Cowans
Ford Dam consisting of: (a) a 3,535- foot -long embankment; (b) a 209.5- foot -long gravity
bulkhead; (c) a 465- foot -long concrete ogee spillway with 11 Tainter gates, each 35- feet -wide by
28- feet -high; (d) a 276 - foot -long bulkhead; and (e) a 3,924- foot -long earth embankment; (2) a
3,134- foot -long saddle dam (Hicks Crossroads); (3) a 32,339 -acre reservoir with a normal water
surface elevation of 760 feet above msl; (4) a powerhouse integral to the dam, situated between
the spillway and the bulkhead near the right embankment, containing four vertical Kaplan -type
turbines directly connected to four generators rated at 83,125 kW for a total installed capacity of
332.5 MW; and (5) other appurtenances (Figure 28).
5.5.1 Current Status
5.5.1.1 North Carolina DWQ Assessments and Water Quality Standards
Lake Norman is the largest of the Catawba River reservoirs according to the NCDENR (2004)
Lake Norman has consistently been evaluated as oligotrophic with low nutrient concentrations
and low algal production. The lake is used as a public water supply and for recreation.
NCDENR (2004) reported elevated DO levels, elevated nutrient and metal levels, as well as
boating congestion. Lake Norman's large volume has allowed the lake to absorb these human
induced impacts and maintain reasonable water quality.
All waters inside and outside the project boundaries were considered fully supporting the use
classification.
101

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 28
COWANS FORD DEVELOPMENT
Cowans Ford
Pmoverhouse
' Lake �i7 fPf?�f6
f K '
k �
v
r(� 3
ow is Ford
r Cou ans
lrac
P-1 11
-t
e "Y 04, , r
VIM
i
�-. '4% ;1f i�I v
Mountain Is
Ian Lakes
ys��;14,u-
r der j� �t �4
1S
.
r i k p/
�
I I i & 4 i 4 10
¢sa {4t
,' XJ f '�'t�„
FldO
I aJ
t r
aQ "dr
4
4 !
4
4 " ( r,� �� 4`� I I f * �s�,ti�lf
1 uhf r hk. 4
VI� + e ;
t
Y+ r }
4 r
fi, s A t l a I `"+, - ¢ d
3 y s €� S P Hwy
I a #-
" +�I rI f
4t ,
zp
wI CCU,
OT N, 4 4
"t
Cowans Ford Development
Catawba- Wateree Project
FFC'C). X237
102

Section 5 Water Quality Assessment and Improvements — Individual Developments
5.5.1.2 FERC Relicensing Data Summary
Reservoir — Cowans Ford (Lake Norman)
Water Quality Findings
The following information was provided in Book 2 of 10, Application for New License
Supplement and Clarification - Study Reports (Duke Energy 2007):
■ Lake Norman is the largest storage reservoir on the Catawba System.
■ With its long retention time (239 days on average), Lake Norman has good water quality.
■ Duke Energy operates the Cowans Ford Development for peaking energy or downstream
water demands within the guidelines of a seasonal lake level target.
■ Overall according to NCDWQ, water quality is good.
■ Lake Norman stores the cold, well oxygenated winter inflows. Duke Energy manages this
coldwater resource for cooling water for Marshall Steam Station and McGuire Nuclear
Station.
■ A submerged skimmer weir immediately upstream of Cowans Ford Development prevents
the turbines from accessing the deep, coldwater stored in the lake and allows the warm,
oxygenated surface water to be released downstream.
■ Thermal stratification is both a function of the bathymetric restriction imposed by the
skimmer weir and the use of the coldwater by Marshall and McGuire steam stations.
■ The primary source of nutrients and organic matter is from the Lookout Shoals releases.
■ Algae are significant near the mid to upper lake where nutrients are highest; as nutrients
are depleted, algal activity decreases progressively towards Cowans Ford Dam.
■ The organic material, received from both Lookout Shoals and from the algae produced in
the lake, contribute to the lower DO concentrations in the deeper layers.
■ Lake Norman acts as a major trap for phosphorus, due to sorption onto inorganic sediments
that settle out of the water column.
103

Section 5 Water Quality Assessment and Improvements — Individual Developments
Biological Resource Findings
The following information on the biological resources of Lake Norman was provided in Book 2
of 10, Application for New License Supplement and Clarification - Aquatics 01 Study Report
(Duke Energy 2007):
• Thirty -five species of fish, plus hybrid sunfish, were observed during spring electrofishing
(1993 -1997, 1999 - 2002). This sampling was conducted in an uplake area in the vicinity of
Marshall Steam Station; a mid- reservoir area in the main channel just upstream of the
confluence with the Davidson Creek arm; and in the forebay area in the vicinity of
McGuire Nuclear Station.
• Taxonomic composition of the littoral fish community was similar among reservoir
regions. Largemouth bass comprised 33 percent to 39 percent of total fish biomass,
common carp 25 percent to 35 percent, and sunfish (primarily bluegill, redbreast, and
redear) 14 percent to 23 percent. In terms of fish numbers, the community was dominated
by sunfish (54 percent to 60 percent of total fish density), shiners (17 percent to 20
percent), and largemouth bass (9 percent to 14 percent).
• Total fish biomass averaged 37.5 kilograms per kilometer of shoreline in the uplake area,
31.7 kg /km in the mid- reservoir area, and 20.3 kg /km in the vicinity of the forebay.
• Hydroacoustic (1997, 2000) and purse seine sampling (1993 -1997, 2000) indicated that
lmnetic densities of forage fish in Lake Norman averaged 24,172 fish per hectare.
• Limnetic forage fish abundance in Lake Norman was estimated via hydroacoustic
sampling (1997- 2003). Sampling was conducted in six zones from headwaters to forebay.
Mean densities of forage fish ranged from 2,189 fish/ha in Zone 6, a more riverine area in
the headwaters of Lake Norman, to 9,636 fish/ha in Zone 5.
• Limnetic forage fish community taxonomic composition was determined using purse seine
sampling (1993- 2003). From 1993 through 1998, the forage fish community was almost
entirely of threadfin shad; in contrast to reservoirs upstream, mean winter temperatures in
some areas of Lake Norman exceed the level at which threadfin shad become thermally
stressed.
104

Section 5 Water Quality Assessment and Improvements — Individual Developments
■ In 1999, alewife appeared in Lake Norman purse seine samples for the first time,
potentially as a result of angler `bait - bucket' introduction. From 2000 through 2003,
alewife comprised 17 percent of fish in purse seine samples, on average.
■ During the period from 1988 through July 2001, two fish kills were reported in the Lake
Norman watershed. In August 1990, mortality of an estimated 150 striped bass was
reported on Lake Norman.
■ In April 1997 a kill of 170 catfish was reported for Lyle Creek, a tributary of Lake
Norman, due to a toxic spill from the Conover Northeast waste water treatment plant.
■ In mid- summer 2004, mortality of approximately 2,500 striped bass was reported on Lake
Norman. The die -off was attributed to trapping of striped bass in the hypolimnion due to
low metalimnetic oxygen levels, followed by mortality as oxygen concentrations in the
hypolimnion declined to near zero.
Tailrace — Cowans Ford
Water Quality Findings
The following information was provided in Book 2 of 10, Application for New License
Supplement and Clarification - Study Reports (Duke Energy 2007):
■ Ten years of tailrace continuous monitoring at approximately 5- minute intervals for
temperature, pH, and DO revealed that only DO did not meet state water quality standards
for turbine releases.
■ On the average, during May through November, 1 percent of the hourly average DO
concentrations released from Cowans Ford Development are lower than the current state
standard of 4.0 mg /1 instantaneous.
■ On the average, during May through November, 7 percent of the daily average DO
concentrations released from Cowans Ford Development are lower than the current state
standard of 5.0 mg /1 daily average.
■ Actual 4 -year (1997 -2000) average nutrient Lookout Shoals releases compared to Cowans
Ford Releases:
105

Section 5 Water Quality Assessment and Improvements — Individual Developments
— Phosphorus: Lookout Shoals = 22 mg /1; Cowans Ford = 11 mg /l
— Dissolved Organics: Lookout Shoals = 1.9 mg /1; Cowans Ford = 1.7 mg /1
— Particulate Organics: Lookout Shoals = 1.1 mg /1; Cowans Ford = 0.6 mg /1
5.5.2 Water Quality Issue Identification and Evaluation
Reservoir — Cowans Ford (Lake Norman)
■ Minimize water quality impacts within reservoir resulting from altering historic.
Cowans Ford Tailrace
■ Enhance DO concentrations of water released from powerhouse to meet state standards.
5.5.3 Project Modifications for Water Quality Compliance and Resource
Enhancement
Stakeholder negotiations and engineering evaluations have resulted in no proposed hydro
equipment modifications. Lake levels are proposed to be generally equal to or higher than
current practice.
Existing Hydro Turbines
TABLE 22
COWANS FORD DEVELOPMENT AERATION CAPABILITIES
Turbine/
Other Release Point
Original
Current
(as of 12/31/2006)
Future
(from FWQIP)
Cowans Ford Unit 1
NKR
NKR
NKR
Cowans Ford Unit 2
NKR
NKR
NKR
Cowans Ford Unit 3
NKR
NKR
NKR
Cowans Ford Unit 4
NKR
NKR
NKR
NKR = None - Kaplan Runner - Conventional aeration is not possible on a Kaplan numer.
106

Section 5 Water Quality Assessment and Improvements - Individual Developments
Proposed Operational Changes
TABLE 23
TARGET RESERVOIR ELEVATIONS FOR LAKE NORMAN
Elevation (ft)at
start of day
USGS Datum
I Full Pond = 100
Existing
Proposed
lExisting
Proposed
Januan- 1
754.7
756.0
94.7
96.0
Febman- 1
753.3
754.0
93.3
94.0
March 1*
752.0
755.3
92.0
95.3
April 1*
754.0
756.7
94.0
96.7
May 1
756.0
758.0
96.0
98.0
June 1
758.0
758.0
98.0
98.0
J111v 1
758.0
758.0
98.0
98.0
August 1
758.0
758.0
98.0
98.0
September 1 **
758.0
758.0
98.0
98.0
October 1
757.3
758.0
97.3
98.0
November 1
756.7
757.0
96.7
97.0
December 1
756.0
1756.0
196.0
196.0
*Elevations to the nearest tenth of a foot.
* *This date is September 5 for existing normal target elevation.
■ One unit at the Cowans Ford Development is run at efficiency load at least once each day,
generating approximately 44 MWh to meet the MADF license requirement of 311 cfs.
■ In addition, the reservoir stabilization program for enhancement of largemouth bass
spawning will be continued for Lake Norman.
5.5.4 Reasonable Assurance of Future Compliance and Resource Enhancement
5.5.4.1 Dissolved Oxygen - Numeric Standards
Only an historical DO frequency curve is provided for the Cowans Ford Development generation
because no turbine aeration is proposed for the turbines. The station is unique for the Catawba
hydros since it has four Kaplan units compared to the usual Francis turbines. Kaplan units
cannot be vented (no vacuum drawn) and are not readily aerated. Cowans Ford is also unique for
the Catawba hydros since it has a skimmer weir in the reservoir in front of the turbine intakes
(crest of the weir is at 725 msl elevation which is 35 feet deep at full pond). This skimmer weir
107

Section 5 Water Quality Assessment and Improvements — Individual Developments
(reference Figure 29 below) causes the turbines to receive relatively high DO surface water from
the reservoir.
FIGURE 29
ILLUSTRATION OF SKIMMER WEIR AT COWANS FORD DEVELOPMENT
108

Section 5 Water Quality Assessment and Improvements — Individual Developments
The daily average DO exceedance curve from the historical record (Figure 30) crosses the 4.0
mg /1 instantaneous standard at 99.2 percent with 45 hours (out of 5902 hours, Figure 31)
exhibiting less than the 4.0 mg /1 standard. The frequency of the Cowans Ford tailrace exhibiting
DO values equal to or greater than the daily average DO standard of 5.0 mg /1 was 91.4 percent
(Figure 32), or 159 of 1851 days (Figure 33).
These infrequent low DO values are typically the result of fouled DO sensors. Duke
(unpublished data) investigated low tailrace DO readings twice in 1998. On both occasions the
sensor was reading too low. This was established by a check with a calibrated instrument, but
more significantly, the tailrace temperature and DO always tracked within the maximum and
minimum temperature and maximum and minimum DO ranges that were observed above the
skimmer weir in Lake Norman (Figure 34). When the sensor was fouled, the temperatures track
as normal, but the DO in the tailrace falls below the minimum value recorded in the lake. This
evidence shows that the Cowans Ford tailrace receives water predominantly from above the
skimmer weir.
Not every incident of low DO was investigated at Cowans Ford; however, assuming that on the
average, a fouled sensor was reading 0.5 mg /1 too low, the number of hours not meeting the 4.0
mg /1 standard decreases to 16 hours and the frequency of compliance increases to 99.7 percent.
Using the same approach for the daily average reduces the number of days not meeting the 5.0
mg /1 standard from 159 days to 56 days and the frequency of compliance with the 5.0 mg /1
standard increases from 91.4 percent to 97 percent.
When the preceding considerations are combined with other conservatisms (Section 4.2.6) and
the monitor location is improved (refer to Appendix A), there is reasonable assurance that
Cowans Ford Hydro can meet state standards for DO.
109

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 30
FREQUENCY OF COMPLIANCE WITH INSTANTANEOUS DISSOLVED OXYGEN
STATE WATER QUALITY STANDARDS (4.0 MG/L) FOR HOURLY DISSOLVED
OXYGEN CONCENTRATIONS AT COWANS FORD CALCULATED FROM
DISCRETE BUBBLE MODEL IN COMPARISON TO THE HISTORICAL RECORD
12
on
I~
0
U
O
U
Cowans Ford
Total Number of Hours = 5902
r 7 = - - - - - - - - - - - - -- - - - - - - - - - - T
i
IiourIv without aeration
- -- - - -- - - - -- - - - -- - - - -- - - - - -- - - - --
Instantaneous DO standard
10 20 30 40 50 60 70 80
Frequency Exceeding DO Concentration ( %)
110
90 100

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 31
COMPARISON OF HOURS OF NON - COMPLIANCE AT COWANS FORD TO
INSTANTANEOUS DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS
(4.0 MG/L) FOR HOURLY DISSOLVED OXYGEN CONCENTRATIONS
CALCULATED FROM DISCRETE BUBBLE MODEL AND THE HISTORICAL
RECORD
i-4
O
U
x 1��
O
U
2
IM
Cowans Ford
Total Number of Hours = 5902
-- - - - - - - - -----------------------------------------------------
-- - - - - - - - - - - - - - - -
-- - - - - - - - - - - - - - - - -- - -
-- - - - - - - -- - - - - -- --------
I I
-- - - - - - - - - - - - - -- -- - -
I I
- - - - - - - - - - - - - - - - - -------- - -
- - - - - - - -------- --------
- - - - - - - -I-------- + --------
-- - - - - - - - - - - - - - - - - - - -
- - - - - - - - - -
- - - - - -- - - - ---
+ - - - --
I
- - -- - - - - - - - -
I
______________
- - - - - - - -
- - - - - - - - - -
- - - - -
r --------
- - - - - - - - - - -
- - - - - -
-------------------
--------+--------r-----------
I
- --
I
___
- - - - - - - - Y -
- - - - - - - - - -
- - - - - - - --------
- - - - - + --------
- - - - - +-
- - - - - -
----
- - - - - - - - - - - -- - - - - --
- - - - - - -
- ------
I
- - - - -- - -- -- - - - - ---
I
__ __ _________'-______-
- - - - - r - - - - - - - -I- - - - - - - -
- - - - - - - - - - - - - - - - --------
--------
r -------- - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - -
I I
I I
---------------- 1--------
- - - - - - - - - - - - - - - - T - - - -
- - - - - - - -'- - - - - - - - 1 - - - -
- - - - - - - - - - - - - - - - -
- - - - - - - - I -- - - - - - - - -- - -
--------i--------+--------r--
I I
I I
-- - - - - - --- - - - - -- - - - -
--------- -- - - - - --T
----------- 1 - - - -
- - - - - - - -'-
- - - - - - - -I- - - - - - - - 1 --------
-------- -- - - - - - - -' --------
I
I
L- - - - - -- --
- - - - r - - - - - - - -
- - - - -
L - - - - - - -
- - - - - - - - -
- - - -r- - - - -
- - - -
I
I
- - -- - - - --
-
r- ----- _-----
- - - - L - - - - - -
'- - - - - -
I
I
- - _- - - ---- -
-
- - - - - - - T -
- -
- - - - - - 1 -
- - - - - -
- - - - - - - -,-
- - - - - - - -+-
I
I
- - - - - - -- --
- - - - -7
- - - - - - - 1 -
��-- - - - - --
I I
I I
- - - - - - - --------- - - - - -- -
- - - - - - - r - - - - - - - -I- - - - - - - -
- - - - - - - L - - - - - - - -'- - - - - - -
- - - - - - - - - - - - - - - - - - -
- -------
- - - - - - -r- - - - - - - -
- - - - - - -r- - - - - - - - - - - - - - - -
I I
I I
- - - - -- --------- - - - - -- -
r _
- - - - - - - L -------- I -- - - - - -
Hourly without aeration
--
-- - - - - - - - - - - - - - - rt- - - -
I I
I
- - - -� - - - - --
I
- - - - --
I
Instantaneous DO standard
I I
--
DO Concentration (mg /1)
111

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 32
FREQUENCY OF COMPLIANCE WITH DAILY AVERAGE DISSOLVED OXYGEN
STATE WATER QUALITY STANDARDS (5.0 MG/L) FOR DAILY AVERAGE
DISSOLVED OXYGEN CONCENTRATIONS AT COWANS FORD CALCULATED
FROM DISCRETE BUBBLE MODEL IN COMPARISON TO THE HISTORICAL
RECORD
12
f[11
� 8
I~
6
U
O
R
0
Cowans Ford
Total Number of Days = 1851
r 7 - - - - -- - - - - T
- - - - --
Daly' average without aeration
Daily average DO standard
10 20 30 40 50 60 70 80
Frequency Exceeding DO Concentration ( %)
112
90 100

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 33
COMPARISON OF DAYS OF NON - COMPLIANCE AT COWANS FORD TO DAILY
AVERAGE DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS (5.0
MG/L) CALCULATED FROM DISCRETE BUBBLE MODEL AND THE HISTORICAL
0
U
O
3-i
i-4
w
2
Cowans Ford
Total Number of Days = 1851
--------,----------------- -------- --- - - - - -- - - - - -- -- - - - - --
-- - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - -- - - - -
- - - -- ---- - - - - --
-------- 1--------- 1-------- 1-------- L------ -- -
--------- - -' - -- --- L-- - - - - --
-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - -- - - - - - - - - L- - - - - - - - - - - - -- - - - - -- - - - - - --
- - - - - -- -------- L- - - - - -- ------ - - - - -- - - - - - --
I I I I I I
I I I I I I
I I I I I I
----------------------------------- - - - - -- - -------------------------
-- - - - - - - - - - - - - - - - - - - - - - - -
i - - - - - - L - - - - - - - - - - - - i-- - - - - -_
- - - - - - -'- - - - - - - - -'- - - - - - - - 1 - - - - - - - - L - - - - - - - - - - - -'- - - - - - - - 1 - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - -- -
- - - - - - -,- - - - - - - - - -------- { -------- { -- -------------- -- - - - - - -
I I I I I
I I I I I
I I I I I
I I I I I I
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - { - - - - - - - - - - - - - - -,- - - - - - - - { - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - -I- - - - - - - - -I- - - - - - - - - - - - - - - - - - -
Daily average without aeration - - -
{- - - - - - - - -- - --
Dai v average DO standard
I I I I I I
2 ; 4 5 6 7 8
DO Concentration (mg /1)
113

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 34
COMPARISON OF THE RANGE OF DISSOLVED OXYGEN ABOVE THE SKIMMER
WEIR IN THE FOREBAY OF COWANS FORD AND COWANS FORD TAILRACE
DISSOLVED OXYGEN - EVIDENCE OF SENSOR FOULING
owens Ford
8
7
0)6
E
(D
(D 5
0)
4
(D 3
0
LO
co 2
1
0
21 -Jul 26 -Jul 31 -Jul 05 -Aug 10 -Aug
1998
— DO Tailrace Max DO above Skimmer Weir
x Mean DO above Skimmer Weir - Min DO above Skimmer Weir
5.5.4.2 Resource Enhancement - Existing Use Standards
According to the NCDENR -NCDWQ Surface Waters and Wetlands Standards (2007) Standards
for Class C Waters and higher classifications, "the haters shall be suitable for aquatic life
propagation and maintenance Of biological integrity, irildhfe, secondary recreation, and
agriculture. Sources of water quality pollution which preclude any of these uses on either a
short-term or long -term basis shall be considered to be violating a hater quality standard." This
is the applicable "existing use" water quality standard for hydroelectric operations and addresses
the need for any receiving waters to be of suitable quality to provide for appropriate aquatic
communities.
114

Section 5 Water Quality Assessment and Improvements — Individual Developments
At "lake -to- lake" tailraces (Rhodhiss, Lookout Shoals, Cowans Ford, Mountain Island, Fishing
Creek, Great Falls /Dearborn, and Rocky Creek/Cedar Creek), the downstream reservoir backs up
into the powerhouse tailrace. At these lake -to -lake locations, the tailwater character will remain
lacustrine in nature and would not reasonably be expected to change in nature under minimum
continuous flows that are more appropriately intended to enhance riverine aquatic habitat.
However, the reservoir headwater in the vicinity of the hydro tailrace may benefit from DO
enhancements.
Based on known aquatic resources and the anticipated improvements in DO levels in the Cowans
Ford tailrace, which are anticipated as a result of a New License consistent with applicable
sections of the CRA, the Cowans Ford Development will comply with the NCDWQ existing use
water quality standard.
5.5.5 Evaluation of Potential Reservoir Impacts Resulting from Altering Historic
Flows
Please refer to Section 7.2 (Assessments of Operational Scenarios).
5.6 Mountain Island Development
The Mountain Island Development consists of the following existing facilities: (1) the Mountain
Island Dam consisting of: (a) a 997 - foot -long, 97- foot -high uncontrolled concrete gravity ogee
spillway; (b) a 259- foot -long bulkhead on the left side of the powerhouse; (c) a 200 - foot -long
bulkhead on the right side of the powerhouse; (d) a 75- foot -long concrete core wall; and (e) a
670 - foot -long, 140 - foot -high earth embankment; (2) a 3,117 -acre reservoir with a normal water
surface elevation of 647.5 feet above msl; (3) a powerhouse integral to the dam, situated between
the two bulkheads, containing four vertical Francis -type turbines directly connected to four
generators rated at 15,000 kW for a total installed capacity of 55.1 MW; and (4) other
appurtenances (Figure 35).
115

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 35
MOUNTAIN ISLAND DEVELOPMENT
116

Section 5 Water Quality Assessment and Improvements — Individual Developments
5.6.1 Current Status
5.6.1.1 North Carolina DWQ Assessments and Water Quality Standards
Mountain Island Lake is located immediately downstream of Lake Norman and is used as a
public water supply and for recreation. The lake is considered oligotrophic with low nutrient
concentrations and good water clarity. The recent drought conditions may have decreased non -
points source runoff throughout the basin.
Extensive management efforts are underway in the McDowell Creek Cove and drainage area
since most of McDowell Creek watershed is considered impaired. NCDWQ encourages
protection measures for all of the watersheds in this highly urbanized area.
All waters inside the project boundaries were considered fully supporting the use classification.
Impaired waters outside the project boundaries that potentially influence water quality within the
project include:
■ 303(d) listings for inflows to Mountain Island Lake were:
— 7.3 miles of McDowell Creek: biological impairment
117

Section 5 Water Quality Assessment and Improvements — Individual Developments
5.6.1.2 FERC Relicensing Data Summary
Reservoir - Mountain Island Lake
Water Quality Findings
The following information was provided in Book 2 of 10, Application for New License
Supplement and Clarification - Study Reports (Duke Energy 2007):
■ With its short retention time (12 days on average), Mountain Island Reservoir is largely
driven by the inflows of Cowans Ford, so release temperatures and water quality reflect
these inflow conditions.
■ Overall according to NCDWQ, water quality is good.
■ Duke Energy operates the Mountain Island hydro for peaking energy or to maintain target
lake levels.
■ Thermal loading from Riverbend Steam Station, coupled with high, periodic flows from
Cowans Ford cause weak and intermittent stratification.
Biological Resource Findings
The following information on the biological resources of Mountain Island Lake was provided in
Book 2 of 10, Application for New License Supplement and Clarification - Aquatics 01 Study
Report (Duke Energy 2007):
■ Twenty -eight species of fish, plus hybrid sunfish, were observed in spring electrofishing
(1993 -1997, 1999 -2002) on Mountain Island Lake. Mean total fish biomass averaged
45.8 kilograms per kilometer of shoreline.
■ Common carp comprised 40 percent of total fish biomass, largemouth bass 33 percent, and
sunfish (primarily redbreast, bluegill, and redear) 17 percent.
■ By number, sunfish accounted for 69 percent of total fish density, and largemouth bass for
21 percent.
118

Section 5 Water Quality Assessment and Improvements — Individual Developments
■ Limnetic forage fish densities were determined for Mountain Island Lake with
hydroacoustic sampling (1997, 1999 - 2003). Annual estimates ranged from 998 to 4,554
fish/ha, averaging 3,102 fish/ha.
■ Limnetic fish species composition was also determined using purse seine sampling (1993-
2003, with the exception of 1998).
■ Threadfin shad accounted for an average of 96 percent of forage fish in purse seine
samples from 1993 through 1999, with the remainder consisting of gizzard shad.
■ Alewife first appeared in purse seine samples in 1999, presumably as a result of
downstream movement from Lake Norman, where this species was suspected to have been
introduced by anglers.
■ Alewife comprised 12 percent of the forage fish density on Mountain Island Lake from
2000 -2002. In 2003, however, the relative abundance of this species increased
dramatically; alewife accounted for 83 percent of fish in purse seine samples.
■ No fish kills have been reported on Mountain Island Lake. Mean winter water
temperatures exceeded 9 °C, permitting year -round survival of threadfin shad.
Mountain Island Tailrace
Water Quality Findings
The following information was provided in Book 2 of 10, Application for New License
Supplement and Clarification - Study Reports (Duke Energy 2007):
■ Ten years of tailrace continuous monitoring at approximately 5- minute intervals for
temperature, pH, and DO revealed that only DO did not meet state water quality standards
for turbine releases.
■ On the average, during May through November, 1 percent of the hourly average DO
concentrations released from Mountain Island hydro are lower than the current state
standard of 4.0 mg /1 instantaneous.
119

Section 5 Water Quality Assessment and Improvements — Individual Developments
■ On the average, during May through November, 4 percent of the daily average DO
concentrations released from Mountain Island hydro are lower than the current state
standard of 5.0 mg /1 daily average.
■ Actual 4 -year (1997 -2000) average nutrient Cowans Ford releases compared to Mountain
Island Releases:
— Phosphorus: Cowans Ford = 11 mg /1; Mountain Island = 11 mg /1
— Dissolved Organics: Cowans Ford = 1.7 mg /1; Mountain Island = 1.7 mg /1
— Particulate Organics: Cowans Ford = 0.6 mg /1; Mountain Island = 1.1 mg /1
Mountain Island Bypassed Reach
Biological Resource Findings
The following information on the biological resources of Mountain Island Lake Bypassed Reach
was provided in Book 2 of 10, Application for New License Supplement and Clarification -
Aquatics 01, and Aquatics 06 Study Reports (Duke Energy 2007):
■ The Mountain Island Bypassed Reach contains primarily seepage flows from the base of
the Mountain Island Dam. This bypassed reach of stream is characterized by wetlands
areas, isolated pools, with rock outcrops.
■ The Mountain Island Bypassed Reach sampling area included a small stream on the east
side of the bypass channel (approximately RM 171.4). This stream segment was
qualitatively sampled by backpack electrofishing techniques to determine fish species
composition.
■ The species composition of the fish community at the Mountain Island Bypassed Reach
was typical for the habitat type present in this reach with 5 fish species and 73 individuals
being collected.
■ Eastern mosquitofish and largemouth bass comprised 79 percent of the total number of
individuals collected. The fish species collected in this reach are rated as intermediate to
tolerant of pollution by the NCDWQ.
120

Section 5 Water Quality Assessment and Improvements — Individual Developments
■ In addition to the fish community discussed above, the Mountain Island Bypassed Reach
also provides habitat for populations of the freshwater mussel species: Elliptio complanata,
Elliptio icterina, Elliptio angnstata, Elliptio prodncta, Vnio merits Sp., Vtterbackia
imbecillis, _1vganodon cataracts, ,Strophitns nndnlatns, and Villosa delnmbis. An
extensive and robust mussel community was observed at this location. Other mussel
species observed in this area include Asiatic clams (('Orbicnla flnminea).
■ The federally - listed endangered species, the Schweinitz's sunflower (Helianthns
sclnveinitzii), has become established in the bypass channel. The current habitat in this
location supports a large and stable colony of this species.
5.6.2 Water Quality Issue Identification and Evaluation
Even though the North Carolina DWQ assessment of the Mountain Island Development waters is
deemed compatible with the ascribed designated use, the tailrace and bypassed reach of the
Mountain Island Development was not meeting state water quality standards. Therefore, the
primary issue dealing with water quality is to protect the water quality where standards were met,
and to bring appropriate areas up to state water quality standards.
Mountain Island Tailrace
■ Enhance DO concentrations of water released from powerhouse to meet state standards
(minimum flow and generation flows).
Mountain Island Bypassed Reach
■ Manage Schweinitz's sunflower populations.
■ Mitigate for unavoidable aquatic habitat loss in dewatered bypass reach.
121

Section 5 Water Quality Assessment and Improvements — Individual Developments
5.6.3 Project Modifications for Water Quality Compliance and Resource
Enhancement
Stakeholder negotiations and engineering evaluations have resulted in proposed structural
changes and operational changes.
Proposed Engineering Changes
TABLE 24
SUMMARY OF MOUNTAIN ISLAND DEVELOPMENT AERATION CAPABILITIES
OVB = Original Vacuum Breaker - Unimproved original vacuum breaker aeration
HSV = Hollow Stay Vane - Aeration through existing hollow stay vanes
For additional details, refer to the FWQIP shown in Table 4 of the 401 Water Quality
Certification Application.
122
Mountain Island Development: Aeration Capabilities
Turbine /
Other Release Point
Original
Current
(as of 12/31/2006)
Future
(from FWQIP)
Mountain Island Unit 1
OVB
HSV
HSV
Mountain Island Unit 2
OVB
HSV
HSV
Mountain Island Unit 3
OVB
HSV
HSV
Mountain Island Unit 4
OVB
HSV
HSV
OVB = Original Vacuum Breaker - Unimproved original vacuum breaker aeration
HSV = Hollow Stay Vane - Aeration through existing hollow stay vanes
For additional details, refer to the FWQIP shown in Table 4 of the 401 Water Quality
Certification Application.
122

Section 5 Water Quality Assessment and Improvements — Individual Developments
Proposed Operational Changes
Reservoir — Mountain Island Lake
TABLE 25
TARGET RESERVOIR ELEVATIONS FOR MOUNTAIN ISLAND LAKE
Elevation (ft) at
start of dap
USGS Datum
Full Pond = 100
Existing
Proposed
Existing
Proposed
Januan- 1
644.5
643.5
97
96
Febnian- 1
644.5
643.5
97
96
March 1
644.5
643.5
97
96
April
644.5
643.5
97
96
Mai- 1
644.5
643.5
97
96
June 1
644.5
643.5
97
96
July 1
644.5
643.5
97
96
August 1
644.5
643.5
97
96
September 1
644.5
643.5
97
96
October 1
644.5
643.5
97
96
November 1
644.5
643.5
97
96
December 1
644.5
643.5
97
96
■ One unit at the Mountain Island Development is run at efficiency load at least once each
day, generating approximately 33 MWh to meet the MADF license requirement of 314 cfs.
Mountain Island Bypassed Reach
■ This location is unique in that a large colony of a federally - listed endangered species, the
Schweinitz's sunflower, has become established in the bypass channel. The current habitat
in this location supports this species. Due to the short length of this bypass and in order to
not alter the habitat supporting this rare sunflower species, stakeholders agreed to not
introduce higher flow releases and to fully mitigate for the aquatic habitat not realized in
the Mountain Island Bypass.
123

Section 5 Water Quality Assessment and Improvements — Individual Developments
5.6.4 Reasonable Assurance of Future Compliance and Resource Enhancement
5.6.4.1 Dissolved Oxygen - Numeric Standards
The applicability of turbine venting at the Mountain Island project was evaluated by developing
a DBM (Appendix B) for each turbine configuration (Mountain Island = 4 HSV units). The
DBM for each unit was developed by using the field data from the Rhodhiss HSV units (very
similar to those at Mountain Island) and from the draft tube configuration at Mountain Island.
The DBM for the turbines was used as a tool to predict the DO uptake of the existing turbines by
solving the calibrated equation with each historical hourly flows, temperatures, and DO
concentrations. These historical mean hourly values were calculated from the long period of
record of water quality measurements made in the Mountain Island tailrace at 5- minute intervals.
All predicted DO uptakes resulting from the calibrated DBM equation were compared to the
actual historical monitoring data and state DO standards (Figures 36 through 39).
Mountain Island has very good water quality, with consistently relatively high DO
concentrations observed in the tailrace. Mountain Island has a short retention time and receives
99 percent of its water from Cowans Ford (epilimnion of Lake Norman) which is high in DO.
This water can easily be aerated by the hollow stay vane units at the hydro. DBM application
indicate that the future turbine venting plan at Mountain Island will meet all state DO standards
at the reservoir conditions observed in the past.
124

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 36
FREQUENCY OF COMPLIANCE WITH INSTANTANEOUS DISSOLVED OXYGEN
STATE WATER QUALITY STANDARDS (4.0 MG/L) FOR HOURLY DISSOLVED
OXYGEN CONCENTRATIONS AT MOUNTAIN ISLAND CALCULATED FROM
DISCRETE BUBBLE MODEL IN COMPARISON TO THE HISTORICAL RECORD
12
ffl
Cz
0
H
d
Mountain Island
Total Number of Hours = 9264
-------------;------',, -------- ------- ------- ------- ------- - - - - --
——— — — — — —— — — — — —— —— — — — — —, —
——————————————— — — — — —'I — — ''"no,,,�,' —— — — — — 'I — — — — — —
w�,
r Instantaneous DO standard
- - - - - Hourly with aeration - -
Hourly without aeration
10 20 0 40 50 60 70
Frequency Exceeding DO Concentration ( %)
125
80 90 100

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 37
COMPARISON OF HOURS OF NON - COMPLIANCE AT MOUNTAIN ISLAND TO
INSTANTANEOUS DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS
(4.0 MG/L) FOR HOURLY DISSOLVED OXYGEN CONCENTRATIONS
CALCULATED FROM DISCRETE BUBBLE MODEL AND THE HISTORICAL
RECORD
10,000
1,000
FF�0-I
F-I
0 100
3-i
10
1
Mountain Island
Total Number of Hours = 9264
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-I - - - - - - -
I I I
- - - - - - - - } - - - - - - - -I-
_ - - - - - - - -I- - - - - - - -
-I- - - - - - - - - - - - - - - - -I- - - - - - - -
- - - - - - - -I- - - - - - - - - - - - - - - -I- - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
I I I
I I I
_ - - - - - - - -I- - - - - - - -
- - - Instantaneous DO standard - - - -
- - - - - Hourly with aeration - _ _ _
- - - - Hourly without aeration - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
I= - - - - - - - - - - - - - - - - 1
- r - - - - - - - - - - - - Y - - - - - - - -
I
-I- - - - - - - - - - - - - - - - -
- L -
- - - - - - - - - - - - - - -I- - - - - - - - - - - - - - - -
I I
I I
- - - - - _ - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - -1- - - - - - - - - - - - - - - -
1
- - - - - - - - - - - - - - - -I - - - - - - - - _ - - - - - - - -
I I
I I
- - - - - - - - - - - - - -I- - - - - - - - T - - - - - - - -
__ ______ ___________ _ _ _ __
- -_ - _ ---
-I - - -
------- - - - - - - - - - - - - -
- ---------
- - - - - - - - - - - - - - - -I- - - - - - - - r - - - - - - - -
1 2 3 4 5 6
DO Concentration (mg /L)
126
7 K

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 38
FREQUENCY OF COMPLIANCE WITH DAILY AVERAGE DISSOLVED OXYGEN
STATE WATER QUALITY STANDARDS (5.0 MG/L) FOR DAILY AVERAGE
DISSOLVED OXYGEN CONCENTRATIONS AT MOUNTAIN ISLAND
CALCULATED FROM DISCRETE BUBBLE MODEL IN COMPARISON TO THE
HISTORICAL RECORD
12
M
� 8
O
z
Cz
6
N
O
U
O 4
Q
Mountain Island
Total Number of Days = 1948
-- - - - - - - - - - - -, ----,- �-,-------,----------------------------- - - - - --
—— — — — —il ——————T————————————————————————————————————°'—"n"""mrt,,,,,,,———————————
i
Daily average DO standard
- - - -- T ------------------------- - - - - -- - - - - --
Daily average with aeration
Daily average without aeration
10 20 30 40 50 60 70
Frequency Exceeding DO Concentration ( %)
127
80 90 100

Section 5 Water Quality Assessment and Improvements — Individual Developments
FIGURE 39
COMPARISON OF DAYS OF NON - COMPLIANCE AT MOUNTAIN ISLAND TO
DAILY AVERAGE DISSOLVED OXYGEN STATE WATER QUALITY STANDARDS
(5.0 MG/L) CALCULATED FROM DISCRETE BUBBLE MODEL AND THE
Cn
Q
O
N
%/
LM
M
HISTORICAL RECORD
Mountain Island
Total Number of Days = 1948
--------- - - - - -- ------
--------'--------------- L----------------------- L - - -, j' ° "-- - - - - --
---------- - - - - -- L -
--------- - - - - - - - - - - - -- L - '-------- - - - - --
-- - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - -
- - - - -- - - - - - -- -----------------
- - - - - - -i-------- y -------- r -------- - - - - - - - - -. - - - - - r --------
-
- - - - - - -i-------- - - - - - - - - -------- - - - - - - - - - - - - - - - - - - - - - -il - - - - - - - -
- - - - - - -i- - - - - - - - - - - - - - - - i- - - - - - - - -i- - - - - - - - - - .... - - - - - - - - - - -il - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - r - - - - - - - - r - - - - - - - - - - - - - r - - - - - - - - r - - - - - - - -
- - - - - - - - - - - - - - - r - - - - - - - - r - - - - - - - - - - - - - - - - - - - - - - - - r - - - - - - - - - - - - - - - - -
T_ - - - - - - - -i- - - - - - - - - - -
- - - - - - - - - - - - r - ------------------ - - - - - - - - -------- ------ -------- -- - - - - - - -
-- - - - - - - ------------------------- - - - - -- - ------i----------------
-- - - - - - -
-- - - - - -- -------- L------- - - - - -- - -----i--------
- - - - - - - -
- - - - - - - -------- r -------- - - - - - r -------- - - - - - - -. - - - - - - - r -------- - - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-'- - - - - - - - - - - - - - - - - - - - - - - L - - - - - - - -
- -- Daihv average 1)() standard - - - - - - - - - -- --- - - - -'� ---- - - - -'- -- - - - - --
- -- T -- - - - - - - - -' - - - - - - -+- - - - - - - -
--- - - - - --
Daily average Nvith aeration
- - - - - - - - - - - - - - r - - - - - - - - -
Daily average without aeration
2 ; 4 5 6 7 8
DO Concentration (mg/L)
5.6.4.2 Resource Enhancement - Existing Use Standards
According to the NCDENR -NCDWQ Surface Waters and Wetlands Standards (2007) Standards
for Class C Waters and higher classifications, "the haters shall be suitable for aquatic life
propagation and maintenance Of biological integrity, lvildh/e, secondary recreation, and
agriculture. Sources of water quality pollution which preclude any of these uses on either a
short-term or long -term basis shall be considered to be violating a hater quality standard." This
is the applicable "existing use" water quality standard for hydroelectric operations and addresses
128

Section 5 Water Quality Assessment and Improvements — Individual Developments
the need for any receiving waters to be of suitable quality to provide for appropriate aquatic
communities.
As previously described the Mountain Island Development consists of an impoundment, a
bypassed reach, and tailwater which releases into the reservoir of Lake Wylie which is the next
downstream impoundment. Negotiations with stakeholders indicated that there were multiple
resource management objectives for the Mountain Island Development. A complicating factor
was the presence of the federally listed Schweinitz's sunflower in the Mountain Island Bypassed
Reach. Primarily these resource enhancement goals included:
■ Warmwater fishery and freshwater mussel enhancement (Bypassed Reach)
■ Schweinitz's sunflower maintenance and /or enhancement
■ Reservoir fishery maintenance and /or enhancement
Based on CHEOPS analyses and negotiations with stakeholders the consensus decision was
reached to provide mitigation for not meeting state resource agency aquatic habitat goals in the
Mountain Island Bypassed Reach. The CRA provides mitigation for the Mountain Island
Bypassed Reach (see Section 6 [Flow Mitigation Package] of this SIP) and monitoring and
protection of the Schweinitz's sunflower colony.
At "lake -to -lake" tailraces (Rhodhiss, Lookout Shoals, Cowans Ford, Mountain Island, Fishing
Creek, Great Falls /Dearborn, and Rocky Creek/Cedar Creek), the downstream reservoir backs up
into the powerhouse tailrace. At these lake -to -lake locations, the tailwater character will remain
lacustrine in nature and would not reasonably be expected to change in nature under minimum
continuous flows that are more appropriately intended to enhance riverine aquatic habitat.
However, the reservoir headwater in the vicinity of the hydro tailrace may benefit from DO
enhancements.
129

Section 5 Water Quality Assessment and Improvements — Individual Developments
5.6.5 Evaluation of Potential Reservoir Impacts Resulting from Altering Historic
Flows
Please refer to Section 7.2 (Assessments of Operating Scenarios).
5.7 Wylie Development in North Carolina
5.7.1 North Carolina DWQ Assessments and Water Quality Standards
The North Carolina portion of Lake Wylie (4019.6 ac) was classified as eutrophic. Most of the
Lake Wylie watershed is rapidly converting from forest/agriculture to urban development. DO
levels greater than 120 percent are common, nutrient concentrations ranged from moderate levels
to particularly high levels in Crowders Creek arm. Phosphorous levels in the Catawba Creek
arm improved with the decommissioning of the Catawba Creek WWTP.
To address eutrophication in Lake Wylie, NCDWQ and South Carolina DIAEC developed a
nutrient control strategy for the Lake Wylie watershed. In 1991, the USEPA approved a Lake
Wylie TMDL, including the point source allocation included in the Lake Wylie Nutrient
Management Plan.
Impaired waters inside the project boundaries:
■ 4,019.6 acres of Lake Wylie (North Carolina): biological impairment, excess sediment and
nutrients
Impaired waters outside the project boundaries that potentially influence water quality within the
project include:
■ North Carolina 303(d) listings for inflows to Lake Wylie were:
— Dutchman's Creek watershed - 3.2 miles of Killian Creek: biological impairment,
reduced flows
130

Section 5 Water Quality Assessment and Improvements — Individual Developments
— 113 miles of Long Creek: biological and recreational impairment, rapid
urbanization increased turbidity and manganese from runoff, constriction, and
agriculture
— 37.3 miles of South Fork watershed - 16.1 miles of Clark Creek (fecal coliforms,
copper, turbidity), 10.3 miles of Henry Fork (sediment), 6.0 miles of Indian Creek
(unknown), 4.9 miles of Maiden Creek (unknown), 4.3 miles of Mauney Creek
(point and non - point)
— 13.8 miles of Crowders Creek - 1.8 miles Abernathy Creek (biological impairment -
storm runoff, lithium processing), 12.1 miles Crowders Creek (biological and
recreational impairment)
— 13.4 miles of Catawba Creek: biological impairment
Numerical and existing use assessments are presented in the South Carolina 401 Certification
Application Package Section 5.1. An assessment of operational scenarios on Lake Wylie,
including the North Carolina portion of the lake is presented in Section 7.2 of this SIP.
131

Section 6
Flow Mitigation Package
Sections 4.5 and 4.6 of the Catawba - Wateree CRA state that Duke will mitigate for unavoidable
Project impacts by establishing 100 - foot -wide conservation easements along the Catawba,
Linville, and Johns rivers, as well as tributaries to the Catawba River. The process and
guidelines utilized in developing this mitigation package is described below.
The Aquatics Resource Committee developed continuous minimum flow releases to support and
enhance aquatic habitat needs. The methodology employed and processes are thoroughly
described in Section 5.6 of the CRA Explanatory Statement and in the Protection, Mitigation,
and Enhancement (PM &E) Measures Module found in the License Application. At the
conclusion of this process, flows in the following stream and river segments were identified as
not fully meeting resource agency resource objectives and, therefore, mitigation is being
provided.
TABLE 26
FLOW MITIGATION NEEDS
Impact location
Length (ft)
Total (ft)
Stream vs River
Paddy Creek Bypassed
Reach
4,050
4,050
Stream
Oxford Regulated River
Reach*
16,393 feet times 0.59 (correction
for fraction of flow)
9,672
River
Lookout Shoals Regulated
River Reach
1,929
1,929
River
Mountain Island Lake
Bypassed Reach
1,689
1,689
River
Total
4,050
Stream
13,290
River
* Flows to be provided at the Oxford Regulated River Reach will support 41% of the targeted habitat.
Therefore, the NCDENR agreed that the mitigation needs would be adjusted to account for this partial
meeting of habitat needs.
Duke, the NCDENR, and the North Carolina Wildlife Resources Commission (NCWRC)
worked cooperatively to develop an appropriate mitigation package. This group utilized
NCDENR's "Stream Mitigation for FERC - related 401 Certifications Internal DWQ Guidance"
1 32

Section 6 Floe Mitigation Package
(January 9, 2006) to guide its discussions. These guidelines are consistent with the US Army
Corps of Engineers' stream mitigation guidelines.
The focus of the team developing the mitigation package was on the preservation of wooded
stream buffers. Depending on the width of the buffer preserved, different amounts of mitigation
credits were available. Additional mitigation credit was also available if an entire watershed was
protected. The amounts of credit provided by each linear foot of buffer are provided below. It
should be noted that the formulas below are based upon the protection of both banks of a stream.
In the event that only one bank was protected, the credit was divided in half. In addition,
mitigation areas had to be along stream reaches of comparable size (i.e., +/- 1 stream order). In
other words, protecting a buffer along a 1st order tributary stream could not mitigate impacts to a
5th order river.
TABLE 27
MITIGATION RATIOS
Type of Preservation
Mitigation Ratio
(linear ft preserved: credit)
50- foot -wide buffers
5:1
100 - foot -wide buffers
4:1
Watershed preservation
3:1
Given these constraints, developing a mitigation package presented a significant challenge.
However, the team ultimately identified potential 100 - foot -wide conservation easements along
the Catawba River, the Johns River, the Linville River, and tributaries to the Catawba River to
mitigate for impacts. Subsequent to the submittal of the Application for a New License, Duke
acquired property rights that will enable it to provide permanent conservation easements as
outlined in Tables 26 and 27 below.
133

Section 6 Flow Mitigation Package
TABLE 28
RIVER MITIGATION CREDIT CALCULATIONS
Description
Easement
Mitigation Factor
Streambank factor (Divide
Mitigation
Length (ft)
(Divide by 4 for 100-
by two if only one side
credits (ft)
ft wide easements, 5
included)
credit (ft)
for 50 -ft)
including only one side)
Old Catawba River
17,884
4
2
2,236
Bridgewater Regulated
41,189
4
2
5,149
River Reach (RRR)
Bridgewater RRR (75-
647
4.5
2
72
foot -wide easements)
Johns River
49,056
4
2
6,132
Johns River (50 -foot-
988
5
2
99
wide easements)
13,921
4
2
1,740
Catawba River
4,260
4
2
1 533
Total
I 14,221*
* 14,221 feet of credits surpasses the need for mitigation credits of 13,290 feet.
TABLE 29
STREAM MITIGATION CREDIT CALCULATIONS
Description
Stream Length
Mitigation Factor
Streambank factor (1 if
Final stream
(ft)
(Divide by 4 if 100 -ft
including both sides of
mitigation
wide easement or by
stream; divide by two if
credit (ft)
3 if watershed
including only one side)
protection)
North Bend Recreation
8,069
3
1
2,690
Land
North Bend Recreation
5,661
4
2
708
Land
Catawba- Linville
7,832
4
2
979
Confluence
Paddv Creek Recreation
13,921
4
2
1,740
Lands
Total
6,117*
*6,117 feet of credits surpasses the need for mitigation credits of 4,050 feet.
Figures 40 through 44 depict river and stream shoreline easements used for flow mitigation
purposes on the Catawba - Wateree Project.
134

Section 6 Floe Mitigation Package
FIGURE 40
EASEMENTS ON THE LINVILLE AND CATAWBA RIVERS AND ASSOCIATED
TRIBUTARIES USED FOR FLOW MITIGATION
135

Section 6 Floe Mitigation Package
FIGURE 41
EASEMENTS ON THE CATAWBA RIVER IN THE BRIDGEWATER REGULATED
RIVER REACH USED FOR FLOW MITIGATION
136

Section 6 Floe Mitigation Package
FIGURE 42
EASEMENTS ON THE CATAWBA RIVER AND ASSOCIATED TRIBUTARIES IN
THE BRIDGEWATER REGULATED RIVER REACH USED FOR FLOW
MITIGATION
137

Section 6 Floe Mitigation Package
FIGURE 43
EASEMENTS ON THE JOHNS RIVER IN THE BRIDGEWATER REGULATED
RIVER REACH USED FOR FLOW MITIGATION
138

Section 6 Floe Mitigation Package
FIGURE 44
EASEMENTS ON THE CATAWBA RIVER DOWNSTREAM OF THE LOOKOUT
SHOALS DEVELOPMENT USED FOR FLOW MITIGATION
139

Section 7
Sustainability of the CRA
The CRA represents a well- vetted robust operating license proposal, which has a positive overall
impact on the resources and water quality of the Catawba and Wateree rivers. Duke has agreed
to a flow and water quality implementation plan with an aggressive schedule designed to
implement water quality enhancements as soon as feasible after the issuance of a New License
and in some cases enhancements will be implemented prior to the issuance of a New License.
The CRA includes other provisions that, while not direct water quality compliance provisions do
provide additional long -term sustainability and stability along with an overall positive effect on
the water quality and associated uses within the Catawba and Wateree rivers. In order to
accomplish this long -term sustainability, there were numerous studies and assessments
conducted by Duke and other stakeholders to provide insight and predictive capabilities for the
Project. Following is a summary of these activities and the results that were achieved.
7.1 Additional Features of the CRA
7. 1.1 Water Quality Management
■ Buffers and Key Land Purchases: Duke deposited $932 million into escrow accounts in
January 2007 per CRA Section 14.5.3.3 to support the purchase of land in the Catawba-
Wateree River Basin by the states of North Carolina and South Carolina for public
recreation, gamelands and /or compatible permanent conservation including water quality
protection. Both states responded to this opportunity with North Carolina using $3.8
million towards the purchase of approximately 2,800 acres near Lake Rhodhiss known as
the Johns River Gamelands Tract. This purchase preserved a significant portion of the
Johns River Watershed. South Carolina used $532 million towards the purchase of
approximately 1,878 acres on the east side of Lake Wateree known as the McDowell Creek
Tract. This tract contains 6 miles of protective easements on Lake Wateree and 2.5 bank
miles of easements on tributary streams.
140

Section 7 Sustainabilit-v of the CRA
The South Carolina Department of Natural Resources purchased from Crescent Resources
the 1,540 -acre Heritage Tract in the Great Falls area featuring protective easements put in
place by Duke. These conservation easements fulfill 2 miles of the Mitigation Plan
protective easements called for in CRA Section 4.6.1.
■ Shoreline Management Classifications and Guidelines: Duke has made significant
modifications to its existing shoreline management classifications, lake use restrictions,
and Shoreline Management Guidelines (SMG) in response to stakeholder interests and has
implemented these improvements in advance of receiving a New License.
■ Memorandum of Understanding: Duke has also offered to enter into a Memorandum of
Understanding with municipalities, counties and states to improve data sharing, buffer
enforcement, permitting reviews and scope of authority delineations.
■ Upper Catawba Public Access, Open Space, and Trails Agreement: As required by the
CRA, on April 30, 2008, NCDENR, Duke, and Crescent Resources signed an agreement
that provides new trail easements through some of the conservation easements along the
Catawba River and Warrior Fork in Burke County and the John River in Caldwell County.
The key component of the Agreement provides NCDENR or its designee the opportunity
to purchase almost 2,600 acres of lands predominately along the scenic Johns River in
Burke County, with some parcels along the Johns and Wilson Creek in Caldwell County.
Duke Ventures, a wholly owned subsidiary of Duke Energy, will acquire the properties
from Crescent by June 30, 2008, and provide roughly 3-4 years for NCDENR to obtain
funds from grants and other sources to acquire the lands. Land Purchase Options between
The State of North Carolina and Duke Ventures will be finalized by March 1, 2009. Duke
Ventures will reduce the purchase price by $1,350 per acre, up to a total of $3.5 million if
all tracts are purchased. The acquisition of these 2,600 acres of riverine floodplains and
uplands will help preserve a functional ecological corridor between the Johns River
Gamelands at the confluence of the Johns and Catawba rivers upstream to Wilson Creek
Gorge and the Appalachian Mountains.
141

Section 7 Sustainabilit-v of the CRA
■ 50 -Year License Provisions: CRA Parties agreed to the following additional resource
enhancements in the event that the FERC issues a 50 -year New License for the Project.
— Duke shall establish permanent conservation easements on approximately 12.5 total
bank miles (approximately 150 total acres) of selected tributaries to the Johns River.
— Duke shall contribute an additional $1.5 million for land conservation.
— Duke shall establish permanent conservation easements on approximately 5.5 total
bank miles (approximately 67 total acres) of selected portions of McDowell Creek,
Cedar Creek, and Rocky Creek, and their tributaries, all of which are tributaries to
Lake Wateree.
— Duke shall establish permanent conservation easements, restrictive covenants, or a
combination of the two, on the east shoreline of Lake Wateree from the downstream
boundary of Cedar Creek Access Area to a point approximately 4.7 shoreline miles
(as measured along the full pond contour) downstream. These conservation
easements and /or restrictive covenants will provide land conservation support on a
corridor extending 100 feet horizontally and upland from the full pond contour (total
of approximately 57 acres).
— Duke shall contribute an additional $1.5 million for land conservation.
7.1.2 Resource Management
■ Rare, Threatened, and Endangered Species: Duke will enter into formal species protection
plans for the monitoring, management and protection of federal and state listed species
including Rocky Shoals spider lily, Schweinitz's sunflower, dwarf - flowered heartleaf, bald
eagle, shortnose sturgeon, and mussels. Duke will also make monetary contributions to the
existing North Carolina and South Carolina Habitat Enhancement Programs.
■ Cultural and Archeological Resources: A Historic Properties Management Plan will be
implemented for future management of historic properties, powerhouse properties, and for
future consultation with Native American tribes and state historic resource agencies.
Important cultural and sacred properties are being leased to state resource agencies and to
142

Section 7 Sustainabilit-v of the CRA
the Catawba Indian Nation. The CRA also provides monetary support for initiatives at
numerous historic sites.
7.1.3 Water Quantity Management
■ Water Supply Studer This study documented the current water withdrawals and flow
returns affecting the operation of the Project and developed long -term (50 -year)
projections of water withdrawals and flow returns based on established growth projections.
The study also determined the safe yield (a risk parameter that is of particular interest to
public water system operators) of the Project's reservoirs. This is the only comprehensive
water supply inventory and assessment that exists for the Catawba - Wateree River Basin
covering both North Carolina and South Carolina. Results of this study were used as key
input to the basin -wide hydraulic modeling used to validate the long -term feasibility of the
operating proposals in the CRA.
■ Interbasin transfers: Stakeholders are extremely concerned about the current and projected
future amount of water being withdrawn from the Catawba - Wateree River Basin to be
transferred to adjacent basins and not returned to the Catawba - Wateree River Basin.
Projected growth in inter -basin transfers was included in future water demand projections.
However, neither the CRA nor this application comprehensively assess nor take a position
on the approval of such future requests.
■ Low Inflow Protocol /Critical habitat flows: A basin -wide LIP has been developed to
balance water uses and to extend useable water storage as drought conditions emerge and
intensify. The LIP establishes trigger points and procedures for aggressively reducing flow
releases from the Project and other water demands during periods of low inflow. The LIP
plays a significant role over the anticipated term of the New License in extending the
available water supply when there is insufficient inflow to meet the normal demands and it
is a major factor in achieving workable and sustainable lake levels and flow releases. In
fact, the coordinated implementation of the LIP is expected to extend the point at which
safe yields are reached for water supply intakes by a decade or more. Critical low lake
143

Section 7 Sustainabilit-v of the CRA
levels and critical low flow releases provide a safety net of protection for reservoir and
riverine aquatic habitat, water withdrawer intake and discharge needs during low flow
periods that has never existed before. The CRA also creates a Catawba - Wateree Drought
Management Advisory Group to convene and coordinate actions in response to dry periods
and droughts. The CRA also establishes a Water Management Group whereby Duke and
Public Water System owners will pool their resources to tackle initiatives that will protect
the water quantity and water quality in the Basin.
■ Recreation Flow Releases: Dedicated recreation flows will be released at rates and on
schedules that support paddling, wade fishing, boat fishing, and other activities such as
duck hunting. These new scheduled flows will be provided in the four primary regulated
river reaches as will canoeing and whitewater releases into the Great Falls Bypasses
Reaches.
7.2 Assessments of Operational Scenarios
Duke combined years of historical water quality monitoring records with supplemental water
quality sampling conducted in 2004 to develop and calibrate hydrodynamic and water quality
computer models of the tailrace and the downstream riverine systems (River Management
System) and reservoirs (CE- QUAL -W2). These models have been utilized individually and
collectively to assist stakeholder deliberations by predicting the downstream temperatures and
DO concentrations (and transport of other water quality constituents) under a variety of Project
operating conditions, which is beyond the capability of empirical data collection. The models
have been used to quantify the extent of Project influence and non -point (nutrient) influence on
downstream water quality, to evaluate feasible alternative operating or engineering scenarios,
and to determine the water quality implications of certain aquatic in- stream flow proposals and
low -inflow situations.
These models were used to evaluate the effect of the Project operations proposed in the CRA on
a series of performance metrics for several reservoirs in the Catawba - Wateree River Basin (Lake
James, Lake Hickory, Lake Norman, Lake Wylie, Lake Wateree, and Fishing Creek Reservoir).
144

Section 7 Sustainabilit-v of the CRA
The results of proposed future operation per the CRA were compared to those of current -day
operations.
Water quality model results enable a relative comparison of whether proposed future CRA
operations may be expected to have an enhancing, degrading, or neutral influence on various
reservoir parameters. This assessment supplements the required tailwater water quality
certification assessments by examining parameters that are not directly addressed by water
quality standards and existing uses in the hydro station tailraces and riverine sections. The
following metric comparisons were selected by the stakeholders comprising the Water Quality
Resource Committee. Metrics are shown as "no significant impact' when the result of CRA
operations and current day operations differ by less than 5 percent. Where N/A appears, it
indicates that stakeholders did not request that the parameter be evaluated at that location.
Overall these reservoir metrics improve slightly under the future operation of the Project
proposed in the CRA. Most metrics (16) remain unchanged and exert no degrading influence on
the chosen parameters. There are an equal number of significant enhancing influences (7) as
there are degrading influences (7). However, the enhancing influences predominantly occur
during normal flow years and by virtue of time would be expected to outweigh the degrading
influences that all occur more infrequently during low flow years.
145

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I

Section 8
Summary and Conclusions
According to state water quality certification regulations, a water quality certification should be
issued for any project discharging to surface waters that meets established state criteria. The
following criteria are intended to reflect the considerations and requirements that would have to
be addressed to the satisfaction of both North Carolina and South Carolina water quality
agencies. The subject of this certification and therefore of this evaluation is the continued
operation of the Project under a New License issued by the Federal Energy Regulatory
Commission that is consistent with the applicable sections (refer to Section 3.5 of this SIP) of the
CRA for the Project. This section addresses this application's compliance with each criterion.
1. The project is water dependent and has no feasible /practical alternative.
The continued operation of the Project has no practical alternative. Fourteen counties and more
than 30 municipalities depend now and in the future on the following critical benefits provided
by the Project that cannot be practically replaced:
■ Energy: In addition to currently providing the energy to power 116,000 homes (on an
average yearly basis) and water to support over 8,100 megawatts (MW) of fossil and
nuclear - fueled power plants (44 percent of Duke's North Carolina and South Carolina
generating fleet), the Project is a critical component in meeting future electric supply
needs. Duke's system demand for electricity in North Carolina and South Carolina is
expected to more than double over the next 50 years and a substantial portion of that new
generation capacity is expected to rely on the Project.
■ Drinking Water: The Project provides a reliable drinking water supply for over 13 million
people. Future public water supply needs are projected to increase over 200 percent in the
next 50 years.
■ Jobs: The Project also provides a reliable water supply that is vital to the operations of
several large industrial facilities, a key component to the economic vitality of the region.
149

Section 8 Summan- and Conclusions
2. The project will minimize adverse impacts to the surface waters based on
consideration of existing topography, vegetation, fish and wildlife resources, and
hydrological conditions.
As further elaborated upon in Section 5 of this SIP and in Items 3 through 6 below, there are
expected to be no adverse impacts to existing uses resulting from continued operation of the
Project under a New License consistent with applicable sections of the CRA.
3. The project does not result in the degradation of groundwater or surface waters.
Where surface water quality exceeds levels necessary to support propagation of fish, wildlife,
and recreation in and on the water, that quality is not allowed to be degraded below the level
needed to maintain the existing uses that those waters currently support and the anticipated uses
of those waters.
No losses of existing uses are anticipated when operating the Project under a New License
consistent with applicable sections of the CRA. At almost all locations, water quality
enhancements, higher continuous flows, drought management (LIP), SMP enhancements, and
the incorporation of future water supply needs all serve to enhance and protect existing uses.
Since all existing uses are enhanced except for three locations (please refer to Item 6 below)
where existing uses are unchanged, there is no expected degradation in existing uses.
Please refer to Item 5 that follows. The measures that are proposed to be implemented by the
applicant will enhance water quality and meet downstream water quality standards in the future.
No degradation of existing water quality is expected to occur.
150

Section 8 Summan- and Conclusions
4. The project does not result in cumulative impacts, based upon past or reasonably
anticipated future impacts, which cause or will cause a violation of downstream water
quality standards.
The objective of a cumulative impact assessment is to determine whether the impacts resulting
from the continued operation of the Project under a New License from the Federal Energy
Regulatory Commission and in accordance with the applicable sections of the CRA, when added
to other past, present or reasonably anticipated future impacts, cause or will cause a violation of
downstream water quality standards.
The nature of the new equipment implementations and operational modifications presented in the
CRA and in Table 4 of the application form in order to deliver the agreed -upon higher minimum
continuous flows and to meet water quality standards for DO all serve to enhance (raise) DO
concentrations. The proposed future operation of the Project is not projected to diminish water
quality, thus, there is no scenario in which reasonably anticipated future water quality impacts
could be further diminished via combining with the water quality enhancements resulting from
operating the Project per applicable sections of the CRA.
Duke and other Catawba - Wateree stakeholders have incorporated the following reasonably
anticipated future impacts into their studies, modeling and deliberations to insure that these
future events have been considered and that the CRA is resilient in the event of these
occurrences:
■ Future (50 -year) public water needs estimate
■ Future new power generation water needs estimate
■ Potential future inter -basin transfer water requests
■ Potential future droughts
151

Section 8 Summan- and Conclusions
5. The project provides for protection of downstream water quality standards with on-
site stormwater control measures.
Other than constricting a new powerhouse at the Bridgewater Development, this application
does not contemplate land - disturbing activities or constriction (dredging or filling) work within
the waters of the Project. The implementation of water quality related equipment modifications
will begin upon receiving certifications from North Carolina and South Carolina and a New
License from the FERC. Therefore, stormwater control measures are not applicable for this
application. Necessary constriction- related permits and certifications for the new Bridgewater
Powerhouse constriction project as well as any other activities requiring dredge or fill permits to
implement other provisions of the CRA will be applied for separately.
Table 4 of the 401 Water Quality Certification Application summarizes the measures that are
proposed to be implemented by the applicant to enhance water quality and meet downstream
water quality standards in the future. The projected result of implementing these modifications
and assessment of compliance with state standards is presented in Section 5 of this SIP for each
hydro station.
Sections 4 and 5 of this SIP provide reasonable assurance that all stations are projected to meet
state water quality standards for DO.
6. The project provides for replacement of existing uses through mitigation.
No losses of existing uses are anticipated when operating the Project under a New License
consistent with applicable sections of the CRA.
At almost all locations, water quality enhancements, higher continuous flows, drought
management (LIP), shoreline management plan enhancements, and the incorporation of future
water supply needs all serve to enhance and protect all existing uses.
152

Section 8 Summan- and Conclusions
There are only three locations in the Project where no operational changes are proposed and for
which existing uses will remain unaltered.
■ Paddy Creels Bypassed Reach: This creels (0.7 mile long) flows from the Paddy Creels
Dam at Lake James into the Catawba River Bypassed Reach. Stakeholders toured the
Catawba River and Paddy Creek bypassed reaches and observed that the Paddy Creek
channel has been severely impacted by high tropical storm spill flows to the point that the
potential for significant aquatic habitat restoration is low. The Aquatics Resource
Committee agreed to a) not invest in the high implementation cost required to deliver flow
into this creek for a speculative gain, b) instead focus on maximizing habitat in the higher
priority Catawba River Bypassed Reach and the river below the Bridgewater Powerhouse,
and c) fully mitigate for the aquatic habitat not realized in Paddy Creek.
■ Mountain Island Bypassed Reach: This bypass (03 mile long) is unique in that a large
colony of a federally - listed endangered species, the Schweinitz's sunflower, has become
established in the bypass channel. The current habitat in this location supports this species.
Due to the short length of this bypass and in order to not alter the habitat supporting this
rare sunflower species, stakeholders agreed to not introduce higher flow releases and to
fully mitigate for the aquatic habitat not realized in the Mountain Island Bypassed Reach.
■ Wateree Spillway Channel: Flow through the Wateree Powerhouse is released into an
excavated channel that nuns roughly parallel to the original Wateree River channel at the
base of Wateree Dam. The original channel (0.4 mile long) receives intermittent inundation
from powerhouse flow releases and spills over the Wateree Dam, but its flow regime is
significantly altered. Releasing continuous flows (especially high spring spawning flows)
into this channel rather than through the generators is a significant hydroelectric energy
generation (an existing use) impact to Duke. Alternatively, providing flows into the
channel in addition to powerhouse releases can at times strain the water storage in the
Catawba - Wateree River Basin. For these reasons plus the fact that this channel carries no
unique Critical Habitat designations for shortnose sturgeon or any other rare, threatened, or
153

Section 8 Summan- and Conclusions
endangered species, stakeholders agreed to not introduce higher flow releases and to fully
mitigate for the aquatic habitat not realized in the Wateree Spillway Channel.
There are three locations in the Project where flow and water quality enhancements are proposed
to be made and existing uses are enhanced, but the level of enhancement does not fully meet the
goal of state and federal resource agencies.
At Oxford, significant expense and a high flow release would be required in order to completely
inundate the wide, braided tailrace channel. At Lookout Shoals, the length of the riverine section
below the hydro station varies significantly. If Lake Norman is near its high elevation, the
riverine section is very short. The maximum tailrace length does not exist but a few months out
of the year. In the Great Falls Long Bypassed Reach, a point of diminishing return was reached
such that beyond the flows currently proposed, very little additional wetted perimeter was gained
under significantly larger flow releases. Also, flows in the Great Falls Long Bypassed Reach
reduce electric generation (an existing use) at the Dearborn Powerhouse and higher flows would
exacerbate this loss even more. Stakeholders agreed to not introduce higher flow releases and to
mitigate for the portion of the aquatic habitat goal not realized at these locations.
At "lake -to -lake" tailraces (Rhodhiss, Cowans Ford, Mountain Island, Fishing Creek, Great
Falls /Dearborn, and Rocky Creek/Cedar Creek), the downstream reservoir backs up into the
powerhouse tailrace. At these lake -to -lake locations, the tailwater character will remain
lacustrine in nature and would not reasonably be expected to change in nature under minimum
continuous flows that are more appropriately intended to enhance riverine aquatic habitat.
However, the reservoir headwater in the vicinity of the hydro tailrace may benefit from DO
enhancements.
All existing uses are enhanced save for three locations where existing uses are unchanged
(unenhanced) and three locations where enhancements will be achieved but do not reach the
level of enhancement desired by resource agencies. In order to address these locations where
resource agency aquatic habitat goals may not be fully met, Duke has consulted with resource
agencies and per the CRA has agreed to provide mitigation. This mitigation complies with North
154

Section 8 Summan- and Conclusions
Carolina Department of Environment and Natural Resources Division of Water Quality guidance
document entitled Stream Mitigation for FERGrelated 401 Certifications, Internal DWQ
Guidance, NC Division of Water Quality. These guidelines are also consistent with the
USACOE Stream Mitigation Guidelines. This guidance document was used for both the North
Carolina and South Carolina mitigation packages (refer to CRA Sections 4.5 and 4.6). Details
regarding the application of this guidance document to the Project and the resulting mitigation
package requirements are found in Section 6 of this SIP.
As an additional enhancement not explicitly included in the mitigation packages, the CRA
includes that Duke will install new minimum flow aerating turbines at Wylie Hydro and Wateree
Hydro. These are multi - million dollar investments and will be made significantly before the
targeted turbines are due to be replaced. These investments will provide the steady flow releases
necessary to fully enhance an additional 5 miles (Wylie) to 7 miles ( Wateree) of stream habitat
immediately below each station. This is habitat that would not otherwise be fully enhanced under
pulsing operations utilizing the current turbines at these stations.
155

Section 9
References
Bales, J. D. and M. J. Giorgino. 1998. Lake Hickory, North Carolina: Analysis of Ambient
Conditions and Simulation of Hydrodynamics, Constituent Transport, and Water - Quality
Characteristics, 1993 -94. U. S. Geological Survey. Water - Resources Investigations
Report 98 -4149. Raleigh, NC.
Duke Energy. 2006. Catawba - Wateree Project FERC 42232 Application for New License
Exhibit E — Water Quantity, Quality, and Aquatic Resources, Study Reports. Duke
Energy. Charlotte, NC.
2007. Catawba - Wateree Project FERC 4 2232 Application for New License - Supplement
and Clarification. Book 2 of 10. Duke Energy. Charlotte, NC.
Duke Power. 2005. Catawba Hydros - Existing Aeration Capability and Downstream Aeration
Tests, Technical Report Series, Catawba - Wateree License. FERC 4 2232, Charlotte, NC.
Knight, J. 2003. Dissolved Oxygen Concentrations and Water Temperature from Bridgewater
Hydroelectric Station. Duke Power Company.
North Carolina Department of Environment and Natural Resources. 2004. Catawba River
Basinwide Water Quality Plan, Division of Water Quality Planning, Raleigh, NC.
2007. "Redbook ". Surface Waters and Wetlands Standards. 15A NCAC 02B.0211(2).
North Carolina Department of Environment, Health and Natural Resources and South Carolina
Department of Health and Environmental Control. 1992. Water Quality Investigation of
Lake Wylie, April 1989 — September 1990. Report No. 92 -04. North Carolina
Department of Environment, Health and Natural Resources, Raleigh, NC, and South
Carolina Department of Health and Environmental Control, Columbia, SC.
156

Section 9 References
North Carolina Division of Water Quality. 1995. Catawba River Basin -wide Water Quality
Management Plan. Division of Water Quality, North Carolina Department of
Environment and Natural Resources. Raleigh, NC.
1999. Catawba River Basin -wide Water Quality Plan, December 1999. Water Quality
Section, Division of Water Quality, North Carolina Department of Environment and
Natural Resources. Raleigh, NC.
2000. Water Quality Progress in North Carolina 1998 -1999 305(b) Report. Water
Quality Section, Division of Water Quality, North Carolina Department of Environment
and Natural Resources. Raleigh, NC.
2004. Catawba River Basinwide Water Quality Plan [Online] URL:
http: / /h20. enr. state /nc /us/ basinwide/ Draft2004CatawbaRiverBasinWaterQualityPlan .htm.
September 2004. (Accessed May 2008.)
South Carolina Department of Health and Environmental Control. 2000a. Catawba Basin
Watershed Water Quality Assessment, February 2000. Bureau of Water, South Carolina
Department of Health and Environmental Control. Columbia, SC.
2000b. The State of South Carolina Water Quality Assessment Pursuant to Section
305(b) of the Federal Clean Water Act, Fiscal Year 2000 Report. Bureau of Water, South
Carolina Department of Health and Environmental Control. Columbia, SC.
2000c. State of South Carolina Section 303(d) List for 2000. Bureau of Water, South
Carolina Department of Health and Environmental Control. Columbia, SC.
Wagner, R. J., H. C. Mattraw, G. F. Ritz, and R. A. Smith. 2000. Guidelines and Standard
Procedures for Continuous Water - Quality Monitors: Site Selection, Field Operation,
Calibration, Record Computation, and Reporting. U. S. Geological Survey, Water -
Resources Investigations Report 00 =4252. Reston, VA.
157

APPENDICES

APPENDIX A
QUALITY ASSURANCE PROJECT PLAN

Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
CATAWBA - WATEREE TAILWATER DISSOLVED OXYGEN
MONITORING
FERC PROJECT NO. 2232
QUALITY ASSURANCE PROJECT PLAN (QAPP)
DRAFT
Effective Date:
Revision No.
Duke
aftrEnergy.

Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
QUALITY ASSURANCE PROJECT PLAN
CATAWBA - WATEREE PROJECT, FERC No. 2232
Effective Date:
DOCUMENT APPROVAL PAGE
E. Mark Oakley
Duke Energy Relicensing Project Manager
S gnatilre
George A. Galleher
Duke Energy Quality Assurance Manager
S gnatilre
Carol Goolsby
Vice President, Hydro Fleet
S gnatilre
John Dorney, Program Development
North Carolina Division of Water Quality
S gnatilre
Heather Preston, Director
Water Quality Division
South Carolina Department of Health and Environmental Control
S gnatilre
Tyrus Ziegler
Field Monitoring Manager, Devine Tarbell and Associates
S gnatilre

Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
TABLE OF CONTENTS
GROUP A — PROJECT MANAGEMENT
A1.0
Distribution List ..................................................................................... ..............................1
A2.0
Project Organization .............................................................................. ..............................2
A3.0
Project Definition /Background .............................................................. ..............................3
A4.0
Project Task Description ........................................................................ ..............................6
A5.0
Quality Objectives and Criteria ............................................................. ..............................6
A6.0
Special Training / Certification ................................................................ ..............................7
A7.0
Documents and Records ........................................................................ ..............................7
GROUP B — DATA GENERATION AND ACQUISITION
131.0
Study Design .......................................................................................... ..............................8
B2.0
Sampling Methods ................................................................................ .............................32
B3.0
Sample Handling and Custody .............................................................. .............................33
B4.0
Analytical Methods ............................................................................... .............................33
B5.0
Quality Control ..................................................................................... .............................33
B6.0
Instrument/Equipment Testing, Inspection, and Maintenance ............. .............................33
B7.0
Instrument/Equipment Calibration and Frequency ............................... .............................33
B8.0
Inspection /Acceptance of Supplies and Consumables .......................... .............................34
B9.0
Non - Direct Measurements .................................................................... .............................34
1310.0
Data Management ................................................................................. .............................34
GROUP C — ASSESSMENT AND OVERSIGHT
C 1.0 Assessment and Response Actions ....................................................... .............................35
C2.0 Reports to Management ........................................................................ .............................35
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Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
GROUP D — DATA VALIDATION AND USABILITY
D1.0
Data Review, Verification, and Validation ...........................................
.............................35
D2.0
Verification and Validation Methods ....................................................
.............................36
D3.0
Reconciliation with User Requirements ...............................................
.............................36
REFERENCES................................................................................................. .............................37
APPENDICES
APPENDIX A -QAPP - Standard Operating Procedures for In -Situ Compliance monitoring
APPENDIX B -QAPP - Supplemental Trout Habitat Monitoring
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Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
LIST OF TABLES
Table 1: Contacts Receiving Duke Energy Catawba - Wateree QAPP ............ ............................... 1
Table 2: Water Quality Monitoring Schedule ................................................. ............................... 6
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Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
LIST OF FIGURES
Figure 1:
Program Organization Chart ........................................................... ...............................
3
Figure 2:
Catawba - Wateree Project Location Map ........................................ ...............................
5
Figure 3:
System Overview — this configuration will be provided at each hydro facility .............
9
Figure 4:
Schematic Drawing of the Catawba River .................................... ...............................
11
Figure 5:
Bridgewater Water Quality Monitoring Location ......................... ...............................
13
Figure 6:
Rhodhiss Water Quality Monitoring Location .............................. ...............................
15
Figure 7:
Oxford Water Quality Monitoring Location ................................. ...............................
16
Figure 8:
Lookout Shoals Water Quality Monitoring Location .................... ...............................
18
Figure 9:
Cowans Ford Water Quality Monitoring Location ........................ ...............................
19
Figure 10:
Mountain Island Water Quality Monitoring Location ................ ...............................
21
Figure 11:
Wylie Water Quality Monitoring Location ................................. ...............................
22
Figure 12:
Fishing Creek Water Quality Monitoring Location .................... ...............................
24
Figure 13:
Great Falls- Dearborn Water Quality Monitoring Location - Diversion Dam............
25
Figure 14:
Cedar Creek Water Quality Monitoring Locations ..................... ...............................
29
Figure 15:
Wateree Water Quality Monitoring Locations ............................ ...............................
31
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Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
GROUP A - PROJECT MANAGEMENT
A1.0 Distribution List
This Quality Assurance Project Plan (QAPP) will be distributed to the following agencies and
entities with an interest or role in water quality monitoring conducted by Duke Energy Carolinas,
LLC (Duke or Licensee) for the Catawba - Wateree Hydroelectric Project (FERC No. 2232).
Table 1: Contacts Receiving Duke Energy Catawba - Wateree QAPP
Dianne Reid
North Carolina Division of Water Quality
John Dorney
North Carolina Division of Water Quality
Heather Preston
South Carolina Department of Health and Environmental Control
Chuck Hightower
South Carolina Department of Health and Environmental Control
Rusty Wenerick
South Carolina Department of Health and Environmental Control
Ben West
U. S Environmental Protection Agency
Scott Holland
Duke Energy Corporation
Mark Oakley
Duke Energy Corporation
George Galleher
Duke Energy Corporation
Tyrus Ziegler
Devine Tarbell and Associates
Steve Johnson
Devine Tarbell and Associates
Jon Knight
Devine Tarbell and Associates

Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
A2.0 Project Organization
The Duke Energy Carolinas, LLC (Duke) Hydro Operations Compliance Engineer will serve as
the Project Manager (PM) and is responsible for overseeing all aspects of the continuous
dissolved oxygen (DO) monitoring program in the Catawba - Wateree Project tailwaters,
including oversight of the subcontractor collecting the data in accordance with the Water Quality
Monitoring Plan (WQMP) (Appendix A -QAPP) for the Project and this QAPP. The Duke PM is
responsible for reporting data to the North Carolina Division of Water Quality (NCDWQ) and
the South Carolina Department of Health and Environmental Control (SCDHEC) as described in
Section A4.
The Duke Hydro Operations Compliance Engineer also acts as the Project Quality Assurance
(QA) Manager and is responsible for maintaining the QAPP and Quality Assurance /Quality
Control (QA /QC) files. The Duke PM /QA Manager does not supervise or manage the personnel
responsible for collecting the data. The Duke PM/QA Manager is responsible for the final
review of documentation for the QA /QC file and that data collection is consistent with this
QAPP.
The Monitoring Field Manager (subcontractor) is responsible for the review of data and
supporting documentation prior to submittal to the Duke PM/QA Manager. The Monitoring
Field Manager is also responsible for directly overseeing the Monitoring Field Staff
(subcontractor) and the day -to -day coordination of field collection and equipment maintenance
in accordance with this QAPP, the Water Quality Monitoring Plan (WQMP) and all associated
Standard Operating Procedures (SOPS). The Monitoring Field Manager is responsible for
reporting any equipment/calibration issues to the Data Processor and for making decisions
related to corrective action related to equipment/calibration issues encountered by Monitoring
Field Staff. The Monitoring Field Manager also makes recommendations for flagging data that
may be affected due to known equipment/calibration issues.
The Monitoring Field Staff (subcontractor) are responsible for maintaining functioning
instruments, performing calibration procedures as required, collecting and downloading data, and
maintenance of field log books in accordance with this QAPP, the WQMP and all associated
SOPS. Field Staff are responsible for reporting any equipment/calibration issues to the
Monitoring Field Manager.
The Data Processor is responsible for the data that are processed into an annual database and
electronic spreadsheets. The Data Processor is responsible for software support and maintaining
the interface between the instruments and the receiving station, for reviewing selected portions of
the individual data files and for maintaining records of changes or flagging of data in the
database.
The organizational relationship of these functions is presented in Figure 1.
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Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Figure 1: Program Organization Chart
Duke
Project Manager /Quality
Assurance Manager
(PM /QA Manager)
Monitoring Field Manager
Data Processor (Subcontractor)
Monitoring Field Staff
(Subcontractor)
A3.0 Project Definition/Background
A3.1 Background
Duke Energy Carolinas, LLC (Duke) is applying for a new operating license from the Federal
Energy Regulatory Commission (FERC) for the Catawba - Wateree Hydro Project (all eleven
impoundments and thirteen powerhouses are included in the Catawba - Wateree License, see
Figure 2). Along with development of its license application, Duke has developed a
Comprehensive Relicensing Agreement (CRA) along with stakeholders to address many Project -
related issues.
One of the proposed license articles in the Application for New License stipulates a Flow and
Water Quality Implementation Plan (FWQIP) to enhance the aquatic resources by improving
flow conditions for fish and wildlife and by meeting state dissolved oxygen standards. Even
though Duke has previously modified many of the turbines to increase the capacity to aerate the
downstream releases, additional plant modifications are necessary to enhance the aeration
capacity and /or meet the minimum flow requirements stipulated in the CRA. The FWQIP
describes the additional physical modifications, the schedule for completion of the modifications,
and any interim measures prior to the physical installation of the equipment. This document is
available in Table 4 of the 401 Water Quality Certification Application.
An additional proposed article for the new license is the Water Quality Monitoring Plan
(WQMP). This proposed article describes a monitoring program at each hydroelectric station.
The WQMP discusses two major activities for water quality monitoring. The first activity is the
measurement and reporting of dissolved oxygen concentrations (DO) for the duration of the
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Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
license (this activity is the focus of this QAPP). The second activity is the measurement of
temperature and flow downstream of the Bridgewater project to verify the computer modeling
used to establish the flow release patterns into the bypassed reach and the downstream river
channel (discussed in Appendix B- QAPP).
The purpose of this QAPP is to provide a quality assurance /quality control program for the
proposed DO monitoring described in the WQMP. This QAPP documents the data collection
procedures and database management activities to ensure that valid data are used by Duke,
NCDWQ, and SCDHEC to evaluate compliance to state dissolved oxygen (DO) standards. This
QAPP was developed in accordance with the USEPA guidance document "Guidance for Quality
Assurance Project Plans, EPA QA /G -5" dated December 2002.
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Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Figure 2: Catawba - Wateree Project Location Map
LINCOLNTON
MT N. ISLAND LACE
MOOILL
LACE WATEREE
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Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
A3.2 Problem Statement
The goal of the Catawba - Wateree QAPP /WQMP is to provide quality, real -time dissolved
oxygen (DO) and temperature data for the project releases. This real -time data will be used by
operators to adjust hydro operations to maintain compliance with state DO standards and the
requirements of the FERC license. In addition, this data will be used for reporting compliance,
and /or non - compliance events to appropriate agencies, as well as conducting on -going
evaluations regarding equipment performance and operational guidelines.
A4.0 Project Task Description
Duke's Monitoring Field Staff will collect DO and water temperature data in accordance with the
WQMP. Table 2 summarizes the tasks anticipated to occur under the WQMP and this QAPP.
The QAPP will become effective upon final 401 Water Quality Certification by NCDWQ and
SCDHEC.
The following is a general schedule for the monitoring activities discussed here:
Table 2: Water Quality Monitoring Schedule
Task
Timeframe
Notes
Water Quality
12 months after FERC approves
At several locations, the installation of water quality
Monitor
the FWQIP (subject to approval
monitors will precede the installation of the equipment
installation
in NC and SC 401 Water
modifications necessary- to achieve compliance. In
Quality Certification) per CRA,
these cases, the monitors will assist Duke in the
Appendix M
implementation of interim measures per the FWQIP.
However, these monitor results are not suitable for
compliance assessments until the necessary equipment
modifications have been implemented (refer to CRA
Section 13.2)
DO
April 1— November 30
Each year for the term of the license, per
Monitoring
WQMP/FWQIP
Temperature
April 1- November 30
Each year for the term of the license, per
Monitoring
WQMP/FWQIP
Annual Report
June 30
The annual report will reflect previous year's data:
Submitted
annual reports submitted for the term of the license
A5.0 Quality Objectives and Criteria
The objectives of data measurement, collection, and retention are to provide real -time,
continuous information to hydro operators to ensure compliance with applicable State Water
Quality Standards and FERC license requirements and to provide historical information to
operators for continuous improvement of procedures and operations. The following
considerations are necessary that the DO sensor be:
a. representative of water quality conditions during all Project operations;
b. secure (minimize probability of vandalism);
c. accessible for maintenance at all flows; and;
d. at a distance downstream to achieve a small time -lag between changes in Project
operations and monitor response
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Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
e. maintained to enable a performance within the manufacture's stated accuracy
Calibrated and well maintained water quality sensors usually provide more accurate readings
than those given by the manufacturer. Routine maintenance and calibration of oxygen sensors is
critical since the DO probes are prone to fouling (biological and chemical), which typically
results in readings of lower DO concentrations than actually exist. The maintenance and
calibration procedures (see Section B7.0) are designed to keep the measurements well within the
limits specified by the manufacturer.
A6.0 Special Training /Certification
All personnel responsible for field monitoring must be familiar with this QAPP and the attached
Standard Operating Procedures (SOP).
The Monitoring Field Manager will review, and, if necessary, train the Monitoring Field Staff
prior to each monitoring season. The training will consist of:
• Current field procedures and SOPS,
• Changes, if any, from previous years, and
• Continuous improvement items identified from past data analysis.
The Monitoring Field Manager will observe the field techniques of the Field Staff at periodic
intervals throughout the monitoring season. Any issues with technique will be corrected at that
time and documented in the appropriate field log book.
All personnel responsible for field monitoring must complete safety training as required by
regulating agencies and Duke. Completion of this training will be required on an annual basis
will be documented. All training records will be maintained by the Duke PM/QA Manager.
A7.0 Documents and Records
All personnel with a role in implementing the WQMP will receive the most recently approved
QAPP and associated documents. These documents will be updated as necessary by the Duke
PM/QA Manager and distributed to all parties listed in Section Al. Any revisions to the QAPP
will be noted on the title page with the revision number and effective date. Only the Duke
PM/QA Manager will have access to making revisions to the electronic copy of the QAPP,
Duke's PM /QA manager is also responsible for obtaining appropriate revision approvals by
NCDWQ and SCDHEC and retention of all revisions to the QAPP.
Revisions to the QAPP may include but not limited to:
• Procedural changes due to continuous improvement activities identified throughout the
course of monitoring,
• Procedural changes due to technological changes and /or improvements,
• FERC License revisions or requirements, and
• Water quality agency revisions or requirements.
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Duke Energy Carolinas, LLC Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
As specified in the SOP's, during the monitoring season, the Monitoring Field Staff will:
• Maintain records of calibration,
• Maintain records of maintenance,
• Maintain records of instrument failure,
• Maintain records of corrective action, and
• Maintain any other field notes /information in field log books.
The field staff will transfer these records electronically to the Monitoring Field Manager on a
periodic basis as specified in the SOP's.
The Monitoring Field Manager will summarize all field staff records and monitoring data on a
periodic basis throughout the monitoring season. These electronic summaries will be reviewed
by the Field Manager and transferred to the Duke PM/QA Manager periodically throughout the
monitoring season. All original raw data records (paper and electronic) collected by the field
staff during the monitoring season will be transferred to the Duke PM/QA Manager at the end of
the monitoring season. The Duke PM /QA Manager will maintain copies of these records in the
QA /QC files for this monitoring project for the term of the Catawba - Wateree Project FERC
License.
The Monitoring Field Manager will maintain scans of all forms and all data files in electronic
format for five years. Access to these files is controlled by the Monitoring Field Manager.
All non - compliance communications and annual compliance reports submitted to NCDWQ and
SCDHEC (see Section A4) will also be maintained in hard copy and electronic format by the
Duke PM/QA Manager for the term of the new License.
Details of electronic data management are further described in Section B 10 of this QAPP.
GROUP B - DATA GENERATION AND ACQUISITION
B1.0 Study Design
The purpose of monitoring temperature and dissolved oxygen in the water released from the
hydro is to ensure that the DO concentration in that water meets or exceeds applicable state WQ
standards. The study design was based upon the work by Wagner et al. (2000) and modified to
meet specific monitoring objectives described in the License Application. The basic components
of the monitoring system are (1) sensors that measure the temperature and dissolved oxygen, (2)
a means of getting the sensor data to an appropriate database, and (3) a database capable of
meeting the operational and reporting requirements.
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Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Component Description
Tailwater Water Quality Monitor
The DO sensor utilizes the most current, practical technology to measure dissolved
oxygen. Currently, a luminescence quenching sensor (LDO) to measure dissolved
oxygen is planned for tailrace monitoring. This type of sensor is the latest technology
which drastically reduces the frequency of maintenance and calibration of the DO
electrode (contrasted to the traditional Clark Cell). The monitor also has a temperature
sensor. The sensor has a Modbus communication protocol for direct connection to the
SCADA wave radio (no additional programming is necessary).
Perforated Standpipe
This 6 -inch diameter, PVC pipe is attached to a stricture (concrete wall, bridge piling,
etc.) to provide a permanent housing for the sensor. This pipe, perforated on the lower
end allows for free exchange of water and protects the sensor and cables from physical
damage, vandalism, and lightening.
Tailwater Sensor Cables
Standard, off -the- shelf, cables are supplied by the sensor vendor. These cables allow
power to be supplied to the instrument as well as data transmittal to the SCADA wave
radio. Each cable end has a specified fitting for the designated mated end. These cables
were chosen (in lieu of custom fabrication of wiring components) to allow rapid
troubleshooting and replacement (if necessary).
Power Supply, 12 v
Supplies power to SCADA wave radio and sensors
SCADA Wave Radio
This is the standard Duke radio link to send and receive data. The SCADA radio transfers
data from remote sensors to the Fix32 system computer. Line of sight clearance is
required between radio links.
Station Computer
The tailrace water quality monitoring data is received by the current operating program at
all Catawba Hydros, the system receives sensor input (all plant sensors) and displays the
readings. The tailrace water quality monitoring data is integrated into plant operations
and is part of the display that the operators are accustomed. In addition, the station
computer serves as a backup database.
PI Database
This is the database currently used by Duke for storing all generation data from all
facilities. PI has the ability to record and store data at specified intervals. Standard
software extracts data from PI to be used in display formats for operators and /or
reporting.
The first criterion for the placement of the water quality monitors follows the requirements of the
Catawba - Wateree Comprehensive Relicensing Agreement. A schematic of the Catawba River
(Figure 4) illustrates the various developments, water release points, and required monitoring
locations.
10

Duke Energy Carolinas Catawba-Wateree Project No. 2232
Draft Quality Assurance Project Plan
Figure 4: Schematic Drawing of the Catawba River
Catawba
Linville River
COMPLIANCE MONITORING LEGEND
USGS gage (flow)
Duke gage (flow)
Reservoir Level
Water Quality (Temp & DO)
USGS type Staff gage Plate
LEGEND
— ------ 0 Powerhouse release
Recreation release
Continuous release
Regulated reach or
River tributary inflow
-- - * Bypassed reach
Lake Resrevoir
Dam Structure
11
Lake Hickory
Oxford Oxford
Powerhouse Dame
EM
I-F
I UM, !TIM
Lookout Shoals Lake
Lookout Lookout
Shoals Dam' Shoals PH
Lake Norman
Cowans I Cowans
Ford PH Ford Dame
Mountain Island Lake
Mountain Mountain
Island PH I Island Dam'
(Continued )
Catawba
U Linville
Arm of
Lake James Arm of
Lake
r]
Lake
Catawba
Paddy Ck
Paddy Ck
Bridgewater
Linville
Dam'
Dam
Spillway'
I Powerhouse
Dam
0 ;
-------- I
Paddy Creek
inville River
------------------------------
Catawba River Bypassed Reach
Muddy
y
Creek
Catawba tawba River
Lake Rhodhiss
Rhodhiss
Rhodhiss
Notes:
Dam'
I Powerhouse
1. Overflow spillway
2. Gated spillway
COMPLIANCE MONITORING LEGEND
USGS gage (flow)
Duke gage (flow)
Reservoir Level
Water Quality (Temp & DO)
USGS type Staff gage Plate
LEGEND
— ------ 0 Powerhouse release
Recreation release
Continuous release
Regulated reach or
River tributary inflow
-- - * Bypassed reach
Lake Resrevoir
Dam Structure
11
Lake Hickory
Oxford Oxford
Powerhouse Dame
EM
I-F
I UM, !TIM
Lookout Shoals Lake
Lookout Lookout
Shoals Dam' Shoals PH
Lake Norman
Cowans I Cowans
Ford PH Ford Dame
Mountain Island Lake
Mountain Mountain
Island PH I Island Dam'
(Continued )

Duke Energy Carolinas Catawba-Wateree Project No. 2232
Draft Quality Assurance Project Plan
ammm
I I ME
Notes:
1. Overflow spillway
2. Gated spillway
3. With flash boards
ME W
(Continued )
W
Mountain Island Lake
Mountain Mountain
Island PH I Island Dam'
7-- -1
Lake Wylie
Wylie Wylie
Dame I Powerhouse
1861 mm !TM1
1W
Fishing Creek Lake
Fishing I Fishing
Creek PH I Creek Dame
12
1W
Great Falls Reservoir
Great Falls
Great Falls
Dearborn
Great Falls
Great Fall
Powerhouse
Dam
Powerhouse
Headwork' '3
Diversion' '3
Rocky Short
Creek Bypass
Long
Bypass
Cedar Creek Reservoir
Rocky
Rocky Crk
Cedar
Creek PH
I Dam 1 , 2
Creek PH
12

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
The figures below show the proposed locations and discuss the rationale of the monitoring
equipment location at each of the Catawba - Wateree Developments. The specific locations are
based upon the criteria identified in Section A5.0 and downstream field testing.
Figure 5: Bridgewater Water Quality Monitoring Location
Map
Data
Recommended
Approximate
Comments
Data Collection
Location
Location
Distance
Downstream
(miles)
1
Bypassed Reach
Catawba Dam
0.00
Floe sensor at
Wireless Telemetry
Minimum
floe release valve
to Station Computer
Continuous
and Staff Gage for
Flows
Visual
13

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Map
Data
Recommended
Approximate
Comments
Data Collection
Location
Location
Distance
Downstream
(miles)
2
Minimum
Downstream of
0.65
USGS Gage
USGS Gage and
Continuous
1'r Bridge
(New Gage)
Turbine Generation
Floes
Powerhouse
Records
Recreational
Road
Flows
Project Hourly
Flows
3
Temperature
1'r Bridge
0.25
Irr Situ - Pipe and
Wireless Telemetty
Dissolved
Powerhouse
Instruments on
to Station Computer
Oxygen
Road
Bridge
Linville River
(NCDOT
Downstream
approval required)
Bridgewater
Hydro
4
Reservoir
Bridgewater
n/a
Current Device on
Wired to Station
Levels
Forebay
the Intake
Computer
Structure
Device Location Rationale
The valve at the Catawba Dam will be designed to supply seasonal minimum continuous flows
in the Catawba River Bypassed Reach (Location 1). A sensor in the flow pipe or valve,
calibrated for flow, will provide a continuous reading of the flow being released into the
Catawba River Bypassed Reach. Since the sensor is located directly on the valve or flow pipe,
which is on the dam, the sensor should be secure from vandals.
The channel configuration at the proposed site for the new USGS gage is ideally suited for the
expected range of flows originating from the Linville Dam. The site is located on private
property providing a measure of security.
The previous water quality monitoring site was located on the downstream side of the
powerhouse. Even though that site adequately represented the turbine flow water quality, the
future configuration of the Bridgewater Powerhouse is not known, and, therefore, the
recommendation for the future water quality monitoring location is at the first downstream
bridge (on Powerhouse Road). The bridge provides an existing stricture to place the water
quality monitor in the center of the narrow river channel. The temporary monitors placed at this
site during the Bridgewater downstream investigations (Knight 2003) illustrated similar water
quality values to the tailrace monitor at all flows except the 50 cfs leakage flows that will be
replaced by 75, 95 or 145 cfs minimum continuous flows in the future depending on the month.
This site will represent the water quality conditions of any combination of hydro unit flow
(including minimum flow). In addition, the site would be accessible under all Project flows, and
would provide a rapid response at the station to water quality conditions. Security from vandals
is a concern at this site.
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Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Figure 6: Rhodhiss Water Quality Monitoring Location
Map
Location
Data
Recommended
Location
Approximate
Distance
Downstream
(miles)
Comments
Data Collection
1
Temperature
Rhodhiss Road
0.35
I0;itu - Pipe in
Wireless
Dissolved
Bridge
Center of Charnel
Telemetry- to
Oxygen
Downstream
and Instruments
Station
Rhodhiss Hydro
Mounted on
Computer
Bridge (NCDOT
approval required)
2
Reseivoir
Rhodhiss
n/a
Current Device on
Wired to Station
Levels
Forebay
the Intake
Computer
Structure
Device Location Rationale
The previous water quality monitoring site was located on the south corner on the downstream
side of the powerhouse. That site adequately represented the water quality of the turbine flow
when all the units were identical, however, the turbine venting tests (Duke Power 2005a),
indicated that this location was not representative of the combined flows from units with
differing aeration capability. Therefore, the monitor should be moved to the center of the river
channel at the downstream bridge (Location 1). The bridge not only provides an existing
15

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
stricture to place the water quality monitor in the center of the channel, but this site represents
the water quality conditions of any combination of hydro unit flows (Duke Power, 2005a). This
site is accessible under all Project flows, and may provide a rapid response at the station to water
quality conditions. Security from vandals may be a slight concern at this site.
Figure 7: Oxford Water Quality Monitoring Location
16

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Map
Data
Recommended
Approximate
Comments
Data Collection
Location
Location
Distance
Downstream
(miles)
1
Temperature
Highway 16
0.15
Ii Situ -Pipe
Wireless
Dissolved
Bridge
South Charnel
Telemetn- to
Oxygen
Downstream
and Instruments
Station
Oxford Hydro
Mounted on
Computer
Bridge
(NCDOT
approval required)
2
Minimum
Oxford Dam
0.00
Flow sensor at
Wireless
Continuous
flow release valve
Telemetry- to
Flows
Station
Computer
3
Recreational
Riverbend Park
0.30
USGS -Type Plate
Staff Gage for
Flows
Turbine Records
Gage
Visual and
Project Hourly
Turbine
Flows
Generation
Records
4
Reseivoir
Oxford Forebai-
n/a
Current Device on
Wired to Station
Levels
the Intake
Computer
Structure
Device Location Rationale
An aerating flow valve will be designed to supply and measure a constant minimum continuous
flow in the downstream channel (Location 2). A sensor in the discharge pipe or valve, calibrated
for flow, will provide a continuous reading of the flow being released into the river channel.
Since the sensor is located directly on the valve or flow pipe, which is on the dam, the sensor
should be secure from vandals. The flow valve will provide the minimum continuous flow
during periods of no hydro unit generation.
Generation and recreational flow requirements will be recorded from the generation records for
each turbine. A manually read, USGS type plate staff gage will be placed at the boat put -in at
Riverbend Park (Location 3) for independent verification.
The previous water quality monitoring site was located in the corner of the powerhouse and
wingwall. That site adequately represented the water quality of the turbine flow when all the
units were identical and prior to the recent installation of the tailrace buttresses. However, this
site would probably not be representative of the combined flows from hydro units with differing
aeration capability and the buttresses would effectively prevent Unit 2 water from reaching the
sensor when Unit 1 was generating. Therefore, the monitor should be moved to the Highway 16
Bridge immediately downstream of the turbines (Location 1). The bridge not only provides an
existing stricture to place the water quality monitor in the channel, but this site will represent the
water quality conditions of any combination of hydro unit flows. This site will be accessible
under all Project flows, and will provide a rapid response of the station to water quality
conditions. Security from vandals may be a concern at this site.
17

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Figure 8: Lookout Shoals Water Quality Monitoring Location
Map
Data
Recommended
Approximate
Comments
Data Collection
Location
Location
Distance
Downstream
(miles)
1
Temperature
East Wingwall -
0.01
I0;itu - Pipe,
Wired to Station
Dissolved
Tailrace
Monitor Location
Computer
Oxygen
Unchanged
2
Minimum
Turbine Records
n/a
n/a
Turbine
Continuous
Generation
Flows
Records
Project Hourly
Flows
3
Reseivoir
Lookout
n/a
Current Device on
Wired to Station
Levels
Forebay
the Intake
Computer
Structure
Device Location Rationale
The minimum continuous flow will be provided by either one of the small auxiliary hydro units
(Location 2) during periods when the larger hydro units are not operating. The configuration of
the Lookout Shoals tailrace (large pool upstream of first downstream hydraulic control) exhibits
very little stage change with or without the auxiliary hydro unit generation. In addition, the
18

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
elevation of the tailrace is also a function of Lake Norman's reservoir level (at full pond, the
reservoir level extends upstream of the hydraulic control). Therefore, the minimum continuous
flow and hourly flow rates would be best monitored by the individual generation records of each
hydro unit at Lookout Shoals Hydro.
The previous water quality monitoring site was located on the east wingwall downstream of Unit
1. That site adequately represented the water quality of the turbine flow when all the hydro units
were identical. The nearest downstream stricture to place a monitor in the center of the channel
is the I -40 Bridge which is 13 miles downstream. The I -40 Bridge site is strongly influenced by
Lake Norman's reservoir level, and the long travel time of the minimum flow would influence
the water quality at minimum flow. Therefore, the I -40 Bridge location is not preferred for water
quality monitoring. Since no other downstream stricture exists to place a monitor in the center
of the river, the wingwall site (Location 1) represents the best logistical option available for
water quality monitoring. This wingwall site will be accessible under all Project flows, and will
provide a rapid response of the station to water quality conditions. The monitor will be secure
since it is located inside the security fence.
Figure 9: Cowans Ford Water Quality Monitoring Location
19

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Map
Location
Data
Recommended
Location
Approximate
Distance
Downstream
(miles)
Comments
Data Collection
1
Temperature
Railroad Bridge
0.50
Ir Situ -Pipe
Wireless
Dissolved
Downstream
West Charnel and
Telemetry- to
Oxygen
Cowans Ford
Instruments
Station
Hydro
Mounted on
Computer
Bridge
(Railroad
approval required)
2
Reseivoir
Cowans Ford
n/a
Current Device on
Wired to Station
Levels
Forebay
Intake Structure
Computer
Device Location Rationale
Even though the previous monitor was placed on the tail -deck of the hydro, this location
probably represented the water quality of the released flow. However, under multi -unit
operation, the monitor would only record data from the hydro unit flows adjacent to the monitor.
In addition, security at the Cowans Ford Hydro facility is controlled by the McGuire Nuclear site
(Nuclear Regulatory Commission guidelines) and is difficult to enter when operators are not
present. This security issue limits maintenance accessibility. Therefore, the recommended site
for the future temperature and dissolved oxygen monitoring is at the railroad bridge 0.5 miles
downstream (Location 1). This site would enable the monitor to measure water quality from the
high - volume hydro unit flow as well as provide a somewhat secure and accessible site. Location
of the monitor just west of the downstream tip of the island would insure that the monitor would
be out of the influence of the wastewater discharge from McGuire Nuclear Station.
20

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Figure 10: Mountain Island Water Quality Monitoring Location
Map
Data
Recommended
Approximate
Comments
Data Collection
Location
Location
Distance
Downstream
(miles)
1
Temperature
Tail Deck -
0.00
I0;itu - Pipe,
Wired to Station
Dissolved
Tailrace
Monitor Location
Computer
Oxygen
Unchanged
2
Reseivoir
Mt. Island
n/a
Current Device on
Wired to Station
Levels
Forebay
Intake Structure
Computer
Device Location Rationale
Even though the present monitor is on the tail -deck of the hydro (Location 1), this location
probably represents the water quality of the released flow. However, under multi -unit operation,
the monitor would only record data from the hydro unit flows adjacent to the monitor. Since no
other stricture, (e.g., bridge), exists in the center of Mountain Island's tailrace, this tail -deck
location represents the best logistical location available. It is secure and provides ready access
for maintenance.
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Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Figure 11: Wylie Water Quality Monitoring Location
Map
Location
Data
Recommended
Location
Approximate
Distance
Downstream
(miles)
Comments
Data Collection
1
Temperature
- 1/2 mile
0.50
Floe - Through
Wireless
Dissolved
Downstream
Svstem Auto
Telemetry- to
Oxygen
from Hydro
Calibration Sensor
Station
(pier on Ferrell
(Island property
Computer
Island)
owner's approval
required)
2
Minimum
Small Unit
0.00
USGS Gage
USGS Gage and
Continuous
Turbine Records
3.60
(Catawba River
Turbine
Flows
Highway 21
near Rock Hill,
Generation
USGS Gage
SC)
Records
(02146000)
22

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Map
Data
Recommended
Approximate
Comments
Data Collection
Location
Location
Distance
Downstream
(miles)
3
Recreational
Turbine Records
0.00
USGS Gage
USGS Gage and
Floes
Highway 21
3.60
(Catawba River
Turbine
Project Hourly
USGS Gage
near Rock Hill,
Generation
Flows
SC)
Records
(02146000)
4
Reseivoir
WOie Forebai-
n/a
Current Device on
Wired to Station
Levels
the Intake
Computer
Structure
Device Location Rationale
The USGS gage at the Highway 21 Bridge (Location 2/3) is well established and will be used for
verification of minimum continuous flow, recreational flows, and hourly Project flows. In
addition, generation records will be used to supplement the USGS data.
The previous water quality monitoring site was located in the corner of the powerhouse and
wingwall. Extensive monitoring of dissolved oxygen concentrations in the Wylie tailrace was
conducted during the 2002 turbine venting test (Duke 2005a). These results indicated that the
proposed monitoring location was the closest point to the hydro that best represented the water
quality of the multi -unit flows (Location 1). This test included detailed water quality sampling
along several downstream transects, as opposed to just at the monitoring site. Furthermore, the
Wylie tailrace is very complicated since the island immediately downstream of the powerhouse
splits the water released from the hydro. The flow, from either a single unit or multiple unit
operation, moves around the island and finally merges just upstream of the small island across
the channel from the proposed monitoring location. Use of this location is contingent on being
able to get permission for access from the property owner and on obtaining any necessary
easements. Security from vandals is of some concern at this site.
23

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Figure 12: Fishing Creek Water Quality Monitoring Location
Map
Location
Data
Recommended
Location
Approximate
Distance
Downstream
(miles)
Comments
Data Collection
1
Temperature
Highway 97/200
0.15
I0;itu - Pipe
Wireless
Dissolved
Bridge
West Charnel
Telemetn-
Oxygen
Downstream
and Instruments
to Station
Fishing Creek
mounted on
Computer
Hydro
Bridge
(SCDOT
approval
required)
2
Reseivoir
Fishing Creek
N/A
Existing Device
Wired
Levels
Forebai-
on the Intake
to Station
Structure
Computer
Device Location Rationale
The previous water quality monitoring site was located on the wingwall, west of the Fishing
Creek Powerhouse. That site adequately represented the water quality (temperature and
dissolved oxygen) of the turbine flow when all the hydro units were identical and prior to the
recent installation of the tailrace buttresses. However, this site would probably not be
representative of the combined flows from hydro units with differing aeration capability since
24

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
the flows will be directed downstream due to the newly installed buttresses. Therefore, the
monitor will be moved to the Highway 97/200 Bridge immediately downstream of the turbines
(Location 1). The bridge not only provides an existing stricture to place the water quality
monitor in the channel, but this site will represent the water quality conditions of any
combination of hydro unit flows. This site is accessible under all Project flows, and will provide
a rapid response of the station to water quality conditions. Security from vandals may be a
concern at this site.
Figure 13: Great Falls- Dearborn Water Quality Monitoring Location - Diversion Dam
25

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Figure 13 (cont'd): Great Falls- Dearborn Water Quality Monitoring Location -
Headworks
26

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Figure 13 (cont'd): Great Falls- Dearborn Water Quality Monitoring Location - Main Dam
Map
Location
Data
Recommended
Location
Approximate
Distance
Downstream
(miles)
Comments
Data Collection
1
Bypassed
Diversion Dam
0.25 mi. from
Pressure
Wireless
Reaches
Long Bypassed
Fishing Creek Dam
Sensor
Telemetry
Minimum
Reach
calibrated to
to Station
Continuous
Downstream
correspond to
Computer
Flows
Fishing Creek
minimum
and
Recreational
Hydro
continuous
Staff Gage for
Flows
floe- pond
visual
level. Pressure
Sensor
calibrated to
correspond to
recreational
flows and pond
level.
2
Bypassed
Headworks
1.95 mi. from
Gate Position
Wireless
Reaches
Short Bypassed
Fishing Creek Dam
Sensor
Telemetry
Minimum
Reach
calibrated to
to Station
Continuous
Downstream
gate opening
Computer
Flows
Fishing Creek
corresponding
and
27

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Map
Data
Recommended
Approximate
Comments
Data Collection
Location
Location
Distance
Downstream
(miles)
Recreational
Hydro
to minimum
Staff Gage for
Flows
continuous
visual
flow.
Pressure
Sensor
calibrated to
correspond to
recreational
flows and pond
level.
3
Temperature
Duke Bridge
0.1 mi. from Great
Ii Situ -Pipe,
Wired to Station
Dissolved
Downstream of
Falls — Dearborn
Monitor
Computer
Oxygen
Hydros
Dam
Location
Unchanged
4
Reseivoir
Great Falls
N/A
Existing
Wired
Levels
Forebai-
Device
to Station
on the Intake
Computer
Structure
Device Location Rationale
Ideally, measurement of the minimum continuous flows and recreational flows in the Great Falls
Long and Short Bypassed Reaches would be taken directly in the respective channels. However,
the irregular channel configuration in both reaches prevents accurate flow measurements from
stage changes. In addition, the difficult access to the bypassed reaches poses substantial
personnel safety limitations to the calibration and maintenance of the gages. Therefore, the best
measurement of the flow in the bypassed reaches is at the source of the flows (Locations 1 and
2).
Although the exact design of the minimum continuous flow delivery mechanism has not been
completed, the measurement of flow will be a stage- discharge relationship between the pond
level and the flow being delivered. Continuous flow monitoring for the Long Bypass will be
located at the Great Falls Diversion Dam immediately downstream of Fishing Creek Hydro
(Location 1). The continuous flow monitoring for the Short Bypassed Reach will be provided at
the Great Falls Headworks spillway, both upstream and downstream of the headworks stricture
(hence a flow measurement system upstream and downstream of the headworks) (Location 2).
Recreational flows will be provided as spill over the Great Falls Diversion Dam and the Great
Falls Headworks. Again, the water level over the spillways will be measured and stage -
discharge equations will relate stage to flow. Manually read, new USGS type plate staff gages
will be placed at the Great Falls Diversion Dam and upstream of the Great Falls Headworks.
28

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
The previous water quality monitor mounted on the Duke Energy bridge immediately
downstream of Great Falls and Dearborn Hydros is ideally located since it is in the center of the
channel (Location 3). This position captures the water quality (temperature and dissolved
oxygen) from both hydros and is in a secure location.
Figure 14: Cedar Creek Water Quality Monitoring Locations
Map
Data
Recommended
Approximate
Comments
Data Collection
Location
Location
Distance
Downstream
(miles)
1
Temperature
Downstream
0.00
I0;itu - Pipe,
Wired to Station
Dissolved
Face of Cedar
Monitor Location
Computer
Oxygen
Creek
Unchanged
Powerhouse
2
Reseivoir
Cedar Creek
n/a
Current Device on
Wired to Station
Levels
Forebay
the Intake
Computer
Structure
Device Location Rationale
The previous water quality monitor is located in the center of the Cedar Creek tailrace. It was
mounted directly on the powerhouse. Since the hydro units at Cedar Creek were identical, the
29

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
temperature and dissolved oxygen monitor adequately measured the water quality released from
Cedar Creels Powerhouse (Location 1).
The water quality of the Cedar Creels hydro flow represents the overall tailrace water quality
since:
• Cedar Creels Powerhouse flow is significantly greater than Rocky Creels Powerhouse
flow and dominates the downstream flow (capacity of Cedar Creek units is three times
the capacity of the Rocky Creek units).
• Rocky Creek Hydro is operated infrequently; it is operated only after Cedar Creek
Reservoir pond level cannot be maintained by Cedar Creek Hydro (three Units at Cedar
Creek).
• Both hydros draw water from the same forebay and the water quality is similar.
Thus, no water quality monitoring device is necessary at the Rocky Creek Hydro. Unlike Great
Falls- Dearborn, there is no stricture downstream of Cedar Creek Powerhouse to mount a water
quality monitor in the center of the channel.
30

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Figure 15: Wateree Water Quality Monitoring Locations
Map
Data
Recommended
Approximate
Comments
Data Collection
Location
Location
Distance
Downstream
(miles)
1
Temperature
West Platform —
0.02
Probably Floe-
Wired to Station
Dissolved
Tailrace
Through System
Computer
Oxygen
Auto Calibration
Sensor
2
Minimum
Highway 1/601
7.4
USGS Gage
USGS Gage and
Continuous
USGS Gage
( Wateree River
Turbine
Flows
near Camden, SC)
Generation
(02148000)
Records
31

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Map
Data
Recommended
Approximate
Comments
Data Collection
Location
Location
Distance
Downstream
(miles)
3
Recreational
Turbine Records
7.4
USGS Gage
USGS Gage and
Floes
Highway 1/601
(Wateree River
Turbine
Project Hourly
USGS Gage
near Camden, SC)
Generation
Flows
(02148000)
Records
4
Reseivoir
Wateree
n/a
Current Device on
Wired to Station
Levels
Forebay
the Intake
Computer
Structure
Device Location Rationale
The USGS gage at Highway 1 /601(Location 2/3) is well- established and will be used for
verification of minimum continuous flow, recreational flows, and hourly Project flows.
Generation records will be used to supplement the USGS data.
The Wateree tailrace is a relatively simple channel, with the flows from the various hydro units
moving directly downstream. However, the tailrace does not lend itself to simple water quality
monitoring due to the various aeration capabilities of the individual hydro units and subsequent
multi -unit flow patterns (Duke Power 2005a). Moving the monitor location downstream to
capture a multi -unit flow is not an option because, at flows greater than provided by 2 -3 unit
operations, a significant volume of water flows out of the main channel to the east within a few
hundred yards of the powerhouse.
The existing monitor location (Location 1) was built to extend a short distance into the tailrace
with the goal of better measurements than at the face of the powerhouse. The existing monitor
location is the best logistical location available to measure water quality because no stricture
exists in the center of the channel, nor is the east side of the channel a viable option because that
area is heavily used by fisherman (creating damage and security issues) and is prone to flooding
and further potential damage or loss.
The next available location at the Highway 1/601 Bridge is not suitable because of its distance
from the Powerhouse and the presence of aquatic plants and shoals between the Powerhouse and
bridge that significantly influence the DO levels.
B2.0 Sampling Methods
All dissolved oxygen and temperature data will be collected In ,Situ using submerged instruments
within standpipes attached to a permanent stricture in the tailrace. The instruments will be
powered by an external power source and data transmitted to the station operational computer.
The data are available in real -time for operational decisions regarding aeration.
The tailrace data will be collected between April 1 and November 30 each year, with an annual
report available June 30 of the following year. This monitoring period was selected based upon
the 10 -year monitoring presented in the License Application. At no time were dissolved oxygen
concentrations less than 5 mg /l during the period December through March.
32

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
B3.0 Sample Handling and Custody
No samples will be collected, transported, or stored since all dissolved oxygen and water
temperature measurements will be recorded in situ.
B4.0 Analytical Methods
The Winkler determination for dissolved oxygen is the only chemical analytical method
employed for the monitoring. This technique forms the basis of all instrument calibrations.
B5.0 Quality Control
Quality control measures for Dissolved Oxygen and Temperature measurements will include
proper calibration and regular tracking and servicing of instruments (see Sections B6 and 137).
Quality assurance activities include documentation of field procedures, data back -up, automatic
data logging, training, etc.
B6.0 Instrument/Equipment Testing, Inspection, and Maintenance
The Monitoring Field Manager is responsible for establishing the proper procedures for testing,
inspection, calibration, and maintenance of all water quality instruments. The procedures will
include a thorough evaluation of instrument performance; evaluations will include sensor
response times for large concentration differences and linearity checks of instrument calibration
from less than 10% DO saturation to greater than 100% saturation.
Quality control charts will be maintained for each instrument (tracked by serial number) for
response times and linearity over the lifetime of the instrument. In addition to obvious problems,
these charts will be used to evaluate the suitability of instrument deployment, instrument repair,
and /or return for manufacturer servicing.
All maintenance and servicing of instruments will be recorded by the field staff in a maintenance
log book and in an established electronic format.
B7.0 Instrument/Equipment Calibration and Frequency
Calibration of the Dissolved Oxygen Sensor(s) consists of either a primary calibration or a
secondary calibration.
Primary Dissolved Oxygen Calibration
This calibration consists of adjusting an instrument to read at the primary standard concentration
(manufacturer calibration method). This calibration is performed in the laboratory by adjusting
all instruments to a known concentration of oxygen, as determined by the Winkler method. Each
instrument, prior to deployment in a tailrace, shall be calibrated to the Winkler standard.
33

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Secondary Dissolved Oxygen Calibration
This calibration is reserved for evaluation of whether an instrument that has been deployed shall
remain deployed or taken back to the laboratory for maintenance. One designated instrument
(primary calibration performed that same day) shall be used at all sites that day to compare its
readings side -by -side with the deployed. If the differences between the two instruments are
greater than the manufacturers' tolerances, the deployed instrument shall be calibrated to the
recently calibrated instrument. If the deployed instrument does not calibrate or the differences
are greater than the control chart limits (see next paragraph), the deployed instrument shall be
returned to the laboratory for maintenance and be replaced with a recently calibrated (primary)
instrument.
Quality control charts shall be maintained for all comparisons of instruments. These charts shall
be maintained by individual instruments and by location. This data shall be used to determine
the limits of out of calibration tolerance for instrument field calibration criteria.
Initially, calibrations and checks on calibration will be conducted weekly. However, over time
the quality control charts will be used to adjust calibration frequency, especially if the
technologically advanced sensors require far less maintenance than conventional sensors.
B8.0 Inspection /Acceptance of Supplies and Consumables
The Monitoring Field Manager approves all orders for supplies required for instrument
maintenance and calibration. Upon receipt, all supplies will be inspected for damage. All
supplies and equipment ordered will be stored and documented in accordance with Duke's
Chemical Inventory and approved through Duke's chemical approval process.
B9.0 Non - Direct Measurements
Measurement data not obtained directly under the DO Monitoring Plan and this QAPP, including
hydro plant generating data, reservoir elevation data, National Weather Service weather data, and
U.S. Geological Survey (USGS) gage stream flow data, may be used for interpretation of
continuous DO monitoring data. Data collected by regulatory and governmental agencies will be
used and considered as valid data since these agencies have independent QA /QC programs to
ensure valid data. Catawba - Wateree Project generation data will be acquired through Duke
Energy's Hydro Fleet Operations.
Data from universities, non - governmental organizations, or industries may be used to analyze
continuous monitoring results depending upon methods, sampling design, and QA /QC
limitations. Citations will be made when such data are used.
B10.0 Data Management
The continuous DO and water temperature data are collected and monitored on a real time basis.
As the sensor detects the concentrations, the data is automatically transmitted to the PI data
system via the station computer. The PI database provides for permanent records storage while
the station computer temporarily stores the data should the transfer link to the PI system fail.
34

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Once in the PI data system, the data, or its derivatives, will be provided to Duke's real time
Hydro Operations Center.
The protocol for data transmission, storage, and retrieval is controlled by the Plant Information
(PI) database management team. Data files are stored for the duration of the project on the PI
data server, which is backed up electronically on a daily basis.
GROUP C — ASSESSMENT AND OVERSIGHT
CLO Assessment and Response Actions
The Monitoring Field Manager or a qualified QA /QC Auditor appointed by the Monitoring Field
Manager will perform an annual (after the field monitoring season) internal self - assessment of
the QA program to ensure the QA /QC records are complete and accountable. The self -
assessment results will be documented and provided to the Duke PM /QA Manager for the project
QA /QC files. Any corrective actions, as required, will be implemented and documented.
The Duke PM/QA Manager provides additional oversight through the review of the QA /QC
records generated for the continuous DO and water temperature monitoring. The Duke PM/QA
Manager will review and verify field data collection, data processing and data file submittals;
submittal of QA records to the QA /QC file; corrections or revisions to data files and any
subsequent documentation in the QA /QC file; and self - assessment results.
The Monitoring Field Manager will observe the field techniques of the Field Staff at periodic
intervals throughout the monitoring season. Any issues with technique will be corrected at that
time and documented in the appropriate field log book.
C2.0 Reports to Management
The process for reporting significant issues will follow a chain of command stricture. The
Monitoring Field Manager will report problems to the Duke PM/QA Manager and will address
the problem.
The Duke PM /QA Manager will receive annual reports, copies of log books, and calibration
forms for review and will ensure that these records are maintained in a designated QA /QC file.
GROUP D — DATA VALIDATION AND USABILITY
DI.0 Data Review, Verification, and Validation
Throughout the monitoring season, the Monitoring Field Staff or Monitoring Field Manager will
periodically transfer data from the PI system to software designed to perform provisional data
summaries and trend analysis. Calibration and maintenance data will be incorporated into this
program /database.
The Monitoring Field Manager will review this data for completeness and flag suspect data
and /or evaluate anomalies, trends, compliance issues, etc and will provide the provisional data,
35

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
along with recommendations, to the Duke PM /QA Manager after it is processed. Only the
Monitoring Field Manager has access to the database to change or correct data. The Monitoring
Filed Manager will provide the Duke PM /QA Manager with a copy of the final Annual Database
at the end of the field monitoring season. Supporting calibration forms and maintenance records
will be transferred to the Duke PM /QA Manager.
D2.0 Verification and Validation Methods
Throughout the entire monitoring season the database is archived systematically to ensure no
loss of data and to guarantee database integrity. At the end of the field monitoring season, all
forms, original data, and the database will be archived in electronic format on digital media; and
stored in an electronic storage format as well as by the Duke PM /QA Manager.
D3.0 Reconciliation with User Requirements
The real time data will be available in the Hydro Operating Center which will be displayed with
real -time trending analysis "process book" and PI related calculation tools. The real time
presentation allows for quick identification of instrument and or operational issues with the data
and allows for immediate problem identification and resolution.
Data collected during the Catawba - Wateree Compliance Monitoring program will be used to
adjust hydro operations to comply with the requirements of the 401 Water Quality Certification
and the FERC license and provide water quality data for reporting compliance, and /or non-
compliance events to appropriate agencies, as well as conducting on -going evaluations regarding
equipment performance and operational guidelines.
In the event that anomalies are found in the data, the Duke PM /QA Manager will review the field
notes taken by the Monitoring Field Manager and look for storm events or unusual watershed
conditions and assess their effects on data.
Data collected for each monitoring season will be put in report form and provided to NCDWQ,
SCDHEC, Duke and FERC, as well as archived in the PI system. Any anomalies and analysis
for any peaks or changes in data throughout the year will be documented in the reports provided
by the Field Manager to the Duke PM/QA Manager. Any sampling design modifications will be
considered only after consultation with NCDWQ /SCDHEC.
36

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
REFERENCES
Duke Energy. 2006. Catawba- Wateree Project FERC T 2232 Application for New
License Exhibit E Water Quantity, Quality, and Aquatic Resources, ,Stltdv Reports.
Duke Energy. Charlotte, NC.
United States Environmental Protection Agency. 2001. EPA Requirements for Quality Assurance
Project Plans. EPA QA /R -5, EPA /240/13- 01/003. USEPA, Office of Environmental
Information, Washington D.C.
Wagner, R. J., H. C. Mattraw, G. F. Ritz, and R. A. Smith. 2000. Guidelines and Standard
Procedures for Continuous Water - Quality Monitors: Site Selection, Field Operation,
Calibration, Record Computation, and Reporting. U. S. Geological Survey, Water -
Resources Investigations Report 00 =4252. Reston, Virginia.
37

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
APPENDIX A -QAPP
Standard Operating Procedures
For In Situ Compliance Monitoring
(To be completed upon receiving equipment and manufacturer's operating manuals)
1. Laboratory Evaluation of Water Quality Sensor Performance
(Make sure sensor performs as designed)
2. Configuration and Calibration of Water Quality Sensors Prior to Field Deployment
(Setup and calibration of instrument before deployed in tailrace)
3. Determination of Dissolved Oxygen Using the Winkler Method
(Used for laboratory calibration of sensors)
4. Routine Maintenance of Water Quality Sensor after Field Deployment
(Cleaning, troubleshooting, and storing instrument between field deployments)
5. In -field Instrument Performance Check, Calibration, and Criteria for Instrument Replacement
(Verification of instruments calibration while deployed and /or instrument replacement)
38

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
APPENDIX B -QAPP
Bridgewater Development
Supplemental Trout Habitat Monitoring
The Catawba River Bypassed Reach and Bridgewater minimum continuous flows have been
selected and evaluated to provide flows and water temperatures suitable for protection and
enhancement of mussels in the bypassed reach and the maintenance of a stocked trout fishery
downstream of Bridgewater Hydro. The volume of warm water flows provided to the Catawba
River Bypassed Reach to maintain mussel habitat are balanced against the coldwater minimum
flow from the Linville Dam to maintain suitable temperatures for trout downstream of the
confluence of the Catawba River Bypassed Reach and the Linville River. The flows and
temperatures provided to each channel to achieve the desired, but conflicting temperature
requirements were analyzed by the CE- QUAL -W2 reservoir model and the River Modeling
System (RMS). The results of these computer models were evaluated by the Aquatics /Terrestrial
and Water Quality Resource Committees. Bypassed Reach and Linville Dam minimum
continuous flows stated in the CRA are the result of the recommendations from the evaluations
by the resource committees.
Monitoring
Due to the hydraulic complexity and apparent conflicts of resource management interests
(differing trout and mussel temperature preference) in this area, supplemental monitoring will be
used to support future evaluations of whether trout management goals in the main stem Catawba
River continue to be supported. This supplemental trout habitat monitoring will commence after
the Bridgewater Powerhouse has been replaced with either a new powerhouse or valve system
and compliance operations have begun. This measurement and evaluation will continue through
the next cycle of NCDWQ Catawba River Basinwide Assessment period, but not beyond Year
2019. Results of this monitoring are not intended to be used for water quality certification
compliance purposes, but for continued aquatic resource assessments. These monitoring results
may be used to determine if flow reductions need to be made in the Catawba River Bypassed
Reach.
Sensor Locations
The temperature and level logger placement is designed to be able to record temperatures, flow
(level logger with stage- discharge relationship) from the inflows, and empirically determine the
temperatures at the appropriate downstream river reaches. An additional temperature and level
logger will be provided at the Watermill Bridge (RM 271.7) in Glen Alpine, NC which is in the
middle of the primary trout habitat.
39

Duke Energy Carolinas Catawba - Wateree Project No. 2232
Draft Quality Assurance Project Plan
Bridgewater Supplemental Trout Habitat Monitoring
System Requirements
Level loggers (devices to record river stage from which a stage- discharge relationship may be
developed to calculate flow) and temperature loggers will be placed in the river and periodically
downloaded to obtain the respective data. Stage- discharge curves will be developed at the level
logger sites.
Reporting Requirements
Annual reports will be provided to NCDWQ and NCWRC (30 April) for the duration of the
supplemental trout habitat monitoring detailing the previous calendar year's temperatures and
levels. Flow- weighted temperatures will be calculated for the downstream sites.
40

APPENDIX B
APPLICATION OF THE DISCRETE BUBBLE MODEL TO TURBINE
AERATION ASSESSMENTS FOR THE CATAWBA - WATEREE PROJECT

Application of the Discrete Bubble Model to Turbine Aeration
Assessments for the Catawba - Wateree Project
Daniel F. McGinnis, Surface Waters - Research and Management, Swiss Federal Institute of
Aquatic Science and Technology, Eawag, CH -6047 Kastanienbaum, Switzerland
dan.mcuinnis E,eawa ,y.ch
Richard J. Ruane, Reservoir Environmental Management, Inc, 900 -5 Vine Street, Chattanooga,
TN 37403 jimruane comcast.net

Introduction
Turbine venting has commonly been used to increase low dissolved oxygen (DO) in the
releases from hydropower projects. It is estimated that some form of turbine venting is used or
being planned at over 70 hydropower projects. It often is the preferred aeration method
wherever it is applicable because other alternatives usually cost more, and project owners can
more readily operate and maintain turbine venting systems.
Turbine venting systems were first used in the 1940s on the Fox River in Wisconsin, and
this approach continues to be studied and advanced (Sheppard and Miller, 1982; Carter, 1995;
Harshbarger, 1999; Thompson and Gulliver, 1997; Hopping et al., 1997 and 1999) to increase
their effectiveness and address current issues.
Turbine aeration modeling has been used at selected projects to better understand and
predict the performance of turbine venting systems (Raney, 1973; Sheppard et al, 1981; Quigley
and Boyle, 1976; Wilhelms et al, 1987). These previous models were based on first -order gas
transfer equations that accounted for mass transfer and the ratio of air flow to water flow.
Thompson and Gulliver (1997) developed an approach that incorporates turbine system
similitude considerations and tested it on one project.
In recent years the discrete bubble model (DBM) that accounts for bubble size in addition
to the variables accounted for in the above models had been applied successfully to several lake
aeration systems, so the authors applied it to turbine venting systems. The DBM has been
verified with diffused - bubble oxygen transfer tests conducted in a tank, 14 meters deep, at three
air flow rates. All of the test data were predicted to within 15% (McGinnis and Little, 2002).
The range of bubble diameters during the test (0.2 to 2 mm) spanned the region of greatest
variation in rise velocity and mass- transfer coefficient. This approach has subsequently been
successfully applied to airlift aerators (Burris and Little, 1998; Burris et al., 2002), the Speece
Cone (McGinnis and Little, 1998), linear and circular bubble -plume diffuser (Wiiest et al., 1992;
Little and McGinnis, 2001; McGinnis et al., 2001) and sidestream supersaturation systems
(Mobley, 2001).
The first DBM applications to turbine aeration systems were for the Saluda Project near
Columbia, SC. These applications included predicting DO in the turbine releases considering
various turbine venting alternatives (2003), setting up and running the models to predict hourly
concentrations of DO in an operational mode over representative hydrologic years (2003), and
developing lookup tables for operators to use for aerating the releases from the project using the
current turbine venting systems (2004- 2007). The operational runs using various aeration

alternatives were used to assist in developing a site - specific water quality standard for DO in the
Lower Saluda River downstream from the Saluda Project.
The DBM was selected for use on the Catawba - Wateree Project because it is believed that
it has several advantages over previous turbine venting models for predicting aeration beyond the
range of conditions for which data are available and the models are calibrated. DBM includes a
more mechanistic description of the factors affecting gas transfer as described below; therefore,
it should provide a better prediction of oxygen transfer for conditions lacking data (i.e., DO
uptake at higher airflows; Lookout Shoals, Mountain Island; at lower water flows and new
aerating wheels for the small units at Wylie and Wateree; and for new draft tubes at Linville).
The DBM also offers the capability to test sensitivity of mass- transfer and initial bubble size to
predicted conditions.
Background
Gas Exchange Theory and the Discrete - Bubble Model
The discrete bubble model, the foundation of the turbine aeration model, predicts gas
transfer (both dissolution and stripping) across the surface of individual bubbles and
simultaneously tracks both gaseous (bubble) and dissolved nitrogen and oxygen, but can easily
include more gases (e.g., methane). The basic model equation has been described by many
researchers [Leifer and Patro, 2002; McGinnis and Little, 2002; Vasconcelos et al., 2002; Wiiest
et al., 1992; Zheng and Yapa, 2002], with main differences being the parameterizations selected
for the mass transfer coefficients, rise velocities, diffusivities and gas solubility.
The amount of gas transferred is a function of several factors, with the most important
being gas partial pressure (defined here as the hydrostatic pressure X mole fraction of gas), initial
bubble size, and bubble -water contact time. The rate of change of the amount of gas in the
bubble relative to depth and gas species is given as:
where,
dFcn _ P 4�c1 °2
�� ��LF��F 7 � �T7�V +V (1)
b
FG = gas flux,
KL = mass transfer coefficient,
H = gas solubility constant,
P = pressure,

C = dissolved gas concentration,
r = bubble radius,
v = velocity,
z = depth,
v = bubble
= gas species, oxygen or nitrogen
Note that in Equation 1, KL, and vb are bubble size - dependent (Table 1). The term v is vertical
component of water velocity in the turbine draft tube (vv is positive in upward flowing water,
negative in downward flowing water). The model was written in FORTRAN, and numerically
integrated using the Euler method [McGinnis et al., 2006].
Table 1. Correlation equations for Henry's Law constant, mass transfer coefficient, and
bubble rise velocity (Wiiest et al., 1992)
Equation Range
Ko = 2.125 x I V - 5.021 x 10 -7T + 5.77 x 10_9T 2 (mol M-3 Pa-1) (T in Celsius)
KN = 1.042 x 10 -' - 2.450 x 10 -7T + 3.171 x 10-9 T 2 (mol M-3 Pa-1)
KoL = 0.6r (m s -1)
KoL = 4 x 10 -4 (m s -i)
r < 6.67 x 10 -4 in
r >_ 6.67 x 10 -4 in
vt, = 4474r1.357 (m s -1) r< 7 x 10 -4 in
vt, =0.23 (ms -1) 7 x 10 -4 <_r
<5.1x103m
vt, = 4.202r°.547 (m s -1) r >_ 5.1 x 10 -3 in
Size- Dependent Bubble Properties
Many parameterizations exist for rise velocity and mass transfer (See Leifer and Patro,
2002, for a thorough review of bubble experiments and theory); however, those selected for this
model were done so based on their simplicity and reported accuracy. The present model uses
rather simple correlation equations to determine terminal rise velocities of bubbles (Table 1)
[McGinnis and Little, 2002; Wiiest et al., 1992].

111101
N
E
U
10
U
O
N
a�
T
of
1 10 100
Bubble Diameter (mm)
Figure 1. Measured rise velocities of bubbles with different sizes. A simple correlation
was obtained for rise velocity as listed in Table 1 [after Wiiest et al., 1992].
Data shown are from Haberman and Morton [1954].
Like bubble rise velocity, the rate of gas transfer across the bubble surface is also affected
by many factors, including bubble size (surface area to volume ratio), internal gas circulation,
rise velocity, and surfactants [Alves et al., 2005; Clift et al., 1978; Leifer and Patro, 2002;
Vasconcelos et al., 2002; Vasconcelos et al., 2003]. The mass transfer coefficients for nitrogen
and oxygen are equal and are the same equations used by Wiiest et al. [1992] and McGinnis and
Little [2002] (Figure 2). The simple approach of assuming correlation equations from the data in
Figure 2 has been found to be appropriate for most shallow environments.
K82
0.05
N
E
0.04
Y
a� 0.03
U)
c
m
0.02
U)
0.01
0.00
0
O
o Tap water
Correlation
1 10 100
Bubble Diameter (mm)
Figure 1. Measured rise velocities of bubbles with different sizes. A simple correlation
was obtained for rise velocity as listed in Table 1 [after Wiiest et al., 1992].
Data shown are from Haberman and Morton [1954].
Like bubble rise velocity, the rate of gas transfer across the bubble surface is also affected
by many factors, including bubble size (surface area to volume ratio), internal gas circulation,
rise velocity, and surfactants [Alves et al., 2005; Clift et al., 1978; Leifer and Patro, 2002;
Vasconcelos et al., 2002; Vasconcelos et al., 2003]. The mass transfer coefficients for nitrogen
and oxygen are equal and are the same equations used by Wiiest et al. [1992] and McGinnis and
Little [2002] (Figure 2). The simple approach of assuming correlation equations from the data in
Figure 2 has been found to be appropriate for most shallow environments.
K82
0.05
N
E
0.04
Y
a� 0.03
U)
c
m
0.02
U)
0.01
0.00
0
1 2 3 4 5
Bubble Diameter (mm)
Figure 2. Mass transfer data for oxygen and nitrogen [Motarjemi and Jameson, 1978].
Solid line is correlation used by Wiiest et al. [1992].
Single Bubble Model Validation: Lab experiments
The bubble model was first validated using data collected in a laboratory setting, with
shallow controlled conditions. McGinnis and Little [2002] bubbled air through water in a 14 -m
high by 2 -m diameter tank with a porous hose diffuser and monitored the evolving oxygen
TV
0
O
AO
o Motarjemi and Jameson (1978)
- Wiiest et al. (1992)
1 2 3 4 5
Bubble Diameter (mm)
Figure 2. Mass transfer data for oxygen and nitrogen [Motarjemi and Jameson, 1978].
Solid line is correlation used by Wiiest et al. [1992].
Single Bubble Model Validation: Lab experiments
The bubble model was first validated using data collected in a laboratory setting, with
shallow controlled conditions. McGinnis and Little [2002] bubbled air through water in a 14 -m
high by 2 -m diameter tank with a porous hose diffuser and monitored the evolving oxygen

concentration. They first removed DO from the water by adding sodium sulfite. By doing this,
they significantly increased the salinity of the water. Three different tests were performed with
air at flow rates of 0.43, 0.68, and 2.88 Nm3 /hr, (1 Nm3 denotes 1 m3 of gas at 1 bar and 0 °C;
Figure 3). No parameters were adjusted in the model to obtain the fit, demonstrating the models
applicability to shallow fresh water.
Model Application: Incorporation of Dissolved and Gaseous Fluxes
The discrete - bubble model provides fundamental principles that can be used for various
aeration models. The basic bubble model has been expanded and applied to many aeration
technologies with great success. These applications include the downward flow bubble contactor
(i.e., Speece Cone) [McGinnis and Little, 1998], full -lift aerators [Burris and Little, 1998; Burris
et al., 2002], bubble -plume diffusers [McGinnis et al., 2004; Wiiest et al., 1992], side - stream
super saturation systems for rivers (Mobley Engineering, Inc., personal communications, 2001),
and turbine aeration units (this work).
14
12
10
J
E 8
0
6
4
2
2.88 Nm3
0.68
Nm3
0.43
Nm3
0
0 1 2 3 4 5 6 7 8 9 10
Time (hours)
Figure 3. Data vs. the model prediction of DO transfer from bubbles into water. Data
(symbols) are from McGinnis and Little [2002]. Model predictions account for
inclusion of salinity in the calculation of the DO and Dissolved Nitrogen (DN)
saturation concentrations.
Two basic equations common to all of the above - listed models are used to describe the
gas and water fluxes as the bubbles travel through a pipe in two -phase flow.

Dissolved Gas Flux
(DO and DN)
dF,:, _ 4Tcr`N
dz (v + vb 1— �g
Gas Flux
(DO and DN)
dFG _ 47rr ` N
- K L (H P -Cl)
dz v + vb
FD, and FG; are the fluxes (mol /s) of the modeled dissolved and gaseous species (denoted
by i). For example, modeling oxygen and nitrogen would result in a set of four simultaneous
differential equations. N is the number of bubbles per second in the system, and F-, is the
volumetric gas holdup, or void ratio, and is the volume of gas occupying a volume of water.
This set of equations is then numerically integrated along the pipe (distance z), based on the
following set of assumptions:
1. The bubbles are produced at a constant rate, and remain uniformly distributed across the
pipe.
2. Both water and bubbles are in plug flow, with negligible dispersion.
3. No bubble coalescence occurs, that is, N, the number of bubbles per second, remains
constant.
4. For a given set of boundary conditions, the bubbles produced are uniform in size.
5. Temperature is assumed constant throughout the pipe.
Application for Turbine Aeration
With the use of any models it should be recognized that modeling results provide a
general indicator of what is likely to occur under given sets of conditions. As is the case in all
aquatic environments, actual conditions are more complex than models, so models reproduce the
major patterns that are observed in the field, and usually lack resolution, inputs, or formulations
to reproduce all the minor patterns. Models are internally consistent and based on rigorous
governing equations, so they can often help explain apparent discrepancies in field observations.
Based on the previously listed applications, it is obvious that the discrete bubble -model
(DBM) approach is naturally suited to turbine aeration. This approach was first used by REMI
in 2003 on the Saluda project with excellent results, and has since been applied to various other
hydropower projects. See Figure 4 for schematic of bubble model application to turbine
aeration.
One of the basic equations that determines bubble contact time and bubble location in the
draft tube is

az
— =v +vb
dt
where z in this case is the centerline distance in the draft tube. It is important to note that the
sign of the bubble rise velocity, vv changes depending on the location in the draft tube and the
direction of flow. In the case of vertical, downward flow, the sign of vv is negative (the sign of
the water velocity, v, is always positive), resulting in longer contact time as the bubble is "rising"
in downward moving water. Where the draft tube is horizontal, vv is set to zero. It was assumed
that the bubbles are still dispersed in the water at this point. However, at lower water flow rates
coalescence was mimicked by using a larger bubble size at lower flow velocities, which
effectively reduced the surface area to volume ratio, simulating the effect of bubble coalescence.
It should be noted also that bubble size should increase with decreasing draft tube velocity due to
the lessening shear - effects on bubble size formation. For vertical, upward water flow, the sign of
vv is positive, resulting in shorter contact time as the bubble is now "rising" in the same direction
as the moving water.
Figure 4. Schematic of bubble model application to turbine aeration
/M
Aeration in the tailwater is calculated by assuming the bubbles rise vertically, with some induced
vertical water velocity. Preliminary jet -plume modeling and experience has shown that this
assumed vertical water velocity is generally about 50 percent of the velocity at the exit of the
draft tube.
General Calibration Procedure

The model has been applied to several hydropower projects with excellent success. The
calibration procedure and details are listed in the next section using Saluda and Wylie as
examples. However, generally, the process is as follows:
1. The geometry of the draft tube is developed and incorporated into the DBM program.
2. Using measured inflow and outflow DOs, measured airflow, temperature, turbine
flow, and tailwater elevation, the model is iteratively run to determine the bubble size
that most closely yields the measured DO. The initial bubble size vs. initial unit
water velocity is then plotted (Figure 5). The resulting data have been found usually
to fit a good trend, such as the power relation determined for Wylie and Saluda.
3. The model is run using the bubble size versus velocity relationship, and model
prediction errors are determined by comparing predictions with data.
E 4.0
V)
3.0
ID
2.0
d]
1.0
0.0
0
o Rhodhiss 1
❑ Rhodhiss 2
0 o Saluda
X X Wylie
° 6 Osage
—Poly. [Saluda]
❑ O Poly. [Wylie]
o X.
°m X X X X X
0.00 2.00 4.00 6.00 8.00 10.00
Velocity (m/s)
Table 2 lists the input data and model predictions for Saluda and Wylie. The tailrace DO
includes the influent DO, DO added in the draft tube by air bubbles, and the DO addition in the
tailrace due to additional oxygen transfer from bubbles, as well as any surface reaeration and
entrainment by the discharge plume. As the first iteration of the calibration, the initial bubble
size vs. draft tube velocity is estimated by fitting the model to the measured tailrace JR) DO
using the influent DO listed in Table 2.

NIodel Input Boundary Conditions
Nleasurements
NIodel Output Predictions
Rmr No.
UVE
I Discharge
Velocity
Air Floe
Temperature
DO in
DO
TD(
Entraimnent
Factor, E
DO
OTE
Bubble
Radius
I TDG
14.0
Feet
I cfs
I ft
I fs
°C
I mgL
mg :L
24
-
mg :L
1
nun
2123
16
176.0
637
5.1
89
17.1
0.16
650
107
050
6.5
15
42
108
17
175.8
928
7.4
97
17.0
0.16
623
107
050
6.2
20
2 3
107
18
175.6
1322
10.6
96
17 2
0.16
5.70
105
1 050
5.7
26
13
105
19
175.4
1515
12.1
88
17 2
0.16
5.40
104
050
5.4
31
0.9
104
20
175.4
1761
14.1
88
17 2
0.16
4.75
102
050
4.8
32
0.8
101
21
1753
2090
16.7
91
17.4
0.16
4.40
101
0.40
4.4
34
0.7
98
133
175.6
2200
17.6
91
17.4
0.16
4.13
99
0.40
4.1
33
0.7
98
23
175.8
2300
18.4
92
17.4
0.16
4.02
97
037
4.0
23
0.7
97
24
175.8
2450
19.6
94
17.4
0.16
3.91
97
031
3.9
34
0.7
97
25
175.9
2600
20.8
97
17.4
0.16
3.95
97
024
4.0
37
0.7
97
26
1759
2719
21.7
100
17.4
0.16
3.94
97
020
4.0
36
OJ
98
27
176.0
3004
24.0
80
17.4
0.16
3.60
96
0.08
3.7
46
0.7
96
28
176.1
3149
252
77
17.4
0.16
3.64
96
0.05
3.7
50
0.7
96
1
494.6
1565
115
62
275
3.70
559
113
050
5.6
17
2 6
113
1
494.8
1907
14.0
55
27.7
3.40
533
110
050
53
24
15
110
1
494.7
2123
15.6
53
27.8
3.60
536
110
050
5.4
26
12
110
1
4949
2275
16.7
48
27.9
330
4.98
107
050
5.0
29
1.1
107
1
495.0
2713
19.9
50
28.0
3.50
4.95
105
050
49
27
1.0
104
1
4952
2914
21.4
50
28.1
3.70
4.87
102
050
49
25
1.0
103
1
4953
3092
22.7
50
28.1
3.60
472
101
050
4.7
25
1.0
101
3
4942
1455
10.7
106
275
3.00
5.95
120
050
6.1
15
3 2
120
3
4945
1809
133
99
277
2.70
5.89
120
050
6.0
21
1.8
120
3
494.6
2160
159
90
27.8
2.70
5.76
119
050
5.8
26
12
119
3
495.1
2544
18.7
100
28.0
230
5.44
114
050
5.4
28
10
115
3
4952
2724
20.0
108
28.0
2.70
5.61
116
050
5.6
26
1.0
115
3
4955
2976
21.9
143
28.1
2 40
5.72
114
050
5.7
24
1 0
114
3
1 4955
3163
232
143
28.1
2.70
5.63
113
050
5.6
3
LO
113
3
495.6
3298
242
133
282
250
5.18
107
050
5 2
24
LO
107
3
1 495.7
3489
25.6
94
283
3.80
536
109
050
1 55
1 2 2
1 0.9
109
Table 2. Input data and model results for Saluda Unit 1 (top panel) and Wylie Units 1
and 3 (bottom panel).
To estimate the bubble aeration in the tailrace, the circle bubble plume model [McGinnis et al.,
2004; Wiiest et al., 1992] was used for several cases using the discharge velocity and bubble
conditions, with 50 percent of the exit velocity generally found to be a good approximation for
the discharge plume in the tailrace. This 50 percent has been found to be a good approximation
for other projects.
For both projects, the model reproduced the measured tailwater DO remarkably well
(Table 2 and Figure 6). The effect of the TWE is incorporated into the model.
7
6.5
6
O
5.5
LD
5
a 4.5
4
o
O
i o
• Bubble Model
o VENT model
4 4.5 5 5.5 6 6.5 7
Measured DO
7
E6
O
5
U
a 4
a` �
3 '
3
i
i
o
• Bubble Model _
o o VENT model
°o
4 5 6 7
Measured DO
Figure 6. Predicted vs. measured values for using the DBM and the USACE model. Left

panel: Wylie; right panel: Saluda
DO Predictions for Other Facilities of the Catawba - Wateree Project
In 2006, turbine venting studies were conducted on representative units at Rhodhiss,
Oxford, Lookout Shoals, Fishing Creels, Dearborn, Cedar Creels, and Wateree. Turbine venting
studies conducted in 2002 were used to calibrate the model for Wylie. The DBM model was
calibrated to the data collected on each unit studied at each facility, and the results are presented
in Table 3 and Figure 7.
7.0
0 RD1 Measured
��
-RD1 Predicted
G?
RD2Measured
-RD2 Predicted
6.0
i DB2 Measured
0
(]
®0B2 Predicted
0 FC1 Measured
5.0Q
-FC1 Predicted
Ll
4 FC2 Measured
�
FC2 Predicted
4 FC3 Measured
4.0
FC3 Predicted
E
A CC1 Measured
O
CC1 Predicted
p 3.0
c3 CC2Measured
0'"
CC2Predicted
0 WA2 Measured
2.0
0711
WA2 Predicted
0 WA3 Measured
WA3 Predicted
® L02 Measured
1.0
-L02 Predicted
o OX1 Measured
OX1 Predicted
0.0
o WY1 Measured
WY1 Predicted
1000
1500
2000
2500
3000
3500
A U11Y3 Measured
Flow (cfs)
WY3Predicted
Figure 7. Measured and predicted DO values for each turbine unit studied on the
Catawba - Wateree system

Run
O
Airflow
DOin
Temper-
ature
TWE
Measured
DO out
Predicted
DO
Bubble
Radius
Gas
Holdup
Initial
Velocity
Horizontal Avg
Velocity
cfs
cfs
mg /L
°c
ft -msl
mg /L
mg /L
mm
%
ft /s
ft /s
RD
4
1,565
68.3
4.9
25.2
932.0
6.3
6.3
3.8
4.6
7.6
2.8
6
1,505
69.9
5.2
25.1
932.0
6.3
6.3
5.5
4.9
7.3
2.7
8
1,743
62.5
4.8
25.0
932.0
6.5
6.5
2.3
3.8
8.5
3.2
10
1,931
58.4
4.9
25.0
932.0
6.1
6.2
2.5
3.2
9.4
3.5
RD2
4
1,773
74.7
4.1
24.4
932.0
6.1
6.1
2.5
4.5
8.6
3.2
6
1,872
79.4
4.3
24.4
932.0
5.8
5.8
3.3
4.4
9.1
3.4
8
2,336
78.5
4.2
24.4
932.0
5.8
5.8
2.0
3.5
11.4
4.2
10
2,511
77.7
4.3
24.4
932.0
5.7
5.7
1.9
3.3
12.2
4.6
FC U1
4
1,710
22.3
4.6
27.3
356.0
5.4
5.3
2.3
1.8
16.8
3.1
6
1,885
21.8
4.7
27.4
356.0
5.3
5.3
2.0
1.7
18.5
3.4
8
2,236
31.5
4.6
27.5
356.0
5.3
5.3
2.0
1 2.1
21.9
4.0
10
2,318
25.9
4.6
27.5
356.0
5.5
5.5
1.2
1.6
22.7
4.1
FC U2
4
1407
84.3
4.1
27.9
356.0
6.3
6.3
4.0
8.6
13.8
2.5
6
1626
86.0
4.7
27.9
356.0
6.2
6.2
4.5
7.6
15.9
2.9
8
1792
88.2
4.7
27.9
356.0
6.1
6.1
4.0
7.1
17.6
3.2
10
2184
89.1
4.8
27.7
356.0
6.1
6.1
3.0
5.9
21.4
3.9
FC U3
4
1404
78.2
4.8
27.6
356.0
6.6
6.6
4.0
8.0
13.8
2.5
6
1435
76.5
5.3
27.6
356.0
6.6
6.6
5.5
7.6
14.1
2.6
8
1701
83.5
5.5
27.6
356.0
6.6
6.6
5.0
7.1
16.7
3.0
10
1952
82.9
5.2
27.6
356.0
6.6
6.6
3.0
6.1
19.1
3.5
DB U2
4
1,948
81.3
4.9
28.7
283.0
6.6
6.6
4.0
4.6
9.5
3.3
6
2,177
87.7
4.9
28.7
283.0
6.3
6.6
3.5
4.5
10.6
3.7
8
2,530
84.3
4.6
28.7
283.0
6.0
6.0
3.5
3.7
12.3
4.3
10
2,708
78.0
4.6
28.7
283.0
5.7
5.7
3.9
3.2
13.2
4.6
LO U2
4
1103
9.4
4.3
26.5
765.0
4.8
4.8
2.5
1.1
16.5
2.1
6
1224
9.6
4.6
26.5
765.0
4.8
4.9
4.5
1.1
18.3
2.4
8
1444
9.3
4.5
26.5
765.0
4.7
4.7
5.0
0.8
21.6
2.8
10
1698
5.6
4.5
26.5
765.0
4.6
4.6
5.0
0.5
25.3
3.3
OX U1
4
1756
96.9
2.6
26.4
843.1
5.6
5.6
0.8
5.5
14.3
4.5
6
1919
91.9
3.1
26.4
843.2
1 5.1
5.1
1.0
4.8
15.6
5.0
8
2631
78.2
2.2
26.3
843.4
4.3
4.3
0.4
3.0
21.4
6.8
10
3014
0.0
2.2
26.3
843.6
2.6
2.6
0.4
0.0
24.6
7.8
WY U1
3
1565
61.8
3.7
27.5
494.6
5.6
5.6
2.6
3.9
11.0
3.6
6
1907
55.2
3.4
27.7
494.8
5.3
5.3
1.5
2.9
13.4
4.3
7
2123
53.2
3.6
27.8
494.7
5.4
5.4
1.2
2.5
14.9
4.8
10
2275
48.1
3.3
27.9
494.9
5.0
5.0
1.1
2.1
16.0
5.2
11
2713
49.8
3.5
28.0
495.0
4.9
4.9
1
1.8
19.1
6.2
14
2914
50.3
3.7
28.1
495.2
4.9
4.9
1
1 1.7
20.5
6.6
15
3092
50.1
3.6
28.1
495.3
4.7
4.7
1
1.6
21.7
7.0
WY U3
55
1455
105.9
3.0
27.5
494.2
6.0
6.1
3.2
7.3
10.2
3.3
58
1809
99.0
2.7
27.7
494.5
5.9
6.0
1.8
5.5
12.7
4.1
59
2160
89.8
2.7
27.8
494.6
5.8
5.8
1.2
4.2
15.2
4.9
62
2544
100.0
2.3
28.0
495.1
5.4
5.4
1
3.9
17.9
5.8
63
2725
108.1
2.7
28.0
495.2
5.6
5.6
1
4.0
19.2
1 6.2
66
2976
142.9
2.4
28.1
495.5
5.7
5.7
1
4.8
20.9
6.8
67
3163
142.8
2.7
28.1
495.5
5.6
5.6
1
4.5
22.2
7.2
70
3298
132.8
2.5
28.2
495.6
5.2
5.2
1
4.0
23.2
7.5
71
3489
94.2
3.8
28.3
495.7
5.4
5.5
0.9
2.7
24.5
7.9
WA U2
4
2024
33.6
1.9
28.2
143.5
2.9
2.9
1.4
3.0
15.3
5.8
6
2021
39.9
1.9
28.2
143.5
3.3
3.3
1.2
3.5
15.3
5.8
8
2145
38.9
1.9
28.4
143.5
2.8
2.8
1.7
3.2
16.3
6.2
10
2573
37.2
1.9
28.4
143.5
2.5
2.5
1.7
2.6
19.5
7.4
11
3021
19.3
1.9
28.5
143.5
2.1
2.1
2.0
1.1
22.9
8.7
WA U3
4
2030
170.8
2.9
28.0
143.5
7.0
6.9
0.5
8.4
15.4
5.9
6
2065
209.8
2.9
28.1
143.5
6.8
6.8
1.1
10.2
15.7
6.0
8
2396
247.0
2.9
28.2
143.5
6.5
6.5
1.2
10.3
18.2
6.9
10
2920
232.8
2.9
28.2
143.5
6.6
6.2
0.5
8.0
22.1
8.4
CC U1
4
2744
19.8
3.5
29.6
222.0
4.1
4.2
0.7
0.8
20.2
7.8
6
3108
19.4
3.8
29.6
222.0
4.5
4.3
0.7
0.7
22.8
8.8
8
3369
0.2
4.2
29.7
222.0
3.9
9.5
CC U2
4
2433
58.3
3.7
29.5
222.0
5.7
5.7
0.7
2.6
17.9
6.9
6
2548
50.5
4.3
29.5
222.0
5.8
5.8
0.7
2.1
18.7
7.2
8
2825
51.3
4.3
29.8
222.0
5.0
5.0
1.8
2.0
20.7
8.0
10
1 3429
1 23.7
1 4.3
30.1
222.0
4.9
4.8
0.7
0.8
25.2
9.7
Table 3. Summary of data collected and other model inputs determined to develop DBM
predictions. The first four projects are grouped together because they have lower horizontal
velocities.
As can be seen in Figure 7 and Table 3, the model was calibrated so that it matched the
DO data in the tailrace (i.e., DOout). This calibration approach was used so that the model
would essentially match the data for the field conditions under which the data were collected.

When the models were used for model nuns, the bubble radius values for intermediate unit flow
levels were interpolated between those flow levels tested. This approach is deemed most
appropriate for the objectives for this modeling, i.e., to simulate DO in the releases from the units
for a wide range of conditions (i.e., hourly flows, inflow DOs, and temperature) over a period
years. Also, for most of the units studied there were four gate settings studied so there were
insufficient data to develop regression relationships between values of rh and unit velocities.
6.0
5.0
!9i
3.0
►4i
1.0
0.0
*Rhodhiss 1 O
Rhodhiss 2 El
X FC 1 •
• FC 2
O
❑ FC 3 p
A Dearborn 0 El
0
O
X
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
Vg /Vinit /Vavg
Figure 8. Relationship developed between rh and variables considered to be important for
turbine venting: Vg, gas void ratio; Vinit, initial velocity in the draft tube; and
Vavg, the average velocity in the draft tube. This relationship was used to
develop DBM for LO and MI.
Data were not available to calibrate the DBM model for Lookout Shoals (LO) because
turbine venting has not yet been installed or for Mountain Island (MI) because turbine venting
had not yet been installed at the time the studies were conducted. These facilities have short
draft tubes without the traditional relatively deep elbow and their water velocities in the
horizontal sections were lower than those for more traditional draft tubes, so the rh relationships
with initial velocity as shown for Saluda and Wylie were not used. Three of the facilities studied
did have draft tubes that had similar appearance to those for LO and MI: Rhodhiss, Fishing
Creek, and Dearborn. The rh values for these projects were higher than for those with more
traditional units. To estimate the rh values for Lookout and Mountain Island, the relationship
shown in Figure 8 was developed between rh and (Vg /Vinit/Vavg) based on the study results for
RD, FC, and DB. The DBM was then used to estimate the amount of airflow needed to attain the

DO objective and these airflow values were reviewed to assess whether they reasonably could be
provided using turbine venting. In each case the airflows were considered to be reasonable.
During model nuns (hourly time series simulations), the above curve was used as a
sensitivity analysis for the facilities listed in the legend. This was a more conservative approach
than using the bubble sizes from the calibration shown in the Table 3. While these facilities do
have draft tubes that are different from "traditional" projects, the reason is not exactly clear, and
is likely due to a combination of several factors. These factors could be:
1. Geometry of the draft tube, particularly if there is a horizontal section where bubbles can
accumulate at the top which violates the model assumptions.
2. Low average velocities in the draft tube, especially in horizontal sections — related to
point 1).
3. Low initial velocities where air is introduced tends to produce larger bubbles.
4. High gas hold up, Vg, which is the air to water ratio. The higher this value becomes, the
more likely bubble coalescence will occur, especially considering points 1, 2, and 3.
5. Low turbulence at point of air introduction. This is also related to wall roughness or the
lack of sharp (90 degree or so) bends, which also tend to keep bubbles broken up and
help prevent coalescence.
6. If bubbles and gas accumulate at the top of horizontal sections of the draft tube, then this
gas is released as very large bubbles in the tailrace, greatly reducing gas transfer.
To try to account for these effects, the correlation in Figure 8 was developed to estimate
rh values for the units studied at RD, DB, and FC for all the nuns . This was used as a sensitivity
test in addition to the results of bubble size resulting from model calibration shown in Table 3.
The air flows measured during the single unit studies are plotted versus unit flow in
Figure 9. These are the airflows that were used to calibrate DBM for each unit. Air flows are
often sensitive to TWE, so measurements of airflow were made at various TWEs for each unit
during the study and these were used to develop relationships between airflow and TWE that
were used in DBM operational nuns for total plant operations. For model nuns, TWE was
determined by using a relationship between TWE and total project flow.

350
300
250
200
O
LL
150
a
100
50
A
0 i — i tW i i 0�
1000 1500 2000 2500 3000 3500
Flow (cfs)
Figure 9. Airflows measured during the 2002 and 2006 studies
USACE "VENT" Model
® RD1
® RD2
DBU2
9 FCU1
p FCU2
❑ FCU3
p ccU1
CCU2
O WAU2
p WAU3
® WAU3, 8 Valve
® LOU2
® OXU1
p WY3
Wilhelms et al. [1987] presented a turbine venting model "VENT" based on
developments in the 1970s and 1980s by Alabama Power Company (Raney, 1975) and the U.S.
Army Corps of Engineers (USAGE). This model is a first -order gas transfer model commonly
used for simulating DO in waterways where the gas exchange coefficient is calibrated using data
from tests for that particular site. To account for the change in the gas exchange coefficient due
to various amounts of air that might be drawn into the turbine, they used the ratio of the air flow
to water flow and a coefficient of gas transfer in place of the gas exchange coefficient.
The procedure for setting up the VENT model is relatively straightforward and firstly
involves developing a pressure -time curve based on the draft tube geometry, and the "base" flow
conditions (TWE, Q, and travel time). The user then enters the boundary conditions into the
model input file (TWE, DOin, T, Q,-,t,, and Q1,,). Comparing the model to measured values, the
user can adjust two calibration parameters (see Wilhelms et al. [1987] for more details):
1. Alpha, the estimate of the gas transfer coefficient, and
2. Beta, the energy dissipation coefficient for turbulence.
Figure 7 compares the VENT DO predictions with the DBM predictions.
The DBM was selected for use because it is believed that it has several advantages over
the VENT model for predicting aeration beyond the range of conditions for which data are

available. DBM includes a more mechanistic description of the factors affecting gas transfer,
i.e., bubble size; therefore, it should provide a more robust prediction of oxygen transfer for
situations lacking data and for variable turbine venting conditions (i.e., water flow rates, air flow
rates, and draft tube geometry). The DBM also offers the capability to test sensitivity of mass -
transfer and initial bubble size to predicted conditions. Under certain conditions, the VENT
model does have reasonable predictive capabilities (Figure 7); however, it consistently
overpredicts in cases of low flows (i.e., low draft tube velocities) and in some cases very high
gas to flow ratios (Figure 7). Nonetheless, the model is used in parallel with the DBM as a cross
check.
CONCLUSIONS
Results obtained by using DBM were compared to data collected at Wylie and Saluda
Hydros. The key model inputs were the gas flow rate, water flow rate, draft tube geometry, as
well as temperature, DO, and tailwater elevation. Using measured field data from a wide range
of gate settings, an initial bubble size vs. turbine flow rate (initial water velocity at the entrance
to the draft tube) was developed. Based on correlation equations for bubble -rise velocity and the
mass- transfer coefficient developed by Wiiest et al. (1992), the model predicted the output DO at
Wylie and Saluda within 10 percent of the observed values. These results provided evidence that
the model was capable of simulating DO uptake in a robust and reliable manner that is
satisfactory for decision making regarding water quality management.
The model was then calibrated to turbine aeration data collected in 2002 for two units at
Wylie and in 2006 for twelve hydropower units at other Duke facilities. In this case, the model
was calibrated to each data point so that predictions for model nuns would be as accurate as
possible.
The discrete - bubble model has been successfully used to predict oxygen transfer in turbine
aeration applications (this work, the Saluda Project, Osage Hydro, Brownlee Hydro, and three
Mirant -NY projects), an airlift aerator (Burris et al., 2000), and a line bubble plume (Little and
McGinnis, 2001). A calibrated DBM for turbine aeration is a useful tool to predict the
effectiveness of turbine upgrades, for assessment studies for attaining DO objectives in turbine
releases, and for predicting air flows required to attain DO objectives. The model can be used
for a range of project hourly operations and water quality conditions that affect turbine aeration
performance.

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APPENDIX C
TURBINE AERATION ASSESSMENT FOR WYLIE HYDRO - 2002

TURBINE AERATION ASSESSMENT FOR
WYLIE HYDRO 2002
Prepared by
Reservoir Environmental Management, Inc
Richard J. Ruane, E. Dean Harshbarger
Andrew F Sawyer, Phil Clapp
PRINCIPIA RESEARCH CORPORATION
Charles W. Alraquist, Hubert Pearson
Prepared for
Duke Power Company

TABLE OF CONTENTS
Page
INTRODUCTION.......................................... ............................... 4
TURBINE VENTING TESTS .............................. ..............................5
TestDescription ........................................... ..............................6
Instrumentation and Procedures ......................... ..............................6
AirFlow .......................................... ..............................8
WaterFlow ....................................... ..............................8
Headwater Elevation ............................ ..............................8
Tail eater Elevation ............................ ............................... 8
Wicket Gate Position ......................... ............................... 8
Air pressure, Temperature and Relative Humidity .......................9
Headcover Pressure ............................. ..............................9
PowerOutput .................................... ..............................9
Water Temperature ............................. ..............................9
Data Reduction and Procedures for Turbine and Airflow Measurements...... 12
AirFlow .......................................... .............................12
WaterFlow ....................................... .............................12
Turbine Net Head ........... ............................... ................12
Turbine Efficiew ............................... .............................13
Correction of Turbine Efficiencv to Common Head ....................14
Tabular summaries .............................. .............................14
Results...................................................... .............................14
Induced Air Flow ................................ .............................14
Tail eater Elevation Effect ..................... .............................15
Oxygenation Efficiency ........................ .............................16
Dissolved Oxygen Uptake ................................ .............................17
Headcover Pressures ............................. .............................19
Generation Efficiew ........................... .............................19
PowerOutput .................................... .............................21
Effects of Air Valves ........................... .............................22
Turbine Venting Conclusions ............................ .............................22
WITHDRAWAL ZONE EFFECTS ...................... .............................23
CONCLUSIONS............................................ ............................... 28
APPENDICES........................................... ............................... .
A Instrument Specifications ...... ...............................
B Instrument Calibrations ..... ...............................
C Summary Data Tables ........ ...............................
D Summary of Data For Graphical Presentations........... .
2

LIST OF FIGURES
Figure Title Pate
Number
1.
Wylie Powerhouse ........................................ ..............................5
2.
4 -inch Bellmouth Flow Measuring Device ............ ..............................9
3.
6 -inch Bellmouth Flow Measuring Device ............ .............................10
4.
10 -inch Bellmouth Flow Measuring Device .......... .............................10
5.
Boat in Position for Tailrace DO Measurements ...... .............................11
6.
Effect of Wicket Gate Opening on Air Flow ........... .............................15
7.
Effect of Tailwater Elevation on Induced Air Flow, Unit 3 at 80% Gate ......
15
8.
Oxygenation Efficiency ................................... .............................16
9.
Effect of Air /Water Ratio on Oxygenation Efficiency ...........................17
10.
DO Uptake ................................................. .............................18
11.
Relationship of Air /Water Ratio to DO Uptake ....... .............................18
12.
Effect Air Flow on Headcover Pressure ................ .............................19
13.
Effect of Air Flow on Unit Efficiency, Unit 1 ....... ...............................
20
14.
Effect of Air Flow on Unit Efficiency, Unit 3 ......... .............................20
15.
Effect of Air Flow on Unit Efficiency, Unit 4 ......... .............................21
16.
Effect of Air Flow on Power Loss ...................... .............................21
17.
Tailrace Dissolved Oxygen Measurements During Generation 7/23/02 ......
24
18.
Tailrace Dissolved Oxygen Measurements During Generation-7/24/02......24
19.
Tailrace Dissolved Oxygen Measurements During Generation-7/25/02......25
20.
Tailrace Dissolved Oxygen Measurements During Generation - -- 7/26/02.....25
21.
Effect of Flow on Tailrace DO for All Units During Generation ...............26
22.
Withdrawal Zone Effects on Tailrace DO ............. .............................27
23.
Effect of Flow on Tailrace Water Temperature During Generation .............27
24.
Lake DO Profiles During Tests, Compared to Previous Years ..................28
LIST OF TABLES
Table No. Title Page
1 Differences in Turbine Units that affect Aeration Effectiveness 6
2 Instrumentation for Turbine and Airflow Measurements 7
3 Effect of Air Valve Operation on Air Flow and Power 22
4 Summary of Turbine Venting Conclusions 23

TURBINE AERATION ASSESSMENT FOR
WYLIE HYDRO - -2002
INTRODUCTION
An assessment of alternatives to provide aeration and minimum flow for Wylie tailwater
indicated that turbine venting would probably be the most cost - effective management
approach for increasing dissolved oxygen in the hydropower discharges from Wylie,
subject to additional site evaluations. A project to further evaluate this alternative was
developed by Duke Power. The objectives of this project were to
1. Determine dissolved oxygen (DO) uptake and effects of existing turbine
venting modifications on power production efficiency of units 2 & 3;
2. Determine the potential for turbine venting on units 1 & 4 and for increasing
the capability of turbine venting on units 2 & 3;
This report presents the results of field studies and analyses that address these two
objectives.
Based on the aeration assessment prepared on Wylie Hydro in January 2002, it was
determined that DO improvement in the Wylie tailwater using turbine venting would be a
result of aeration within the turbines themselves and also a result of withdrawal zone
expansion within the lake. Turbine aeration involves the addition of DO to the water
passing through the turbines by allowing air to be aspirated into the turbine system. This
air is introduced immediately below the turbine wheel where a vacuum occurs for units
having characteristics similar to those at Wylie. Withdrawal zone expansion involves the
withdrawal of water from the surface layer of the lake where DO is usually relatively
high due to contact with the atmosphere as well as due to algal production of DO.
The remainder of this report is organized as follows:
1. DO improvements attributed to turbine aeration, i.e., not including the effects of
withdrawal zone expansion,
2. DO improvements attributed to withdrawal zone expansion,
3. Conclusions, and
4. Recommendations
TURBINE AERATION TESTS
The power generating facility at Wylie Dam is composed of four hydroturbine- generator
units. Figure 1 shows the powerhouse and the discharge area of the four units. The
turbines are of the Francis type and are positioned such that under discharge conditions,
the centerline of the runners is well above the elevation of the tailwater. This
configuration suggests that turbine venting is a viable option for increasing the dissolved
4

oxygen concentration (DO) in the turbine discharge. Each of the Units is equipped with a
4 -inch diameter and a 6 -inch diameter vacuum breaker pipe through which air can be
induced into the turbine. Units 2 and 3, which are identical, have both been modified to
induce additional air by adding a 10 -inch diameter air supply pipe and a 6 -inch diameter
pipe through the Unit headcover. Both of these Units have been equipped with air valves
to control the induced airflow, but the valves on Unit 2 are not yet automated. Unit 1 is
similar in geometry to Units 2 and 3, but has not been modified to allow induce
additional air into the turbine. Unit 4 has different geometry than the other three units.
Some of the important differences in the 4 units are given in Table 1. To measure the
effects of the modifications made to Unit 3, and to evaluate the potential for turbine
venting on Units 1 and 4, tests were conducted on these three Units July 23 -26, 2002.
This report describes the tests and presents the results obtained. Since Units 2 and 3 are
identical and the air valves on unit 2 had not yet been automated, no tests were run on
Unit 2, and it was assumed that the results from Unit 3 would apply to Unit 2.
Figure 1: Wylie Powerhouse and Discharge Area
Unit
Vacuum Breaker
Pipes
Additional
Aeration Pipes
Air Valves
ExistingTurbine
Manufacturer
1
6 -inch & 4 -inch
None
NA
Alstom
2
6 -inch & 4 -inch
6 -inch & 10 -inch
Automated
Alstom
3
6 -inch & 4 -inch
6 -inch & 10 -inch
Manual
Alstom
4
6 -inch & 4 -inch
None
NA
American Hydro
Table 1— Differences in Turbine Units that affect Aeration Effectiveness

Test Description
The tests were conducted jointly by Reservoir Environmental Management Inc. and Duke
Power. The objectives of the tests were to
• Measure the amount of air induced for different turbine operating conditions.
• Measure the dissolved oxygen (DO) uptake obtained from the air induction.
• Determine the effect of the air induction on unit efficiency and power output.
• Determine the effects of aeration on DO, total dissolved gas, and temperature
in the tailrace.
Units 1, 4 and 3 were each instrumented and tested separately on July 23, 24, and 25,
respectively; and, then on July 26, Unit 3 was tested during multi -unit operation.
Instrumentation and Procedures
Most of the instruments used for airflow and turbine efficiency measurements for these
tests were temporarily installed by Principia Research Corporation for REMI with the
assistance of Duke personnel. These included instruments for determination of inlet
pressure, relative water flow rate, airflow rate, wicket gate servomotor stroke, and water
temperature. Existing, permanently installed instruments were used for the measurement
of headwater elevation, tailwater elevation, and power output. A summary of the
transducers used is presented in Table 2. Instrumentation specifications for the PRC-
supplied instruments are found in Appendix A. Calibrations for these instruments are
found in Appendix B.
Temperature, dissolved oxygen concentration (DO) and total dissolved gas concentration
(TDG) measurements used for the turbine venting tests were taken using a boat mounted
Hydrolab DataSonde& The boat was maneuvered in the tailrace so as to obtain
measurements representative of the discharge of the turbine unit being tested
With the exception of the DO, TDG, and temperature readings, test data were acquired
with a Hewlett - Packard 34970A data acquisition system controlled by Hp's Benchlink
software. As indicated in Table 2, most of the instruments employed 4 — 20 mA current
loop outputs. 250 -ohm precision resistors were used to convert the current loops to 1 — 5
V for input to the data acquisition system. The data acquisition system and control
computer were located on the generator floor near the SCADA cabinets, allowing for
easy access to the SCADA instrument loops. All transducer outputs were wired to the
data acquisition system. During most test nuns data were recorded for three minutes for
three minutes, with all channels being recorded every one second.
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Airflow
Airflows were determined by measuring the pressure drop at the entrance to bellmouth
inlets installed in place of the muffler /screen normally used at the air admission intakes.
These bellmouths were fabricated from PVC spoolpiece sections, with one flange used to
connect to the piping, and the other flange rounded on the inside to form a smooth
entrance section for the airflow. Two diametrical pressure taps were installed about one
pipe diameter downstream of the inlet, and were connected in a tee arrangement. These
bellmouths were fabricated in 4 -, 6 -, and 10 -inch diameters, matching the air supply
piping sizes. On Units 1 and 4, only the 4 and 6 -inch bellmouths were used. Unit 3 has
an additional 10 -inch air intake. Photographs of these bellmouths are shown in Figures 2,
3 &4.
Pressure readings were made using Rosemount pressure cells, with the low port
connected to the intake port tee, and the high side left open to the atmosphere.
Water Flow
The units at Wylie have no Winter - Kennedy taps for relative flow measurement.
Following previous practice, a water - flow - related differential pressure was obtained from
a tap located on the scroll case mandoor of the operating unit and a similar tap on an
adjacent non - operating unit. In this case, the pressure at the non - operating unit was
equivalent to the headwater elevation.
In an effort to eliminate the influence of trashrack losses on this measurement, a water -
filled Tygon tubing line was run from the intake gate slot to the turbine floor to provide
the high -side pressure to an additional pressure cell which was also connected to the
scroll case tap.
Pressure differentials were measured with Rosemount 3051C and ABB 624T differential
pressure transducers.
Headwater Elevation
Headwater elevation was determined from the pressure at the intake tube described
above, corrected for the turbine floor elevation. This measurement eliminates the effect
of trashrack losses on the net head determination.
The plant headwater gage was also monitored for these tests.
Tailwater Elevation
The plant tailwater gage was to be the primary tailwater elevation measurement.
However, near the end of the test program, it was determined that this gage was not
responding properly. Tailwater measurements from the tests were subsequently
determined from a Duke - supplied submersible level logger, which had been put in the
Unit 1 side of the tailrace at the start of testing.
Wicket Gate Position
The wicket gate servo stroke was measured using a Celesco cable extension transducer
( "pull -pot') mounted on one of the servos of the tested units. The transducer was
9

attached to a mounting bracket, which was clamped to a member of the wicket gate
linkage. The free end of the cable was attached to a bracket on the servo cylinder
housing. The cable was installed so that it was level and parallel to the axis of motion.
The stroke between the unit off and at full gate opening was defined as 100% stroke.
Air Pressure, Temperature, and Relative Humidity
Air pressure was measured in the wheel pit using a Rosemount model 3051C absolute
pressure cell. Temperature and relative humidity were measured in the wheel pit using
an Omega Engineering model HX -93 Temp /RH transmitter.
Headcover Pressure
It was not feasible to obtain a direct headcover pressure measurement. Instead, a pressure
tap was installed the base of the 4 -inch air admission line, and this pressure was measured
using a Rosemount 3051C pressure transmitter.
Power Output
Power output was recorded from the plant SCADA system instrument loop.
Water Temperature
Water temperature was measured using a Dwyer 3 -wire RTD transmitter immersed in
water continuously drawn from a raw water supply line on the turbine floor.
The discharge DO and temperature readings were recorded in separate files integral to the
monitors used to collect the data.
Figure 2: 4 -inch Bellmouth Flow Measuring Device
9

Figure 3: 6 -inch Bellmouth Flow Measuring Device
Figure 4: 10 -inch Bellmouth Flow Measuring Device
10

Dissolved oxygen, TDG (total dissolved gas) and temperature measurements were made
using Hydrolab® multiprobe water quality monitors. The monitor currently used to
measure DO in the tailrace is mounted on the restraining wall near the discharge from
Unit 1. This monitor was considered to be inadequate for measuring DO in the discharge
from each unit, so additional monitors were used at selected areas of the tailrace and an
additional monitor was operated from a boat, which for each test run was maneuvered
into an area, which appeared to be representative of the discharge from the unit being
tested. A photograph of the boat in position for data collection for one of the test run on
Unit 3 is shown in Figure 5. A review of the collected data and observations made of
flow patterns in the tailrace indicated that the measurements made from the boat were the
most reliable and it was these measurements which were used to calculate DO uptake and
oxygenation efficiency
Figure 5: Boat in Position for Tailrace DO Measurements
The instrumentation was installed and checked before testing was initiated. Calibrations,
especially on the bellmouth differential pressure cell were done before each set of tests
and when conditions prompted recalibration. The Hydrolab monitors deployed in the
river were pre- and post - calibrated, and the Hydrolab monitor used in the boat was also
calibrated on July 24 and July 25.
The test procedure was to establish a desired wicket gate position and wait for conditions
to stabilize before recording data. The variable which usually determined test condition
stability was tailrace DO as measured from the boat. Each test nun usually took about 10
to 15 minutes for conditions to stabilize and data to be recorded.
11

Data Reduction Procedures For Turbine and Airflow Measurements
Air Flow
Air flow into a bellmouth inlet calculated from the standard compressible flow equation
as given in ASNM's Fluid Meters:
QA =0.099702 Y d ` Fu h
I T P.
where
Q4 =air flow (scfs)
C = inlet nozzle coefficient = 0.99
Y = gas expansion factor (computed from formula, but = 1.0)
D = inside diameter of bellmouth spoolpiece (in)
Fa = thermal expansion factor = 1.0
H4 = pressure differential for given flow nozzle (in H20)
pa = air density in wheel pit (computed from air density equation) (lbm /ft)
Water Flow
Water flow through a turbine was estimated from the scroll case differential pressure by
the following equation:
QTF = C hip,
where
QTT- water flow rate (cfs)
C flowmeter coefficient (= 707)
hTT- measured head difference across the flowmeter taps (in H20)
Based on previous test results, the coefficients C were chosen to yield a peak efficiency
for each unit of about 95 %.
Turbine Net Head
Turbine net head is computed as follows
Inlet static head, hzs:
his = hi + ZI
where:
hl = inlet static head measured at pressure cell elevation (ft H20)
ZI = elevation of pressure cell (= 525 ft)
12

Inlet velocity head, HTT
1 �rr
Hr7 _ —
2g AI
where
QTT- = water flow rate (cfs)
AI = intake area ( = 705W)
g = acceleration of gravity (= 32.14 ft/s2)
Inlet total head, HI:
HI = h, + Hr7
Discharge static head, hd:
ha = HTTr
where
HTTT- = tailwater elevation (ft)
Discharge velocity head, HlT):
1 Qrr
Hr� _ —
2g Are
Ad = area at the draft tube opening to the tailrace ( = 525.4 ft2)
Discharge total head, Hd:
HD= hf) + HT T)
Turbine net head at test conditions, HT:
HT =H1 –HD
Turbine Efficiency
Turbine efficiency, q is computed from
=737.6 PT
PgO T1,HT
13

where turbine power PT is given in kilowatts, and other terms have been defined
previously.
Correction of Efficiency Test Results to Common Head
Turbine Mode
The measured flow rate and turbine power output at the test head is corrected to a
common head, H,, by:
o
H,
Q:— QT HT
H
4P =PT
7) HT
No correction is required for efficiency.
Test results were corrected to a common head of 72 feet for all tests.
Tabular Summaries
Tabular summaries of the data collected and computations are given in Appendix C.
Graphical interpretations of these data are given elsewhere in this report.
Results
Summary tables of the data used for the graphical presentations of turbine venting results
in the report are provided in Appendix D. The values shown in the tables are the
averages of the recorded data for the test nuns. A review of the DO and water
temperature data indicated that the data collected from the boat in the tailrace were the
most representative, therefore these data were used to calculate oxygenation efficiencies
and DO uptake.
Induced Air Flow
Induced airflow measured for each of the three units tested is shown on Figure 6 as a
function of wicket gate opening. These data indicate that:
90 to 142 sfcs of air was induced into the modified unit (Unit 3), as compared to
50 -60 scfs on the un- modified similar unit (Unit 1)
2. The maximum amount of air was induced into Unit 3 at best gate operation (near
80 percent wicket gate opening),
3. The amount of air induced into Unit 1 decreased slightly as gate opening
increased.
4. Less than 20 scfs of air was induced into Unit 4, and air flow stopped entirely at
80 percent wicket gate opening
14

160
140
120
100
v
a
80
O
LL
L
Q 60
40
20
0
0
Unit 1
—(k -Unit 3
Unit 4
Unit 3 - Multi -Unit Operation
10 20 30 40 50 60 70 80 90 100
Gate Opening ( %)
Figure 6: Effect of Wicket Gate Opening on Air Flow
Tailwater Elevation Effect
Included on Figure 6 are six data points obtained when additional units were operated
along with unit 3. These data indicate that air induced into unit 3 decreased when the
other units were operated. Data obtained from these multiunit tests are included on
Figure 7 which shows that as tailwater increased (due to multi -unit operation) the airflow
induced through unit 3 operating at 80% gate opening decreased.
160.0
140.0 II
120.0
85
IM
100.0
v
p 80.0
LL
Q
60.0
40.0
20.0
0.0
495 496 497 498 499 500
Tailwater Elevation, msl
Figure 7: Effects of Tailwater Elevation On Induced Air Flow, Unit 3 at 80% Gate
15

Oxygenation Efficiency
Oxygenation efficiency, Eo is defined as the mass of oxygen available in the induced air
divided by the mass of oxygen added to the turbine discharges. To obtain the mass of
oxygen that was added to the turbine discharges, the concentration of DO measured in the
tailrace with and without airflow was multiplied by the water flowrate to determine the
mass rate of oxygen.
Oxygenation efficiency as a function of wicket gate opening is shown on Figure 8.
Overall, the efficiency for all three units tested was about 25% and was about 20 % at 80
% wicket gate opening.
Eo is a function of the following variables: the DO concentration in the draft tube, the
saturation concentration for DO in the draft tube, the travel time of the air /water mixture
through the draft tube, the depth of the tailrace, the pressure of the air /water mixture, the
ratio of the air to water flow rates in the draft tube and the distribution of air and water in
the draft tube.
45.0
40.0
35.0 *Unit 1
(kUnit 3
v 30.0 A Unit 4
C
N
25.0
LU
C
0 20.0
R
C
N
15.0
K
O
10.0
5.0
0.0
0 10 20 30 40 50 60 70 80 90 100
Wicket Gate Opening, %
Figure 8: Oxygenation Efficiency
The relationship between oxygenation efficiency and air /water flow ratio is shown on
Figure 9. The data from all three units appear to follow a more or less linear relationship
and indicate that the oxygenation efficiency was more affected by air /water ratio than by
individual unit characteristics and /or geometry.
16

Figure 9: Effect of Air/Water Ratio on Oxygenation Efficiency
Dissolved Oxygen Uptake
Dissolved oxygen increases in the turbine discharge as a function of wicket gate opening
are shown on Figure 10. As might be expected, the DO uptake for unit 3 was greater than
for the other two tested units, and the uptake for unit 4 was less than for the other two
units. Uptake for unit 3 ranged from about 3.5 to 2.0 mg /L, for unit 1 from about 2.3 to
1.0 mg/L, and for unit 4 from about 0.7 to 0 mg /L. For all three units, DO uptake
decreased with wicket gate opening.
Also included on Figurel0 are DO uptakes for unit 1 with unit 4 operating and for unit 3
with unit 1 operating. These data indicate that operating unit 4 had little effect on DO
uptake for unit 1, but that in most cases, the uptake for unit 3 dropped about lmg /L when
unit 1 was operating. This decrease may be due to a number of factors:
• The local effect of tailwater elevation on the amount of air induced
• Mixing of the discharges in the tailrace before measurements were taken
• The withdrawal zones changing in the reservoir when units near one another are
operated.
• The DO in unit 3 increasing during the tests when Unit 1 was operating
Figure 11 shows the effect of air /water flow ratio on DO uptake for all three units tested.
Considering the data from all three units as a continuous curve, these data indicate that
the relationship was not linear, but that uptake may approach a maximum as the air /water
ratio increases (i.e., for air /water ratios greater than about 5 percent, the effect of more air
17

does not increase the DO linearly.) This non - linear relationship could be caused by the
increase in the DO concentration. Aeration rates typically follow first -order reaction
kinetics that depends on the saturation concentration of DO.
4.00
3.50
3.00
2.50
E
ti
2.00
C.
M
0 1.50
1.00
0.50
0.00
*Unit 1
k4
Unit 3
A Unit 4
Unit 1 with Unit 4 on
Unit 3 with Unit 1 on
G
10 20
30 40 50 60 70
Wicket Gate Opening, %
Figure 10: DO Uptake
80 90 100
5.00
4.50
*Unit 1
4.00
(Unit 3
5 U n it 4
3.50
(i
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E
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G.
7
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0
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1.00
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0.00
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0
Air /Water Ratio, %
Figure 11: Relationship of Air/Water Ratio to DO Uptake
18

Headcover Pressures
Figure 12 shows headcover pressures as a function of wicket gate opening measured both
with and without the air valves open. Negative pressures under the headcover with the
air valves open indicate that additional air could be induced if piping were installed to
admit more air.
The data with the air valves open show headcover pressures of about —5 feet of water for
unit 1, -2feet of water for unit 3 and -1 feet of water for unit 4. These data indicate that
potentially more air could be induced into units 1 and 3 if more air passages were
installed, although the increase may not be great for unit 3. Since the data show very
little negative pressures for unit 4, the installation of additional air piping would not help
induce more air. It may however be possible to get more air into unit 4, by making
turbine modifications such as installation of hub baffles to decrease headcover pressure.
-25.0
y -20.0
C-7
LL -15.0
ti
a
a
N
CL -
L 10.0
O
v
= 5.0
0.0
0 10 20 30 40 50 60 70 80 90 100
Wicket Gate Opening, %
Figure 12: Effect of Air Flow on Headcover Pressure
Generation Efficiency
The effect of the airflow on generation efficiency can be ascertained by comparing
generation efficiency with and without air induction. The data on Figures 13, 14 & 15
indicate that the induced air reduced generating efficiency by about 3 -5 percent on unit 1,
about 6 -11 percent on unit 3 and 1 -2 percent on unit 4.
19

100
95
N 90
r
NN�
j� 85
v
C
N
W 80
75
70 L
0
100
95
d 90
r
NN�
1.1.
85
v
C
d
W 80
75
70 L
0
OAir Off
Air On
2 4 6 8 10 12 14 16 18 20
Power Output (MW)
Figure 13: Effect of Air on Unit Efficiency, Unit 1
*Air Off
Air On
2 4 6 8 10 12 14 16 18 20
Power Output (MW)
Figure 14: Effect of Air on Unit Efficiency, Unit 3
20

100
95
N 90
r
NN�
j� 85
v
C
N
W 80
75
70 L
0
9Air Off
Air On
2 4 6 8 10 12 14 16 18 20
Power Output (MW)
Figure 15: Effect of Air on Unit Efficiency, Unit 4
Power Output
As shown on Figure 14, maximum power output for unit 3 (the only one tested at 100%
gate) was reduced about 1.5 mw by the presence of the air.
5
5
♦Unit1 i#
4
IUnit3
A Unit 4
4
2 3
V! �
V!
3
J 0 �
L
0 2
a
2
s�
1 ♦♦
1
0
0 20 40 60 80 100 120 140 160
Air Flow, cfs
Figure 16: Effect of Air Flow on Power Loss
21

Figure 16 shows the effect of airflow on measured power loss for the three units. There
is significant scatter in the data, particularly for unit 3, but a linear relationship could be
assumed which would indicate about I mw loss for every 40 cfs of air induced.
Effect of Air Valves
Table 3 shows data from special tests when various combinations of air valves were
operated on Unit 3. During these tests, Units 3, 1 and 4 were all operating at 80% wicket
gate opening and the tailwater elevation was at about 498.9. These data indicate that
most of the air was going through the 10 -inch valve. Since a significant part of the noise
associated with the air induction appeared to come from the operation of the smaller
valves, it could be possible to reduce noise levels somewhat without significantly
affecting airflow by closing the 4 and 6 -inch valves. The data collected were not
sufficient to determine if power output was affected by the use of different air valves.
Air Valves Open
Air Flow
(cfs)
Power Output
(MW)
10 -inch, 6 -inch & 4 -inch
97
15.7
4 -inch & 6 -inch
54.6
16.7
10 -inch
93.1
15.2
6 -inch
31
17.2
4 -inch
28.4
17.2
Table 3: Effect of Unit 3 Air Valve Operation on Air Flow and Power
Turbine Aeration Conclusions
The following conclusions only address the results of the turbine aeration tests for each
unit. It should be noted that aeration considerations for the whole plant should take into
account the effects of all the units for the plant as well as the results of withdrawal zone
expansion as discussed in the next section.
Unit 1
• There was sufficient negative headcover pressure to induce more air if air supply
piping is added.
• Turbine modifications, for example the addition of hub baffles, could increase
suction— consideration should be given to adding hub baffles to reduce the effects
of increased tailwater elevation when multiple units are operated.
Unit 3
• Significant amounts of air, enough to increase the DO in the tailrace by as much
as 3.5 mg /1, was induced into Unit 3.
• This increase in DO came at a cost of 5 -6 % loss in unit efficiency.
• Induced air reduced maximum power output by about 1.5 mw when the unit was
operated near 80% wicket gate opening.
22

• Tailwater elevation increases caused by operating additional units reduced
airflow.
• The effect of introducing additional air may not result in significantly raising
tailrace DO, but could significantly affect power efficiency losses.
Unit 4
Very little air was induced into Unit 4.
The data indicate that there is not sufficient suction under the headcover to induce
air without turbine modifications.
A summary of the general conclusions is presented in Table 4
Unit
Amount of
Amount
TW
Would
Would
Power
No.
Air Flow
of DO
Elevation
Modifi-
Additional
Losses
Induced
added at
(Multi -unit
cation
Air Pipes
Presently
80%
operation)
Potentially
Increase Air
Caused by
gate,
Effects On
Increase
Flow?
Air Flow
mg /L
Air Flow
Air Flow?
1
Moderate
1.0
Significant
Yes
Probably
Moderate
3,2
Significant
2.6
Significant
Marginal
No
Significant
4
Very Small
0
Unknown
Yes
Not without
Small
modification
Table 4: Summary of Turbine Aeration Conclusions
WITHDRAWAL ZONE EFFECTS
The previous section presented the results of turbine aeration on DO uptake attributed
only to the effects of absorption of air that was drawn into the turbine. This section
presents the effects of withdrawal zone expansion from within the lake on the DO
increase in the tailwater as well as the overall DO increase in the tailwater that can be
attributed to both of these factors.
Figures 17 through 20 present the results of DO measurements in the tailrace during the
tests discussed in the previous section. It is important to note that the DO measured in
the tailrace during the tests on Units 1 and 3 were generally equal to or greater than 5
mg /L (see Figures 17 and 19.) Figure 20 presents the results of the tests on July 26 when
three and four units were operated, and these results showed that DO in the tailrace
averaged about 6 mg /L when Units 1,2,3 were operated. These results also showed that
even though Unit 4 drew little air, the DO in the tailrace was about 5.5 mg /L when Unit 4
was operated with Units 1,3 and Units 1,2,3. These DO values are considerably greater
than the DO uptake measurements that were attributed to turbine aeration alone, e.g., the
DO uptake values attributed to aeration in the discharges from Units 1 and 3 were about 1
and 2.5 mg /L, respectively, when the gate settings were about 80 percent (see Figure 10.)
23

The results of the tests from the individual units are summarized in one plot on Figure 21.
o Unit 1 -no air a Unit 1 -with air A Unit 1 Flow m Unit 4 Flow
8 8000
8
7
7000
8000
7
6
7000
6000
rn
E
6
5
v
6000
rn
E
3
OX 4
y
5
N
�
4
4000 LL
v
5000
V
3
4000
ox
0 3
O O
O C
3000 F
A
LL
N
F
0 3
O O
O O
O
3000
2
2
2000
2000
1
1
1000
0
1000
12:00 13:00 14:00 15:00 16:00 17:00
7/24/2002
0 0
12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00
7/23/2002
Figure 17:Tailrace Dissolved Oxygen Measurements During Generation- 7/23/02
o Unit 4 -no air Unit 4 -with air m Unit 4 Flow A Unit 1 Flow
8 8000
7
7000
6
6000
rn
E
5
v
5000 v
�
3
OX 4
4000 LL
v
0 3
3000 F
A
N 8
O O
O O
O
2
2000
1
1000
0
0
12:00 13:00 14:00 15:00 16:00 17:00
7/24/2002
Figure 18: Tailrace Dissolved Oxygen Measurements During Generation- 7/24/02
24

o Unit 3 -no air Unit 3 -with air Unit 3 Flow A Unit 1 Flow
7 7000
6 6000
rn
E
5 5000
O
0 3
OX 4 0 4000 LL
m
0 3 O O O 0 3000 0
N V A
fA O
2 2000
1 1000
0 0
10:00
11:00 12:00 13:00 14:00 15:00 16:00 17:00
7/25/2002
18:00
Figure 19: Tailrace Dissolved Oxygen Measurements During Generation- 7/25/02
Figure 20: Tailrace Dissolved Oxygen Measurements During Generation- 7/26/02
25
O Unit 1 no air Unit 1 -With Air -Unit 2 -With Air Unit 3 -No air
Unit 3 -With Air (. Unit 4 -No Air Unit 4 -With Air ,Total Flow
8
16000
7
14000
All Four
6
Units - 80 %Gate
12000
1, 2 & 3 - 80 %Gate
Units 1, 3 & 4 - 80%
Gate Units
OI
E
5
10000
OI
a
4
8000
O
0
v
R
> 3
6000 F
O
W
A
2
4000
1
2000
0
0
12:00 13:00 14:00 15:00 16:00
7/26/2002
Figure 20: Tailrace Dissolved Oxygen Measurements During Generation- 7/26/02
25
O Unit 1 no air Unit 1 -With Air -Unit 2 -With Air Unit 3 -No air
Unit 3 -With Air (. Unit 4 -No Air Unit 4 -With Air ,Total Flow
e
All Four
Units - 80 %Gate
1, 2 & 3 - 80 %Gate
Units 1, 3 & 4 - 80%
Gate Units
Figure 20: Tailrace Dissolved Oxygen Measurements During Generation- 7/26/02
25

Figure 21:Effect of Flow on Tailrace DO for All Units During Generation
It is also important to note that the DO in the tailrace during tests when air was not
admitted to the units varied significantly between the units, e.g., at 80 percent gate the
DO in the tailrace of Unit 1 was 3.8 mg /L, for Unit 3 it was 3.2 mg /L, for Unit 4 it was
2.5 mg/L, and for Units 1,3,4 it was about 4.5 mg /L. These results show that the
withdrawal zone expansion varies between units and increases as the total flow through
the project increases.
Figure 22 shows the estimated amount of DO increase in the discharges from the various
units that can be attributed to withdrawal zone expansion. These results are consistent
with measurements made by Duke Power at various projects on the Catawba River
(Knight, 2002) as well as measurements made at TVA projects (Roane et al, 1993.)
Figure 23 shows how temperature in the discharges from Units 1, 3, and 4 increased as
unit flow increased, and these results help confirm that withdrawal zone expansion
caused the DO to increase in the turbine discharges.
Although withdrawal zone expansion is a significant consideration for achieving DO
standards, the amount of DO that can be contributed to the turbine discharges from the
project is dependent on water quality conditions in the lake. Figure 24 presents a
summary of DO profiles that have been collected in the forebay of Lake Wylie during the
months of July and August for the period 1993 through 2001, and the conditions during
the 2002 turbine venting tests are plotted along with the historical profiles.
These profiles indicate that the 2002 tests were conducted under worse or "near- worse"
DO conditions in Lake Wylie. In comparing DO conditions in the lake and their potential
negative impact on DO in the turbine discharges, it should be noted that worse case
conditions occur when low DO near zero occurs high in the water column and /or when
26
O Unit 1 Air Off ♦ Unit 1 Air On Unit 3 Air Off Unit 3 Air On Unit 4 Air Off Unit 4 Air On
7.0
6.5
6.0
5.5
E
♦
y 5.0
♦
�
a
4.5
♦
0
v
4.0
O
O
H 3.5
n
O
p
3.0
O
2.5
2.0
1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800
Total Water Flow (cfs)
Figure 21:Effect of Flow on Tailrace DO for All Units During Generation
It is also important to note that the DO in the tailrace during tests when air was not
admitted to the units varied significantly between the units, e.g., at 80 percent gate the
DO in the tailrace of Unit 1 was 3.8 mg /L, for Unit 3 it was 3.2 mg /L, for Unit 4 it was
2.5 mg/L, and for Units 1,3,4 it was about 4.5 mg /L. These results show that the
withdrawal zone expansion varies between units and increases as the total flow through
the project increases.
Figure 22 shows the estimated amount of DO increase in the discharges from the various
units that can be attributed to withdrawal zone expansion. These results are consistent
with measurements made by Duke Power at various projects on the Catawba River
(Knight, 2002) as well as measurements made at TVA projects (Roane et al, 1993.)
Figure 23 shows how temperature in the discharges from Units 1, 3, and 4 increased as
unit flow increased, and these results help confirm that withdrawal zone expansion
caused the DO to increase in the turbine discharges.
Although withdrawal zone expansion is a significant consideration for achieving DO
standards, the amount of DO that can be contributed to the turbine discharges from the
project is dependent on water quality conditions in the lake. Figure 24 presents a
summary of DO profiles that have been collected in the forebay of Lake Wylie during the
months of July and August for the period 1993 through 2001, and the conditions during
the 2002 turbine venting tests are plotted along with the historical profiles.
These profiles indicate that the 2002 tests were conducted under worse or "near- worse"
DO conditions in Lake Wylie. In comparing DO conditions in the lake and their potential
negative impact on DO in the turbine discharges, it should be noted that worse case
conditions occur when low DO near zero occurs high in the water column and /or when
26

DO is low (i.e., 5 to 6 mg /L) in the upper part of the water column (i.e., the upper 4 to 6
m.). The profiles for 2002 indicate that DO in the upper part of the water column near
the surface was near normal conditions; however, the low DO in the bottom layers of the
lake deeper than 8 m was as low as any preceding year (i.e., the profile observed on July
8, 1993.)
Figure 22: Withdrawal Zone Effects on Tailrace DO
O Unit 1 Air Off ♦ Unit 1 Air On _. Unit 3 Air Off Unit 3 Air On 0 Unit 4 Air Off o Unit 4 Air On
DO added to the discharge from individual units due to withdrawal zone
expansion during the 2002 study (assuming baseline DO would be 1 mg /L in
the turbine discharges without withdrawal zone expansion)
4.0
28.3
3.5
�
♦ Unit 3
3.0
is Unit 1
E
L
n
Unit 4
O
2.5
❑ Unit 1 w/ 4
♦ ffi.
c
2.0
*
O Unit 3 w/ 1
y
Units 1,3,4
28.0
m
1.5
— Linear (Unit 1 )
U
Q
— Linear (Unit 3)
1 .0
---- -- Linear (Unit 4)
E
O
♦
— Linear (Unit 3 w/ 1 )
0.5
v
i
0.0
1000
1500 2000 2500 3000 3500 4000
Unit Discharge, cfs
Figure 22: Withdrawal Zone Effects on Tailrace DO
Figure 23: Effect of Flow on Tailrace Water Temperature During Generation
27
O Unit 1 Air Off ♦ Unit 1 Air On _. Unit 3 Air Off Unit 3 Air On 0 Unit 4 Air Off o Unit 4 Air On
28.5
28.3
L
n
U
♦ ffi.
28.0
Q
O
E
O
♦
v
27.8
n�
r
27.5
1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800
Total Water Flow (cfs)
Figure 23: Effect of Flow on Tailrace Water Temperature During Generation
27

Comparisons between 2002 profiles and historical July /August DO Profiles Collected in
Wylie Forebay -- indicates
that 2002 conditions were "worse or near - worse"
conditions
0
2
4
6
E 8
a 10
08/01/1995
-- 07/16/1996
_-
`� �-'
�
-
N
- -- 08/19/1997
� ,''� •
12
08/13/1998
08/04/1999
14
08/01 /2001
� • `��`" •
--------------------------
-
-
--- 07/22/2002
� • '_
16
-
-
-
07/24/2002
07/26/2002
18
- 7/8/93
20
0 1 2
3 4 5 6 7 8 9
Dissolved Oxygen (mg /1)
Figure 24: Lake DO Profiles During Tests, Compared to Previous Years
In determining worse case conditions, the temperature profile for the forebay must also
be considered because it affects the density of the water layers and therefore the
withdrawal zone expansion. Withdrawal zone modeling is needed to estimate the DO in
the discharges considering the various DO and temperature profiles in the lake and then
to determine which profile conditions yield the worse case DO conditions for the turbine
discharges (Note to Duke reviewers: this modeling was supposed to be conducted under
an expanded scope for this project during fiscal year 2002, but it was not completed by
under the 2002 budget.)
CONCLUSIONS
It appears that turbine aeration using air aspiration in conjunction with withdrawal zone
expansion can achieve the DO water quality standard during periods when the turbines
are operated, as long as Unit 4 is operated only after units 1, 2, and 3 are given preference
for being operated first before Unit 4 is operated. However, it is conceivable that the
amount of DO added using withdrawal zone expansion may not be sufficient under some
conditions in the lake when DO is low in the upper layer of the lake or when low DO
occupies a greater volume of the bottom of the lake than was observed during this study
or any other time recorded in the past.
If additional aeration is needed to achieve the DO standard, the following additional
turbine aeration measures could be considered:
• Adding more air supply piping and consider turbine modifications on Unit 1
• Investigating modifications to Unit 4 to induce more air.
28
08/01/1995
-- 07/16/1996
_-
`� �-'
�
-
-
- -- 08/19/1997
� ,''� •
i
08/13/1998
08/04/1999
08/01 /2001
� • `��`" •
--------------------------
-
-
--- 07/22/2002
� • '_
-
-
-
-
07/24/2002
07/26/2002
- 7/8/93
Figure 24: Lake DO Profiles During Tests, Compared to Previous Years
In determining worse case conditions, the temperature profile for the forebay must also
be considered because it affects the density of the water layers and therefore the
withdrawal zone expansion. Withdrawal zone modeling is needed to estimate the DO in
the discharges considering the various DO and temperature profiles in the lake and then
to determine which profile conditions yield the worse case DO conditions for the turbine
discharges (Note to Duke reviewers: this modeling was supposed to be conducted under
an expanded scope for this project during fiscal year 2002, but it was not completed by
under the 2002 budget.)
CONCLUSIONS
It appears that turbine aeration using air aspiration in conjunction with withdrawal zone
expansion can achieve the DO water quality standard during periods when the turbines
are operated, as long as Unit 4 is operated only after units 1, 2, and 3 are given preference
for being operated first before Unit 4 is operated. However, it is conceivable that the
amount of DO added using withdrawal zone expansion may not be sufficient under some
conditions in the lake when DO is low in the upper layer of the lake or when low DO
occupies a greater volume of the bottom of the lake than was observed during this study
or any other time recorded in the past.
If additional aeration is needed to achieve the DO standard, the following additional
turbine aeration measures could be considered:
• Adding more air supply piping and consider turbine modifications on Unit 1
• Investigating modifications to Unit 4 to induce more air.
28

APPENDIX D
REFERENCED CORRESPONDENCE

Alk
Mr. Mark Oakley
Relicensing Project Manager
C atawba-Wateree Hydroelectric Project
P-0. Box 1006
Mail Code EC12H
526 South Church Street
Charlotte, North Carolina 28201
RE: First Stage Consultation Comments and Request for Studies, Catawba-Wateree ;
Hydroelectric Project (FERC ProjectNo. 2232), North Carolina and South. Carolina.
Dear Mr. Oakley:
The Catawba-Waterce Project
The Catawba-Wateree Project is comprised of thirteen hydropower plants and eleven reservoirs. The
Project spans over 200 miles of river and encompasses approximately 1,700 miles of shoreline
within nine counties in North Carolina (Alexander, Burke, Caldwell, Catawba, Gaston, Iredell,
Lincoln, McDowell, and Mecklenburg) and five counties in South Carolina (Chester, Fairfield,
Kershaw, Lancaster, and York). The Proj ect consists of the Bridgewater, Rhodhiss, Oxford, Lookout
---Sh-oalsp-Cowans--Ford,-and--Mountain-Island-Developmunts-in-Nor-th--C-arollna,-and-W-ylie�-F-ishing-

Creek, Great Falls-Dearborn, Rocky Creek-Cedar Creek, and Wateree Developments in South
Carolina. The Catawba River originates in the Blue Ridge Mountains in North Carolina and flows
south to its confluence with the Big Wateree Creek and forms the Wateree River in South Carolina.
The Wateree River flows to its confluence with the Congaree River and forms the Santee River
which flows to the Atlantic Ocean. The Santee River is impounded at river mile 87 by the Santee-
Cooper Hydroelectric Project. The Catawba Wateree Project =s total drainage area as measured at
the Wateree Development is 4,750 square miles.
Project reservoirs support warm water fisheries, andTeservoir shorelines provide important foraging,
nesting and other habitat for terrestrial wildlife and migratory birds. Reservoir tailwaters support
cold-, cool-, and warm-water fisheries. The aquatic and terrestrial wildlife that live within the
Project=s boundaries are dependent upon the shoreline and permanent source of water for aquatic
habitat. The Services are very interested in ensuring that the Project is managed in a way that
protects fish and wildlife resources.
Project History
The Catawba-Wateree Hydroelectric Project has effectively impeded and fragmented approximately
220 miles offlowing river. Historically, anadromous fish migrated upstream to the Piedmont region
of the Catawba River and some continued into North Carolina. Today diadromous fish spawning
migrations are impeded at the Wateree Darn, the furthest downstream dam within the project. In
addition, many miles of riffle/shoal habitat, important not only for anadromous fish spawning but
also for riverine fish habitat, have been affected by impoundments and diversions. Accordingly,
there are several existing reaches within the project that are of particular importance to the Services
due to their potential for habitat restoration. These areas include the 35 miles of free flowing river
below the Bridgewater Development, the 39 miles of free flowing river below Lake Wylie, the de-
watered Great Falls bypass, the 76 miles of free flowing river below the Wateree Dam, as well as the
major tributaries of the system. The Services believe there is potential for restoration and
enhancements within these areas that would greatly benefit diadromous fish, resident fish, and
terrestrial and avian wildlife.
Fish and Wildlife Service Management Goals
The Services= general management goals and obj ectives for the Catawba and Wateree Rivers, are to
protect and enhance a balanced, diverse fish community and the diversity of aquatic habitats on
which that community depends, as well as to provide safe and effective upstream and downstream
passage and habitat for diadromous and migratory game and non-game fish species. Further goals
include the recovery of diadromous fish populations ofthe Santee-CooperBasin (which includes the
Catawba-Wateree sub-basin) to levels that provide economic, social and ecological values and the
protection and recovery of endangered species. An Interagency Santee-Cooper Basin Diadromous
Fish Passage and Restoration Plan which identifies these resource goals has been accepted by the
FERC as a Comprehensive Plan under Section 10(a)(2)(a) ofthe Federal PowerAct andFERC Order
No. 481-A. The Catawaba-Wateree Hydroelectric Project and other hydroelectric projects have
IR

disproportionately eliminated and cumulatively affected riffle and shoal habitats in the Catawba -
Wateree River watershed. Therefore, restoration, protection and/or enhancement of certain habitats
types (i.e., riffles and shoals) is a priority goal for the Fish and Wildlife Service, Identification of
opportunities for the protection and enhancement of valuable wildlife habitat and enhancing potential
use-of public trust waters for recreation are additional resource goals of the Fish and Wildlife
Service. The Fish and Wildlife Service is of the view that a licensee should be responsible for the
management costs associated with the protection and utilization of the public trust resources it
utilizes.
The studies recommended below will allow the Fish and Wildlife Service to gather necessary
information to foster the above goals.
Ur
bytheProject.
NOAA Fisheries= primary and general goal, with respect to the relicensmg of the Project and fishery
resources of the Wateree- Catawba Basin, is to promote protection, management, and restoration of
self sustaining diadromous fish populations to fully utilize available habitat and production
capability, to restore species diversity, and to sustain viable fisheries. Diadromous species of special
interest include but are not limited to American shad, river herring and other alosids, striped bass,
American eel, Atlantic sturgeon, and the federally hsted.endangered shortnose sturgeon. Although
unquantifi.ed in economic terms- the forage base provided by shad and other alosid species supports
(or limits, if depressed in numbers) extremely valuable marine commercial and recreational fisheries
of the Atlantic coast.
The specific goals _include the following:
3
I
Conserve Species. Avoid further declines and/or extinction and foster long -term
survival and recovery of Santee- Wateree- Catawba Basin American shad, river
herring, striped bass, American eel, Atlantic sturgeon, and shortnose sturgeon.
Conserve Riverine, Estuarine, and Marine .Ecosystems. Conserve the riverine
ecosystem and the vital link to marine ecosystem health provided by diadromous
species.
3 Balance the Life Cycle Needs of Other Species. Ensure that diadromous fish
conservation measures are balanced with the management and conservation needs
of other native fish and wildlife species.
3 Support SustainableRecreational and Commercial Fisheries. Provide for adequate
fish passage and access to essential habitats to support a sustainable shad and herring
fishery, and the contribution of alosid species to sustainable fisheries for other
species and to a healthy estuarine and marine ecosystem.
3
I

X. I I . I -
ZEM
Quantify diadromous fish utilization of the Wateree River below Wateree .7Darn. utilizing
standard fish sampling gear (e.g., electrofishing, gill nets, etc.). The most effective and
efficient methods of sampling should be determined in consultation with the state and
Federal natural resource agencies.
Justification. The Wateree River contains 76 miles of free-flowing riverbelow the Wateree
Dam to its confluence with the Congaree River. Historically, anadromous fish migrated up
the Wateree River to the Piedmont reaches of the Catawba River. The project has blocked
and fragmented historical migration patterns for all diadromous species including American
shad, blueback herring, -striped bass, American eel, and shortnose sturgeon. The shortnose
sturgeon is a federally listed endangered species and all federal agencies (including the
FERC) are responsible for undertaking actions toward its recovery under Section 7(a)(1) of
the Endangered Species Act (16 U.S.C. 1531-1543). This studywill aid in the determination
of the need for a fish passage facility at Wateree Dam.
6. - Basin Wide Fish Passage Feasibility Study
Determine the feasibility including the design, location, and engineering considerations and
constraints of installation of an upstream and/or downstream fish passage facility at each
hydropower development within the project.
Justification. Diadromous and potamodromous fish populations within the Santee-Cooper
Basin, including the Catawba-Wateree sub-basin have significantly declined within the last
century. There are Federal Interstate Fishery Management Plans which outline mechanisms
of recovery, including fish passage at hydroelectric facilities. Diadromous species
historicallymigrated up the Wateree River to the Catawba River but have been blocked and
fragmented by the series of dams and reservoirs which constitutes the project. This study
will determine the feasibility of fish passage facilities throughout the proj ect to provide fish
access to stone SP
lop I I
Provide quantitative and qualitative data in GIS format of the available and potential
spawning, rearing and foraging habitats (i.e., -riffles/shoals, open water habitat, shallow cove
areas) throughout the proj ect, including tributaries for diadromous and resident fish species.
Justification. Information is needed on the existing available diadromous and resident
fishery spawning, rearing, and foraging habitat and candidate areas for restoration throughout
the project. This information will aid in the assessment of project impacts on aquatic
rd

resources, determination of the need for fish passage, possible development of fish species
target numbers, potential habitat restoration areas, and alternative mitigation alternatives. -
Previous studies on other projects have modeled the system to determine what portion
of the watershed was being separated or Adelinked_= from the rest of watershed. As
part of -its study, the applicant should conduct a literature review to determine the
characteristics of the watershed, as well as the distribution of species and patterns of
aquatic communities in the Catawba-Wateree watershed.
Aa a first step, the applicant could examine historical fish and mussel collections to
determine where species have been extirpated or exist only in low numbers. A
diadromons %h species review could begin by examining historic literature in -local
libraries and newspapers, as well as legal records.
R

This study could be developed in phases, with Phase I work to include literature
review; habitat characterization on a macro level; and ranking of tributaries. A draft
study plan should be developed and reviewed by the natural resource agencies.
M
Explore alternative release schedules which would diminish the affects onriverine resources
from peaking operations.
Justification. Peaking operations modify downstream environments by scouring bed
sediments, and altering the magnitude, duration, and timing of instream flows. These
releases generate rapid changes in velocity, depth, and Water chemistry, adversely affecting
downstream aquatic species and their habitats. Recruitment offiverine species below dams
of peaking operations is low due to the highly variable conditions and the downstream
transport of eggs and larvae. Alternatives to current project operations are necessary to
determine possible restoration and/or enhancement measures.
10. Out-migration and Entrainment/Mortality Study
An evaluation of existing and potential resident and diadromous fish out-migration and
entrainmeaVmortality at each of the project dams is needed to assess proicct-related factors
influencing fish populations in the river basin. Out-migration (spillway and turbine passage) may
be significant in terms of recruitment for river basin populations. An understanding of existing
and potential out-migration and turbine passage is needed in connection with diadromous fish
passage feasibility analyses at the project.
The out-migration study should include the frequency and characteristics of spillway water
releases with respect to potential out-migration by target resident and diadromous fish
species at the project dams. Limnological studies should be included that document monthly
changes in dissolved oxygen, ternperature, conductivity, turbidity, thermocline development
and overturn under normal hydropower operations. This study element should include
-vears -of d-ata-to-help-pwvide-an-under-standing-of-limnology--,mdkabilaLconditions
—multiple �
likely to be encountered by outmigrating adult, j uvenile, and egg/larval -fish life stages at the
project dams.
A literature based study summarizing entrainment mortality studies on similar projects
should be conducted. The database on existing entrainment and mortality studies has been
greatly enhanced by the Aclass of 93" relicensings. it is conceivable that a sufficient
database exists on similar sites with similar turbines from which to draw reasonable
conclusions relative to entrainment and mortality in lieu of conducting a site-specific study.
The Services are amenable to exploring this possibility of this approach, however, there is a
distinct possibility that site-specific studies utilizing recovery netting and appropriately
designed mortality studies maybe necessary. The top a-ad bottom elevation of the trashracks,
0

the width of the trashracks,, or the clear spacing for all of the trasbracks should be described.
Also, we need to know mean velocities in front of the intakes across the full range of
operating conditions. These are the minimum data needed to determine if fish impingement
and entrainment might be a problem at each development. The need for a more complete
mpmgomen t , entrainment and-turbine mortality study should be discussed withthe Services,
the state natural resource agencies, and other interested parties.
Justification. The cumulative loss of fish from entrainment and mortality at the 11
hydropower developments on the Catawba-Watereo Rivers is of concern. An estimate of
these losses at this project is necessary to determine the typo and extent of mitigation
(avoidance, minimization, compensation) necessary to off-set loss ofpublic trust resources.
11. Bypassed Reach
Explore and evaluate the feasibility of partial or total removal of the Mountain Island
Diversion Spillway, the Great Falls Diversion Dam and/or alternative methods to return
instream flows to the Great Falls.
Justification. The Mountain Island Diversion Spillway located downstream of Fishing Creek
Dam diverts the Catawba River into a parallel-canal and bypasses and dewaters 10,900 linear
feet of the Great Falls. The Great Falls Spillway bypasses 3,100 linear feet of river. The
Great Falls b3"s consists of bedrock, boulders and rocky shoals that if re-watered would
provide extremely high quality riffle/shoal habitat for a multitude of species, including
spawning habitat for anadromous species. Restoring instream flows to the dewatered Great
Falls for fish and invertebrate habitat and passage is a management objective ofthe Services.
12. Instream Flow Studies
The Services are concerned about the effects of the project operation on downstream flows in
terms of water quantity (timing and delivery) and water quality (dissolved oxygen, pH,
temperature, nutrients, suspended solids). We recommend a comprehensive instream flow
study of all riverine reaches downstream of the proj ect=s developments. The study should
utilize standard methods including instrearn flow incremental m��aio_ fogy, - eso TMSIM,
and Indicators of Hydrologic alteration (IHA), to evaluate the project effects on aquatic and
riparian communities- The Services are anxious to participate in an interagency team to
determine detailed study plans which consider target species and/or habitat guilds, habitat
suitability indices, location of study reaches and placement oftrmsects. We further request a
detailed study of how water withdrawals, discharges, and non-project uses of project lands
and waters affect instream flows, project operation, and fish and wildlife habitats.
The Services recommend a detailed study using MesoHABSIM (Pm-asiewicz 2001). The design
proposed here builds upon the Instrealn Flow Incremental Methodology but is focused on the
need for managing large-scale habitats and river systems like the Catawba-Wateree. It modifies
9

the data acquisition technique and analytical resolution of standard approaches, changingthe scale
of physical parameters and biological response assessment from;micro - to meso- scale. in terms
of technological process, a highly detailed mierohabitat survey of a few, short sampling sites is
replaced by mesohabitat mapping of whole -river sections. As with more traditional stream habitat
models, the variation -in the spatial distribution and amount of mesohabitats can provide key
information on habitat quality changes that correspond to changes in flow, channel, morphology,
and potential stream enhancement measures. This methodology should provide a basis for
quantifying habitat and simulating potential habitat changes with project operations. Other
investigations (e.g., Freeman et al. 2000), used microscale measurements, identified the central
role of shallow -water habitat in supporting stream fishes and explained responses of communities
to river regulation. Fish - habitat data at the mesoscale is relevant for river management, impact
assessment, and fish conservation. The results of analyzing microscale data are most easily
presented and used at the mesoscale.
Indicators of Hydrologic Alteration (1HA) should be used to describe the operational
effects of the project on riverine flows. We expect to utilize IHA analyses to evaluate the
effects of project operation on aquatic communities and their habitat. We also expect to
identify potential protection, enhancement, and mitigative measures to benefit fish and
wildlife resources in the affected reaches.
Freeman, M. C., Z. I-. Bowen, KID. Bovee, and E R. Irwin. 2000. Tlow and habitat effects- on
juvenile fish abundance in natural and altered flow regimes. Ecological Applications
11c179B190.
Parasiewicz, Piotr. 2001. MesoHABSBC a concept for application of instream flow models in reiver
restoratioibn planning. Fisheries 26(9)6 -13.
Richter, B. D., J. V. Baumgartner, R. Wigington, and D. P. Braun. 1997. How much water does a river
need? Freshwater Biology 37:231 -249.
Stalnaker, C. 1995. The instream flow incremental methodology: a primer for TIM. National
Ecology Research Centre, Internal Publication. U.S. Department of the Interior, National
Biolo i -al -gervicv,—F-art- C— oilins, Colorado.
13. Floodplain Inundation Evaluation
Assess flows needed for incremental levels of inundation of the Wateree River floodplain.
Evaluation should be conducted using the steps outlined in the section on the Floodplain
Inundation Method in Instream Flows for Riverine Resource Stewardship (2002). This
model consists of the following sequential steps:
1. Determine representative floodplain cross - sectional elevations through (a) the Federal
Emergency Management Agency (FEMA) and/or the U.S. Army Corps of Engineers
(USACOE) flood risk reaps; (b) topographic maps; (c) on -site surveys, including aerial

photogrammetric techniques;
2. Determine cross-section/stage-discharge relation by (a) measuring and surveying, (b) gage
calibration -rating table, or (c) gage records;
3. Determine wetted perimeter versus discharge, relation and inflection points for floodplain
4. Tabulate phenology and inundation needs for floodplain and riparian vegetation and
timing of floodplain-dependent life stages of fishes and other floodplain-dependent fauna;
5. Determine historical, unmodified hydrological timing, and magnitude of high flows;;
6. Evaluate surface connectivity between main channel and off -channel habitats such as
oxbow lakes through review of information obtained in steps I and 2 above;
7. Evaluate timing and duration needed to address biological needs tabulated in step 4 and
historical hydrology, step 5;
S. Develop flow recommendation or compare alternatives based on review of information
from steps5 to7.
Justification. Floodplain connectivity is an important ecological function within a river
system. Floodplain inundation contributes nutrients and woody debris to the system,
provides water cleansing functions, and creates a specialized habitat for floodplain
spawners. Reconnection of the river with its floodplain will contribute to a more fully
functional ecosystem. The study is needed to obtain the information necessary to evaluate
the positive benefits changes in flow patterns may make.
14. Mussel Surveys
Survey the tailwaters of each project development for freshwater mussels to document the
distribution, relative abundance, and reproductive success, as well as significant tributaries
which are isolated by the project and its operation. Additional, targeted surveys should
determine the presence/absence of federally listed mussels and federal species of concern.
Justification. Populations of eight species offreshwater mussel have been documented in the
Catawba River. Additional mussel species have been documented in tributaries. The
Catawba-Wateree reservoirs impound dozens ofmiles ofmainstera riverine habitat, isolating
populations of freshwater mussels and other nongame species in ion
these reservoirs are close enough to one another to affect much riverine habitat between
dams, limiting the recovery gradient in mussel populations in the tailwaters.
15. Robust Redhorse Surveys
The Robust redhorse and ACarolina- redhorse are rare sucker species that may occur
downstream and/or within the project. These species have been recently (re)discovered
through intentional sampling efforts in adjacent basins. Similar directed sampling efforts are
needed in suitable habitats for these species in the prej ect reservoirs and large tributaries. A
management plan will need to be prepared if these species are found in or -upstream of the
9

project. The applicant should intensively conduct electrofishing surveys for the imperiled
robust redhorse and ACarolina=— redhorse in identified reaches during the spring spawning
period and gill net for juveniles and/or adults during the fall months to determine the
presence/absence of the species within the project.
Electrofishing should be conducted during daylight hours over gravel bars and shoals when
water temperatures -range from 18-24E C. The target clectrofishing field should be 30-60
pulses per second with the voltage regulated to achieve an electrical output of 3-5 amperes.
Justification. The robust redhorse sucker (Moxostoma robustum) once thought extinct was
re-discovered in 1991 in the Oconee River, Georgia. Adults and juveniles have recently
been collected in the adjacent Yadkin-Pee Dee River drainage basin: The historic range of
the robust redhorse included Atlantic Slope drainages from the Pee Dee River in North
Carolina to the Altamaha River in Georgia. The Catawba-Wateree basin has never been
adequately surveyed for the presence of the robust redhorse. The robust redhorse is
considered imperiled and is a Federal Species of Concern. intensive surveys to determine its
presence or absence will aid the Services in determining appropriate flow recommendations
for specific reaches and habitat restoration and/or enhancement measures. The Service will
also use information from these studies to determine need for and prescriptions of fishways,
as well as potential protective status under the Endangered Species Act.
ka

11

12

Carolina heelsplitter (Lasmigona decoratal. There are records of the Carolina heelsplitter
from the Catawba River in the vicinity of the project. A targeted survey should be conducted
for the Carolina heelsplitter to include selected tributaries to the Catawba River within and
adjacent to the project boundary. The Service, along with Duke Power, Enbix, and others
performed- areconnaissance4evel-surve,y on October 26, 2001 of alimited arekimm.edi.ately
below the Lake Wylie dam along the night bank (Catawba River, right channel thread at
Fewell Island, immediately below Lake Wylie dam. 35.0167N, 81.0037W). The following
were located:
Strop.&Ys undulates - creeper
Effpgo complwaw - eastern elliptio
RUpdopmduculangustata - Atlantic spikc/Carohna lance
Pyg8nodon caLmchq - eastern floater
Utterbackfa imbecillis - paper pondshell
Villam deJambis - eastern crcekshe.11
Corbicula flumi7w - Asiatic clam
At the 1-77 bridge Catawba River (main channel, and upstream 300 yards;. 34.9876N,
80.9854W) we located:
Elliptio complanata - eastern elliptio
Elliptioproductalangustata - Atlantic spike/Carolina lance
At Landsford Canal State Park (34.8211N, 80.8823W), thewaterwas too turbid, and though
we mostly looked fbrmiddeu no native mussels found, only Corbicula fluminea (Asiatic
clam). There was an abundance of the non-native Corbicula at all sites, unfortunately. We
did not adequately survey for the presence,/absence of the Carobnaheelsplitter in the area of
affect .of the project. At the time of the survey, we notified Duke Power and Entrix staff that
there was a fairly diverse mussel assemblage at the site just below the Wylie powerhouse,
and that this site, along with other reaches, bears further looking. s sunflower does .
Schweinitz=s sunflower (Helianthusschweinitzii). TheSchweinitz- occur
within the area of affect of the Project, including within the project boundary. Additional
surveys should be conducted for this species, so that species protection plans may be
developed for all occurrences at the project.
Georgia aster (Astergeorgianus). The Georgia aster is a candidate species, and it does occur
-wilhm-the -mea-ef-d-feet-of-the-action—T-her-efore,-w-e-xcec-ommend-sh�dies to include
information about this species, and how it maybe affected by the continued operation ofthe
project, and any modifications made to the project operation of facilities during the next
license. We expect that FERC will need this information to complete a conference with the
Service for this species. We expect to use this information to determine the protective needs
of the species pursuant to the Endangered Species Act.
Robust Redhorse (Moxostoma robustum) and ACarolin=- RedhorsD (Moxostoma spl).
Although DeWitt (1998) used a variety of sampling gear and documented a significant
diversity of fishes from the Catawba River downstream of Lake Wylie, the methodologies
employed were not adequate to detect the robust redhorse or Carolina rodhorse, large mobile
fishes. We are quite concerned about how the project operation and project works affect
these rare fishes. We expect to use this information to determine mitigative measures for
1%

LU
operation of the project as well as for determining the protective needs of the species
pursuant to the Endangered Species Act.
Shortnosesturge (Acipenserhrevirostmm). Intensive surveys to determine its presence or
absence will aid the Service in determining appropriate flow recommendations for specific
reaches-and habitat-restoration and/or - enhancement measures. The -Service -will -also- use
information from these studies to determine need for and prescriptions of fish ways.
Rocky shoals spider lily (Hymenocalliscoronaria). We recommend targeted surveys for this
species, to identify the range and habitats, including collection of data which may describe
how the project operation affects the species. We expect to use this information to determine
mitigative measures for operation of the project, as well as for determining the protective
needs of the species pursuant to the Endangered Species Act.
We recommend that surveys be conducted by comparing the habitat requirements for these
species with available habitat types within the action area of the project. AAction area=— is
defined at 50 CFR a 402.02 as A ... all areas to be affected directly or indirectly by the Federal
action and not merely the immediate area involved in the action.—= Field surveys for the
species should be performed if habitat requirements overlap with that available at the prej ect
site. Surveys for protected plant species must be conducted by a qualified biologist during
the flowering or fruiting period(s) of the species. We welcome the opportunity to assist with
the design of studies, sampling schemes, methodology, and target areas for the above species,
as well as analysis of the Aeffects fo the action,=— (as defined by 50 CFR 3 402.02) on any
listed species including consideration of direct, indirect, and cumulative effects.
We also recommend -mitacting the -S .C-. Department of Natural Resa=69-(SCDNR);-Data
Manager, Wildlife Diversity Section, Columbia, S.C. 29202 concerning known populations
of federal and/or state endangered or threatened species, and other sensitive species'in the
project area. Additional habitat information may also be available from SCDNR. NOAA
Fisheries endangered species office in St. Petersburg, Florida should be contacted relative to
shortnose sturgeon which may occur in the action area.
Migratory Birds *
Evaluate the effects of the project on migratory bird use of the Catawba Wateree riverine
and riparian ecosystems. Surveys of migratory birds and their habitats should begin in the
Fall of 2003 to provide baseline information on populations.
Justification. 'MijuatorvbiTds,)particularlyneotroDicaI migrants, utilize the Catawba-Wateree
system formintering habitat. These species have potentially been adversely affected by the
project by the decrease in available wetlands and floodplain habitat, loss of foraging habitat,
and alteration ofripaiian habitat. Information on population estimates and habitat utilization
are needed to determine potential enhancement measures.
16. Project Operations
Evaluate the effects of project operations on ecological processes, including geomorphic
functions, sediment regime, -and woody debris cycling in riverine reaches. This study should
assess the effects of project operations and project works on distribution and flow of
sediments, woody debris, and nutrients through the project.
Justification. Project developments (dams) impede the natural flow of sediment, woody
debris, and nutrients through the river system. The alteration of natural geomorphic
14

processes adversely affects downstream aquatic flora and fauna by limiting the elements
necessary for species to adequately complete their life cycles. An evaluation of these effects
will aid in the development of restoration, enhancement and mitigation measures.
11. Potential Mitigation Options
the relicensing..of.the.-Catawba-7W.4t!orce,, project asjustb gun too early to
Whi P e b -q- it
begin investigating off-site and non-traditional mitigation opportunities. Small, non-
functional dams within the basin that could be removed should be identified. Elimination of
these barriers would help to restore rivenine ecologyto these systems. Another possibility is
conducting stream and wetland-restoration projects or purchasing riparian easements in the
basin- Conservation efforts, such as the acquisition, protection, and establishment of wide
forested riparian buffers, should focus on tributaries identified as supporting freshwater
mussels and other rare species, for tributaries identified as priority aquatic habitats. The
applicant should identify areas that could be protected or enhanced for migratorybirds. The
Services are also concerned about the adequate provision of opportunities for fish- and
wildlife-based recreation, such as bird watching, fishing and hunting. There may be
opportunities for Duke Power to enhance the project area for these activities. Werequesta
map of other er Duke Power and other Duke Energy properties to assess the juxtaposition
Of these lands to important wildlife areas.
If you have any questions about these study recommendations, or need additional information,
please contact Mr. Mark A. Cantrell, at [phone] (ext. 227), or Ms. Amanda Hill, at (843)
727-4707 (ext. 24)-of the-U.S. -Fiish and. Wildlife Service and Mr. Prescott Brownell,at-(043)
762-8591 of NO AA Fisheries.
Sincerely,
Roger L. Banks
Field Supervisor
U.S. Fish and Wildlife Service
David H. Rackley
Chief, Charleston Area Office
Habitat Conservation Division
NOAA Fisheries
15

AttachmentA. ENDANGERED, THREATENED, AND CANDIDATE SPECIES AND
FEDERAL SPECIES OF CONCERN, IN THE VICINITY OF CATAWBA-WATEREE
PROJECT, I N N ORTH CAROLINA AND SOUTH CAROLINA
This is,a listing.of federally listed.and proposed-en4angered, threatened, and cand.idate species
and Federal species of concern (for a complete list of rare species in each state,. please contact
the North Carolina Natural Heritage Program or the South Carolina Natural Heritage Program).
The information in this list is compiled from a variety of sources, including field surveys, .
museums and herbaria, literature, and personal communications. Our database is dynamic, with
new records being added and old records being revised as new information is received. Please
note that this list cannot be considered a definitive record of listed species and Federal species
of concern, and it should not be considered a substitute for field surveys.
This list should be used only as a guideline, not as the final authority. The list includes known
occurrences and areas where the species has a high possibility of occurring. Records are
updated regularly and subsequent versions may be different from the following:•
COMMON NAME SCIENTIFIC NAME .�STATUS
"Carolina" meatom Noturus farlosus population 2 FSC
A liverwort
Cephaloziella obtusilobula
FSC*
A liverwort
Plagiochila sullivariffl var. spinigera
FSG
A liverwort
Plaglochila suffivantY var. suftantfi
FSC
A liverwort
Porafla wataugensis
FSC*1
A.11-eghany woodrat
INeotoma magister
FSC-1
d_
American -alligator
Alligator mississipplahsis
-T(S/A).
American kestrel
Atlantic pigtoe
Falco sparverius
Fusconala mason!
FSC
Auriculate false foxglove
romanthere auriculata
FSC
Bachman's sparrow
Aimophia aestivalis
FSC
Bald eagle
Hallaeetus leucocephalus
Threatened
Benn eft's Mill Cave waters later
Gaecidotea carofinensis
FSC
Bent averts
Geum genloulatum
FSC
Biltmore greenbriar
Smilax biltmoreana
Black-spored quillwort
Bog turtle
Isoates melanospora
lClemmys muhleribergil
_FSC
FSC
T(SIA)l
Buttercup phacelia Phacefie coville! FSC
Butternut Juglans cinerea SC
Carolina bogmint Macbridea carofiniana FSC
Carolina creekshell Villosa vaughaniana FSC
Carolina darter iEtheostome collis collis FSC
"Carolina" redhorse mexostoma SP1 FSC
Carolina pygmy sunfish Elassoma boehlkei FSC
Carolina saxifrage Saxifraga carofiniana, FSC
Catawba crayfish oit-racod Dactyloctythere isabelae FSC
Cerulean warbler Dendrolce cerulea FSC
lCreeD!na St. John's Wort Wvneilcum adoressum

Diana fritillary butterfly
Speyeria diana
FSC
_
Georgia aster
Aster georgia,nus
Candidate
Dwarf - flowered heartleaf
Hexaslyfis naniflora
Threatened
Edmund's snaketail dragonfly
Ophlogomphus edmundo
FSC
Fraser fir
Abies frasari
FSC
Georgia aster
Aster g6drg-lahus
FSC
Gray's lily
LIU= grayi
FSC
Heller's blazing star__
Liatris hellari
'Threatened
Heller's trefoil
Lotus heller!
FSC
Henslow's sparrow
Ammodramus henslowl!
FSC
Little amphlanthus
Amphianthus pusillus
Threatened-.-
Loggerhead strike
Lanius, ludovicianus
FSC
Margarita River skimmer
Macromia-margarita
FSC*
Michaux's sumac
Rhus michauxii
Endangered*
Mountain bittercress
Cardamine clematitis
FSC -
Mountain golden heather,
Hudsonla montana
Critical Habitat
Northern oconee7bells
Shortia galacifolia var. brevistyla
FSC
Olive-sided flycatcher
Contopus borealis
FSC
One-flower stitchwort
Paintedbunting
Inuartia unifibra
Passerina chis d . n . s
FSC
FSC
Pee Dee crayfish ostracod
Dactylocythiare peedeansfs
FSC*
Pinewoods shiner
PondspiGe
--
Lythrurus matudbus
Litsea a;stivarji—s
FSC
FSC
Prairie birdsfoot- trefoil
Pygmy snaketall dragonfly
Lotus p&rshkinusVar. hellefj
Ophiog6rnphus howei
FSC
Rafinesque's big-eared bat
Corynorhinus rafinesquii
FSC
Red-cockaded woodpecker
Picoldes borealis
Endangered
Riparian vervain
Verbena tiparia
FSC*
Roan sedge
Carex roanenis
FSC
Robust redhorse
Moxostoma robustum
FSC
Rocky Shoals spider-lily
Hymenocaffis coronaria
FSC
Sandhills milkvetch
Astragalus michauxii
FSC
Savanna lilliput
Toxo1asma pullus
FSC
Schweinitfs sunflower
Helianthus schweinftzii
Endangered
Small whorled pogonia
Isotria medeololdes,
Threatened
Smooth--c-on—efl5-w—er
a inacea-iaevigata
Endangered
Southern Appalachian black-capped
Poecile atdcapillus practicus
FSC
chickadee
Southern Appalachian red crossbill
Loxia curvirostra
FSC
Southern Appalachian saw-whet owl
Aegolius acadicus
FSC
Southern Appalachian woodrat
Neotoma floildana heematore/a
FSC*
Southern Appalachian yellow-bellied
Sphyrapicus vailus appalaciensis
FSC
sapsucker
Southern dusky salamander
Desmognathus auriculatus
FSC
Southern myotis
Myoffs austroriparlds
FSC
Spreading avens
Geum radiatum
Endangered
Spruce-fir moss spider
Microhexura montivaga
Endangered
Sun-facing coneflower
Rudbeckia helippsidis
FSC
Swainson's warbler
Umnothlypis swainsonfi
FSC
- - - -- ----Sweet-pinesap-----------Monotropsis-odorata----.--
FSC*

Tall larkspur
Delphinium exaltatum FSC*
Virginia least trillium
Trillium pusillum var. virginianum FSC
Virginia quillwort
lsoetes virginica FSC
White false asphodel
Tofleldia.glabra FSC
White -wicky
Kalmia cuneata FSC
Wire leaved dropseed Sporobolus teretifolius - FSC
Yellow iampmussel Lampsills cariosa FSC
Yellow lance
Elliptio /anceolata FSC
Y:
Status
Definition
Endangered
A taxon "in danger of extinction throughout all or a significant portion-of its range."
Threatened
A taxon `,`likely to become endangered within the foreseeable future throughout all or a
significant portion of its range."
Proposed
A taxon proposed for official listing as endangered or threatened.
C1
A taxon under consideration for official listing for which there is sufficient information
to. support listing.
FSC
A Federal species of concern - -a species that may or may not be listed in the future
(formerly C2 . candidate species or species under consideration for listing for which there .
is insufficient information to support listing).
T(S /A)
Threatened due to similarity of appearance (e.g., American alligator ) - -a species that is
threatened due to similarity of appearance with other rare species and is listed for its
protection. These species are not biologically endangered or ± hreatened and are not
subject to Section 7 consultation.
EXP
A =on that is listed as experimental (either essential or nonessential). Experimental,
nonessential endangered species (e.g., red wolf) are treated as threatened on public land,
for consultation purposes, and as species proposed for listing on private land.
Species with 1, 2, 3, or 4 asterisks behind them indicate historic, obscure, or incidental records.
*Historic record - the species was last observed in the county more than 50 years ago,
* *Obscure record - the date and/or location of observation is uncertain.
* * *Incidental/nugrant record - the species was observed outside of its normal range or habitat.
* * ** Historic record. - obscure and incidental record.
Contact- NOAA-F-isheries . or moxe�nfofonnatio is s ecies.

PDuke
e>>enrer®
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November 17, 2004
Ms. Renee Gledhill-Earley
North Carolina Department of Cultural Resources
4617 Mail Service Center
Raleigh, NC 27699-4617
•
Subject: Catawba-Wateree, Hydroelectric Project Relicensing
FERC No. 2232
Cultural 0I DRAFT Study Report
Dear Ms. Gledhill-Earley:
526 South Church Sirect
P0. Box 1006
CharlOtLC, NC 28201-1006
Mail Code EC12Y
Enclosed please Find 2 copies of DRAFT report tilled `Cultural Resources Surl,eJ.'Jor the
ataii,ba-ff,"ateree Hydroelectric Relicensing Project, Alexander, Burke, Cataii,ba, Gaston,
Iredell, Lincoln, McDoii,ell and Ilecklenburgr Counties, ,Vorth Carolina, " 'rills study was
conducted by TRC in accordance with the Catawba-Wateree Relicensing Project Study Plan
Cultural 01.
Please provide any comments you have on the report by December 22, 2004.
Please do not hesitate to contact me at 980.373.4192 orjrliuf*f((�,,,duke-eiiergy.com should You
have any questions regarding this report or the relicensint
effort in general. We appreciate Your
continued involvement in the relicensing effort.
Sincerely.
Jen6l ter R. Huff FJ
Hydro Licensinu Compliance
FInclosure (2 copies)
cc sv/o enclosure: Delores Hall. NCDCR
E.M. Oakley

North Carolina Department of Cultural Resources
State Historic Preservation Office
Peter B. Sandbeck, Administrator
Michael F. Easley, Governor office of Archives and History
Lisbeth C. Evans, secretary Division of Historical Resources
Jeffrey J. crow, Deputy secretary David Brook, Director
April 16, 2008
Jennifer R. Huff
Sr. Environmental Resource Manager
Duke Energy Carolinas, LLC
ECI2YJPO .Pox 1006
Charlotte, NC 28201 -1006
Re: Acceptability of HPMP for Catawba - Wateree Hydroelectric Project (FERC # 2232),
Multi County, ER-03-3059
Dear Ms. Huff:
Thank you for your letter of April 7, 2008, asking that we formally respond to the acceptability of the Historic
Properties Management Plan (HPMP) for the above referenced undertaking. We apologize that we did not
respond to the previous submittals. As noted in your letter, we thought that our signature on the relicensing
agreement addressed this matter.
For purposes of Section 106 of the National Historic Preservation Act and, as requested by the Federal Energy
Regulatory Commission, the North Carolina State Historic Preservation Officer accepts the final HPMP for
the Catawba - Wateree Hydroelectric Project.
Thank you for your cooperation and consideration. If you have questions concerning the above comment,
contact Renee Gledhill- Earley, environmental review coordinator, at 919 - 807 -6579. In all future
communication concerning this project, please cite the above referenced tracking number.
Location: 109 Ease Jones Street, Raleigh NC 27601 Maiiiing Address. 4617 Mail Serme Center, Raleigh NC 27699 -4617 Telephone /Fax: [phone] -6599
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