20030179 Ver 6_Monitoring Plan_20100302

PhDuhe I Ener9 e
Carolinas
February 15, 2010
Mr. John Dorney
NC Division of Water Quality
1650 Mail Service Center
Raleigh, NC 27699-1650
Subject: Dillsboro Hydroelectric Project (FERC No. 2602)
Modification request to fish monitoring
Dear Mr. Dorney:
o3-ot'l q VeK U
HYDRO STRATEGY & LICENSING
Duke Energy Csrolinim UC
EC12YI526 South Church Sheet
Charlotte, NC 28202-1802
Ma ft Address:
EC12Y/P.O. Box 1006
Charlotte, NC 28201-1006
d - I?j
MAR 2 2010
WETLANDS AND $TORh11MATO MUNCM
On November 21, 2007, the North Carolina Division of Water Quality (NCDWQ) issued to
Duke Energy Carolinas, LLC (Duke) a 401 Water Quality Certification with Additional
Conditions (Certification) that was subsequently modified on January 14, 2010. This
Certification required Duke to collect at least two fish samples (at different seasons) from the
Tuckasegee River before removal of the Dillsboro Dam and then complete three years of post-
dam removal fishery sampling. The methods proposed by Duke for this sampling were
developed in cooperation with the NCDWQ staff and presented to the NCDWQ in July 2008
(Water Quality and Environmental Monitoring Programs).
Pre-dam removal fish samples were collected in 2008 using electrofishing equipment along 200-
m transects on the left and right ascending banks at each of four sampling locations. Due to the
abundance of fish in the sampled locations, this sampling distance produced numbers of
collected fish that were approaching more than could be kept alive using ordinary means. After
exploring various ways to enhance the survival of the collected fish, Duke feels that reducing the
length of the sampling locations is the best way to maximize the survival of collected fish while
providing robust data needed to evaluate the impacts of dam removal on fish populations in the
Tuckasegee River. Therefore, I am requesting that you approve an amendment to the fishery
monitoring methods that were previously submitted. Specifically, Duke would like to reduce the
length of our electrofishing transects from 200 m to 100 in for the upcoming post-dam removal
sampling period (2010-2013). If you have questions or concerns regarding this request, please
do not hesitate to contact me at 704/382-0805.
Sincerely,
Hugh Barwick
Senior Environmental Resources Manager
Mr. John Dorney
Page 2
cc: Mark Cantrell, USFWS
Chris Goudreau, NCWRC
t'a?E, wy.
Carolinas
July 8, 2008
Mr. John Dorney
NC Department of Environment and Natural Resources
Division of Water Quality
1650 Mail Service Center
Raleigh, NC 27699-1650
Subject: Dillsboro Hydroelectric Project (FERC No. 2602)
Water Quality and Environmental Monitoring Programs
Dear Mr. Dorney-
HYDRO STRATEGY & LfCEMSING
Dub EMN Cmbak UC
EC12YI526 South Church Shat
Chwtfts, NC 28202-1802
EC12Y/P.O. Box 1008
Charlotte, NC 28201-1000
ag (r-?, [E W/
ko L
MAR 2 2010
DENR-WATER QUALITY
WETLANDS AND STMT "'b"? BRA
Attached is a copy of the Water Quality and Environmental Monitoring Programs that Duke
developed for protecting the riparian and aquatic resources of the Tuckasegee River during the
removal of the Dillsboro Dam and Powerhouse. This report is being provided to you to indicate
Duke's compliance with the Division of Water Quality's (DWQ) 401 Water Quality Certification
with Additional Comments (November 21, 2007) and the Federal Energy Regulatory
Commission's Order Accepting Surrender and Dismissing Application for Subsequent License
(July 19, 2007), as amended by the Order on Reficensing and Clarification (April 22, 2008).
As you may recall, Hugh Barwick of my staff provided DWQ with an opportunity to review and
comment on several items that are included in this report. However, you declined to comment
on this information due to ongoing litigation associated with the Dillsboro Project. At that time,
you suggested that if maintaining the dam removal schedule was of importance to Duke (which it
is), that Duke should proceed without formal input from the DWQ. Duke did develop and has
implemented these monitoring programs based on informal input from members of your staff
(Bryn Tracy and Patricia MacPherson) and on the specifics outlined in the 401 If you have
questions regarding any of these programs, please contact Hugh at 704.382.0805 or
[e-mail]. We look forward to working more closely with you on this project
once all legal concerns are resolved.
Sincerely,
Jeffrey G. Lineberger, PE
Director, Hydro Strategy do Licensing
Enclosure: Report
cc w/enclosure: Coleen Sullins, DWQ
Mark Cantrell, USFWS
Mr. John Domey
Page 2
Chris Goudreau, NCWRC
Scott Fletcher, DTA
Garry Rice, Duke
Hugh Barwick, Duke Energy
bcc: Filenet
Dillsboro Dam and Powerhouse Removal Project
(FERC #2602)
Water Quality and Environmental Monitoring Programs
?9@00%qgp
MAR 2, 2010
R . WATER QUALITY
AND STOR,4IWATER BRANCH
Prepared for: Prepared by:
DUKE ENERGY DEVINE TARBELL &
ASSOCIATES, INC.
WDuke D
`T'
.A
(Energy.
Devine Tarbell & Associates, Inc.
?FR4&ciie. i RetWbR SpccbWo
July 2008
1.
Duke Energy Carolinas, LLC Dillsboro Dam Removal
Water Quality and Environmental Monitoring Programs
TABLE OF CONTENTS
1.0 Introduction .............................................................................................................. 3
1.1 Background ..................................................................................................................... 3
1.2 Monitoring Program .....................
1.3 Schedule .......................................................................................................................... 5
2.0 Pre-Removal Monitoring ......................................................................................... 5
2.1 Water Quantity and Quality .............................................................................................6
2.2 Aquatic Resources ........................................................................................................... 6
2.2.1 Fisheries Monitoring .................................................................................... 7
2.2.2 Maeroinvertebrate Monitoring ...................................................................... 8
2.3 Riparian Habitat ............................................................................................................... 8
2.4 Sediment ..........................................................................................................................9
2.4.1 Pre-Removal Dredging ................................................................................ ..9
2.5 Reporting Requirements ................................................................................................ .. 9
3.0 Dam and Powerhouse Removal Plan ................................................................... 10
4.0 Dam Removal Monitoring .....................................................................................10
4.1 Water Quantity and Quality ...........................................................................................10
4.2 Sediment ........................................................................................................................11
4.3 Fish Stranding Monitoring ............................................................................................12
4.4 On-Site Consultation .....................................................................................................12
5.0 Post-Dam Removal Monitoring ............................................................................12
5.1 Water Quality ................................................................................................................13
5.2 Sediment ........................................................................................................................13
5.3 Revegetation ..................................................................................................................14
5.4 Aquatic Resources .........................................................................................................15
5.4.1 Fisheries Monitoring ...................................................................................15
5.4.2 Macroinvertebrate Monitoring .......................................... ................15
5.5 Riparian Habitat .............................................................................................................15
5.6 Exotics ...........................................................................................................................15
5.7 Metal (Nickel) Testing ..................................................................................................15
6.0 Literature Cited .....................................................................................................17
APPENDIX A-MAP OF PROJECT MONITORING LOCATIONS
2

Duke Energy Carolinas, LLC Dillaboro Dam Removal
Water Quality and Environmental Monitoring Programs
DILLSBORO DAM AND POWERHOUSE REMOVAL
WATER QUALTIY AND ENVIRONMENTAL MONITORING PROGRAMS
Duke Energy Carolinas, LLC's (Duke) Dillsboro Hydroelectric Project is a Federal Energy
Regulatory Commission (FERC) licensed project (FERC No. 2602) located adjacent to the Town
of Dillsboro in southwestern North Carolina (Jackson County) on the Tuckasegee River. The
Dillsboro Dam is located at River Mile (RM) 31.6 and creates a small impoundment (Dillsboro
Pond) that is about 15 acres in area and about 0.8 miles long at a full pond elevation of 1,972 feet
above mean sea level (MSL). Duke's East Fork (FERC No. 2698) and West Fork (FERC No.
2686) Tuckasegee River projects regulate flow into Dillsboro Pond. Duke used the Dillsboro
Project to generate electricity for retail customers in the region until the powerhouse was flooded
in 2004. Since that time, the two generating units have remained inoperable.
1.0 Introduction
The Dillsboro Dam is a concrete masonry structure about 310-feet long and 12-feet high. Major
components of the Dillsboro Dam are listed below, beginning at the left abutment facing
downstream. All elevations are referenced in U. S. Geological Survey datum and are expressed
in feet above MSL. Main components of the dam include:
¦ A concrete, non-overflowing section with crest elevation 1978.2 ft
¦ An uncontrolled 14-foot-wide spillway section with crest elevation 1972.0 ft
¦ A 20-foot-wide spillway section with two 6-foot-wide spill gates having a gate sill
elevation of 1961.0 ft
• A 197-foot-wide uncontrolled spillway with crest elevation 1972.0 ft
• A 64.5-foot wide powerhouse composed of a steel and wood superstructure, a concrete
substructure, and an 80-foot-wide intake section
¦ A concrete, non-overflowing section with crest elevation 1980.0 ft.
1.1 Background
The existing license for the Project expired July 31, 2005, and the process of obtaining a
subsequent license officially began in March 2000 with Duke's release of the First Stage
Consultation Document and the filing of the Notice of Intent to Relicense the Project. The
Tuckasegee Cooperative Stakeholder Team (TCST) and the Nantahala Cooperative Stakeholder
Team (NCST) settlement agreements, which were signed by most of the cooperative relicensing

3

Duke Energy Carolinas, LLC Dilbboro Dam Removal
Water Quality and Environmental Monitoring Programs
process participants in late October 2003, included the Multi-Project Resource Enhancement
Measure that called for removal of Dillsboro Dam and potentially the Powerhouse. As stated in
Paragraph 6.3 of each agreement, "...the Parties acknowledge that Duke worked with the
USFWS (U. S. Fish and Wildlife Service), NCDWR (N. C. Division of Water Resources),
NCDWQ (N. C. Division of Water Quality), NCWRC (N. C. Wildlife Resources Commission),
the NCSHPO (N. C. State Historic Preservation Office), and the EBCI (Eastern Band of
Cherokee Indians) and completed the necessary environmental, cultural resource, and engineering
assessments regarding the removal of Dillsboro Dam and potentially the Dillsboro Powerhouse.
These assessments evaluated the potential effects of dam removal on aquatic species; determined
the extent of any cultural resources impacts, and considered the options of removing the
powerhouse." A complete analysis of anticipated environmental impacts resulting from dam
removal can be found in the Environmental Assessment and Biological Assessment: Future of
Dillsboro Dam Jackson County, North Carolina prepared by Duke.
A License Surrender Application for the Project was submitted by Duke to the FERC in May
2004. This application included the rationale for surrendering the Project, a Project
decommissioning plan, a consultation record, and the above-mentioned environmental
assessment. In May 2005, the NCDWQ issued a 401 Water Quality Certification for removal of
the Project and in November 2007 issued approval of the 401 Water Quality Certification with
Additional Conditions. Additionally, the FERC issued the Draft Environmental Assessment and
Final Environmental Assessment in May and July 2006, respectively.
The removal of the Dillsboro Dam and Powerhouse will provide an important resource
enhancement initiative that will mitigate for the various impacts of other Duke projects, as
described in the TCST and NCST agreements. In part, the removal of Dillsboro Dam would
provide compensation for fish passage for the first 20 years of the new license at all Duke hydro
projects in the Nantahala region and instream-flow relief in certain bypassed stream reaches
associated with the Nantahala, East Fork, and West Fork projects. Additional information
concerning the plan and the processes associated with the removal of Dillsboro Dam and
Powerhouse can be found in the License Surrender Application.
1.2 Monitoring Program
The environmental monitoring programs herein are required by the NCDWQ through its 401
Water Quality Certification with Additional Comments (November 21, 2007) and by the FERC
4
Duke Energy Carolinas, LLC Dillsboro Dam Removal
_ Water Quality and Environmental Monitoring Programs
through its Order Accepting Surrender and Dismissing Application for Subsequent License (July
19, 2007), as amended by the Order On Rehearing and Clarification (April 22, 2008). These
programs are designed to protect the riparian and aquatic resources of the Tuckasegee River
during the demolition of the Dillsboro Dam and Powerhouse and were developed in consultation
with the following resource agencies and stakeholders: the NCWRC, the USFWS, the U. S.
Forest Service, the NCDWQ, the NCDWR, the NCSHPO, and the EBCI. Duke has and will
continue to meet with the pertinent agencies and other interested parties to identify any
unresolved resource or safety issues prior to dam removal. These meetings are to ensure the full
disclosure and discussion of relevant dam removal issues.
1.3 Schedule
The anticipated schedule associated with the Dillsboro Dam and Powerhouse removal includes a
three-phase environmental monitoring plan. The monitoring plan began in January 2008 (pre-
removal monitoring) and will end with the completion of post-removal monitoring (anticipated
not to extend beyond March 2012). Post-removal monitoring will occur over a two- to three-year
period as required by the NCDWQ and/or the FERC. Table 1 provides a summary for the
duration of the pre-removal, removal, and post-removal activities.
Table 1. Anticipated Environmental Monitoring Schedule
Task Start End Date 2008 2009
Date JFMAMJJASOND JFMAMJJASOND
Pre-Removal Jan 2008 Dec 2008
Phase
Monitoring
Removal Phase Jan 2009 Mar 2009
Monitoring
Post-Removal Mar 2009 2 to 3 years
Phase after dam
Monitoring removal is
complete
2.0 Pre-Removal Monitoring
In association with the preparation of the license application for this Project, a considerable
amount of information existed regarding the environmental resources within the Project area (see
Final Dillsboro License Application submitted to the FF.RC on July 22, 2003). This information
in addition to the data collections proposed for this Project will be used in assessing the physical
and biological changes associated with dam removal and will aid in establishing the pre-removal
baseline conditions with which the success of dam removal will be compared.
5
Duke Energy Carolinas, LLC Dillsboro Dam Removal
Water Quality and Environmental Monitoring Programs
2.1 Water Quantity and Quality
Conductivity, dissolved oxygen (DO), pH, temperature, total suspended solids (TSS), turbidity, as
well as the rate of flow will be measured at locations both upstream and downstream of the dam
removal site. These data will be collected as required during the pre-removal phase of the project
(Table 2). The water quality monitoring locations (Appendix A) were selected based on agency
consultations and previous study locations, and may be modified somewhat in the future based on
additional consultation, field access, and adjustments or changes in the dam removal process.
Conductivity, DO, pH, temperature, and turbidity will be collected in-situ, while TSS will be
analyzed by a NCDWQ certified laboratory. Mainstem Tuckasegee River flows will be recorded
at several nearby U. S. Geological Survey stream flow measuring gages, while tributary flows
near Dillsboro Dam will be measured manually during the water quality sampling events.
'fable 2. Pre-Removal Phase Monitoring
Monitoring Monitoring Monitoring Monitoring Period
Station Location Activity
M1 /Downstream RM 31.1 WQ, Photo - Monthly
M2 / Downstream Scott's Creek; WQ, Photo - Monthly
0.5 mile
upstream of
confluence
M3 / Downstream RM 31.5-31.6 WQ, Photo, - WQ, Photo: monthly
Habitat, Fish, -Habitat: Mar 2008
Macro, Pebble - Fish, Macro, Pebble Counts: immediate
Counts tailwater in Ma and October
T6 / Downstream RM 27.2-27.5 Fish, Macro, - Barker's Bridge area in May and October
Pebble counts
M5 / Upstream RM 32.9-33.8 WQ, Photo, - WQ, Photo: monthly
Fish, Macro, -Habitat: Mar 2008
Pebble Counts - Fish, Macro, Pebble Counts: upstream of
Dillsboro Pond in May and October
M7 / Upstream RM 33.6 WQ, Photo - Monthly
T1-T17 RM 12.3-32.7 Sediment, - Cross-sectional profiles, sediment samples,
Photo, Fish, Photos: Quarterly and after storm events
Macro (i.e., flow rate as measured from the nearest
gage)
- Fish, Macro: Dillsboro Pond (near T13) in
May and October
- ---w -F- ...... - will uc tuccn in all aic monuormg iocanons.
2.2 Aquatic Resources
Historic fisheries and macroinvertebrate data, along with data collected in 2008 within the Project
area and in the nearby upstream and downstream areas, will be used to establish baseline data for
6
Duke Energy Carolinas, LLC Dillsboro Dam Removal
Water Quality and Environmental Monitoring Programs
the proposed dam removal activities. Additional information from the license application will be
used as needed and may include the Instream Flow Incremental Methodology (IFIM) study data,
and information on rare, threatened, and endangered aquatic species within and adjacent to the
Project area.
2.2.1 Fisheries Monitoring
Fisheries monitoring locations (Table 2 and Appendix A) will include a riverine reach upstream
of the influence of the Dillsboro Pond (MS), the Dillsboro Pond (T13), the tailrace of Dillsboro
Dam (M3), and one location well downstream of the dam (T6). Fish community sampling will be
conducted along 200-m segments on the right and left ascending banks (RAB and LAB,
respectively) at each of the four sampling locations in May and October for one year prior to (and
three years subsequent to) dam removal. At all locations, fish will be sampled using pulsed DC
electrofishing techniques. Electrofishing settings will be adjusted to achieve maximum sampling
efficiency, while minimizing injury to the fish.
Sampling plans will be coordinated with Duke's Hydro Central to ensure that river flows are most
conducive to sampling efficiency, while ensuring sampling crew safety. In the impoundment and
riverine areas of suitable depth, boat electrofishing will be used. In shallower, wadeable areas, a
tote barge, backpack electrofisher or a combination of the two will be used. An attempt will be
made to maintain sampling gear consistency throughout the pre- and post-removal periods,
however, changes in instream conditions subsequent to dam removal may require changes in gear
type (e.g., boat electrofishing to tote barge or backpack electrofishing).
With the exception of a few specimens that will be preserved in formalin and returned to the
Duke Environmental Center for taxonomic identification, all netted fish will be identified,
measured (total length in nun), and returned alive to the river. Catch data will be tabulated as the
number of species and individuals per 200 m of shoreline. Fish communities at each of the four
locations will be evaluated for their aggregate pollution tolerance rating (i.e., their ability to
withstand pollution). Additionally, the trophic guilds of adults will be evaluated to assess the
effects of biotic interactions and energy supply. Water temperatures (°C) and DO concentrations
(mg/L) will be measured at each location with a calibrated thermistor and DO probe, respectively.
Water samples for specific conductance (µS/cm) will be collected at each shoreline segment,
refrigerated, and returned to the Duke Environmental Center, where conductance will be
measured with a calibrated Hydrolab Datasonde.
Duke Energy Carolinas, LLC Dillsboro Dam Removal
Water Quality and Environmental Monitoring Programs
2.2.2 Macroinvertebrate Monitoring
Macroinvertebrate collections will be conducted at the four locations described above for
fisheries monitoring and at the same time of year. The standard qualitative method as outlined in
the NCDENR's Standard Operating Procedures will be used to collect and process
macroinvertebrate samples. This method requires the use of a variety of nets to sample the major
habitats available. Discrete samples will include two kicknets, three sweep nets, three fine mesh
(for Chironomidae) samples, including a sand sample, one leaf pack, and one visual search of the
area. Due to the reservoir habitat in Dillsboro Pond, samples from this location will be collected
using Ponar grabs in place of the two kick net samples. Samples will be sorted in the field and
identified to the lowest practicable taxon in the laboratory.
For each location sampled, a bioclassification will be derived which gives equal consideration to
the number of Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa present and the biotic
index value of the sample. The biotic index value for a particular sample is a summary measure
of the tolerance values of organisms found in the sample, relative to their abundance. A score is
assigned to both the biotic index value and EPT value, and the mean of these two scores is used to
assign one of five bioclassifications, ranging from "Poor" to "Excellent." Bioclassifications will
be determined using mountain region criteria, and seasonal corrections will be made for both the
May and October collections. Water temperatures, DO concentrations, and conductivity will be
measured at each location as described in the fisheries monitoring.
Additionally, pebble counts will be performed at the same times and locations as the benthic
macroinvertebrate collections, except in the Dillsboro Pond where a large volume of sediment
presently covers the substrate. Pebble counts will utilize the method described by Wolman
(1954).
2.3 Riparian Habitat
Changes in riparian areas will be documented through use of photographic stations and vegetation
plots located throughout the existing pond. The overall quality and change in habitat will be
assessed at each survey transect with the use of a stream habitat evaluation index. The index will
be assessed within the pond before dam removal and the initial results will be used as baseline
data for the assessments following dam removal.
Duke Energy Carolinas, LLC Diilsboro Dam Removal
Water Quality and Environmental Monitoring Programs
2.4 Sediment
The Project has acted as a sediment sink since completion of the dam (Milone and MacBroom
2004). Currently, the reservoir is in a steady state and filled to near capacity with sediment. An
estimated 100,000 cubic yards of sediment is located upstream of the dam and consists of
particles that are generally less than 10 mm in size. Thickness of the deposits is estimated to be
up to 12 feet near the dam and decreases considerably upstream (i.e., 0.8 miles upstream of the
dam).
Seven sediment-monitoring cross-sections (Appendix A) have been established in the immediate
area of the Project (two immediately below the dam, four in the pond, and one above the pond).
Ten additional sediment monitoring cross-sections (Appendix A) have been established in the
downstream reach ending at the Slope Street Bridge in downtown Bryson City, North Carolina.
Pre-removal sediment monitoring began in 2008, will continue during dam removal, and will
continue for three years following dam removal. Pre-removal cross-sectional profiles will be
taken quarterly to demonstrate sediment movement under normal conditions. Sediment samples
(grabs) will be taken during each sampling event and analyzed for particle size distribution.
Cross-sectional profiles, TSS and turbidity monitoring, and sediment samples will also be taken
after a range of storm events during the pre-removal year. Not every rain event will constitute
monitoring, but monitoring will occur after a range of events (i.e., one thunderstorm and one
frontal event).
2.4.1 Pre-Removal Dredging
Carolina Sand, LLC, in cooperation with Duke, was issued a mining permit on June 10, 2008, by
the NCDENR for the removal of the majority of sand (70,000 cubic yards) in the Dillsboro Pond
prior to removal of the dam. Dredging will be implemented as soon as possible after the FERC
approves Duke's Sediment Management Plan which was submitted in May 2008.
2.5 Reporting Requirements
All chemical and physical water quality monitoring data will be reported to the NCDWQ's
Raleigh Office and the Asheville Regional Office on a monthly basis and within 30 days
following the end of the month of the collections. The fish and macroinvertebrate data will be
reported to the NCDWQ annually by March 1 of each year following collection.
9

Duke Energy Carolinas, LLC Dillsbore Dam Removal
Water Quality and Environmental Monitoring Programs
3.0 Dam and Powerhouse Removal Plan
The decommissioning of the Project will result in the full removal to grade of the existing
Dillsboro Dam and all or the majority of the Powerhouse on the Tuckasegee River. Removal
(currently planned for January-March 2009) will be accomplished by use of hydraulic equipment
to remove the dam and appropriate powerhouse structures in accordance with a staged demolition
plan that is currently being developed and will be available later in 2008. An excavator with a
hoe-ram attachment or similar mechanism will demolish the dam, and an excavator and track
loader will be used to remove the rubbletconcrete (along with any remaining sediment). A
Section 401 (Clean Water Act) Water Quality Certification has been approved and received from
the NCDWQ along with a Section 404 "dredge and fill" permit from the U. S. Army Corps of
Engineers for this action. A communication plan, developed by Duke and the agencies, will also
be prepared and implemented prior to any removal activities.
4.0 Dam Removal Monitoring
During the actual dam demolition and removal period, a regulatory compliance, safety, and
contingency program will be implemented. This program will include environmental parameter
threshold triggers, which, if exceeded, will initiate parameter-specific mitigation measures.
Water quality and quantity triggers will generally result in a temporary suspension of demolition
and/or a decrease in flow (i.e., to lower turbidity levels), or an increase in flows (i.e., to raise DO
levels). These measures will remain effective until ambient conditions return. Ambient
conditions will be established during the pre-removal monitoring phase.
Excessive bank erosion, appearance of depositional bars, or other sediment transport observations
will trigger sediment mitigation responses. Flows will be lowered until bank stabilization devices
can be installed, if deemed necessary. To the extent practical, depositional bars will be removed
by increasing flows from upstream Duke projects.
4.1 Water Quantity and Quality
Turbidity, TSS, DO, temperature, pH, and conductivity will be taken daily at stations upstream
and downstream of the dam (Table 3 and Appendix A) during the demolition of the dam and the
powerhouse substructure. Stream flow measurements will also be documented during this period.
Thresholds based on water quality standards and/or other agency recommendations will be used
to guide continuation of the demolition and removal process. All water quality measurements
will be taken one week prior to removal activities, the day(s) of removal, and the day after
10
Duke Energy Carolinas, LLC Dillsboro Dam Removal
Water Quality and Environmental Monitoring Programs
removal of the dam and powerhouse superstructure. Photographic documentation of removal
conditions will be taken at the monitoring stations described in Table 3.
Table 3. Dam and Powerhouse Removal Phase Monitoring
Monitoring
Station Monitoring
Location Monitoring
Activity Monitoring Period
M1 /Downstream RM 31.1 W Q, Photo I week before and days of demolition
M2 / Downstream Scott's Creek; 0.5
mile upstream of
confluence WQ, Photo 1 week before and days of demolition
M3 / Downstream RM 31.5 W Q, Photo 1 week before and days of demolition
M4 / Upstream RM 33.2 WQ, Photo 1 week before and days of demolition
M5 / Upstream RM 33.6 W Q, Photo 1 week before and days of demolition
TI-TI7 RM 12.3-32.7 Sediment,
Photo Bedload sampling: 3 times during removal
Cross-sectional profiles: monthly
i.-- ruvwstaytis tutu vra uovrumates wni De taKen at all the monitoring locations.
4.2 Sediment
Sediment transport will be monitored monthly during the dam demolition and removal phase at
the specified transects (Table 3). In addition, TSS will be monitored daily and turbidity will be
monitored hourly during periods of dam demolition and removal. If turbidity measurements
below the demolition area exceed upstream measurements by more than 20 Nephelometrie
Turbidity Units, then in-field consultation with the USFWS, the NCWRC, the NCDWR, and the
NCDWQ will occur to determine if demolition should proceed. Bedload sediment sampling will
occur over a 24-hour period three times during demolition activities. One bedload sampler will
be placed upstream of the dam as a control and one will be placed below to measure sediment
movement. The samplers will be deployed at least once during a rain event. Photographs will be
taken during all monitoring at all locations.
Per recommendations made by the FERC and the USFWS, sediment transport flows may be
adjusted during demolition based on water quality and sediment transport observations made
downstream. In addition, a silt curtain may be used, if deemed necessary, to contain sediment
within the pond and immediately downstream. The silt curtain will be monitored regularly during
the demolition and all sediments captured by the silt curtain will be removed to an upland
location.
During removal, sediment deposition within the established downstream sampling stations or
other areas of importance will be monitored and documented. Visual inspection and
it
Duke Energy Carolinas, LLC Dilisboro Dam Removal
Water Quality and Environmental Monitoring Programs
photographic evidence will be used to determine the occurrence and extent of any bank erosion,
both immediately upstream and downstream of the dam.
4.3 Fish Stranding Monitoring
The Fish Stranding Monitoring Plan for the Dillsboro Dam removal will consist of the following
components:
Dillsboro Pond Fish Stranding Monitoring
• Observers will walk each side of the riverbanks upstream of the Dillsboro Dam as water
levels recede during each phase of the dam removal.
• Stranded fish will be netted and returned to areas either upstream or downstream of the dam.
• In the event the reservoir bottom is too steep or too soft for observers to safely recover
stranded fish, the approximate number and species of fish will be recorded.
Tailrace Fish Stranding Monito- rims
The tailwater area downstream of the Project will be monitored for fish stranding or mortalities
during each phase of dam removal.
• Observers will walk each side of the tailwater area downstream of the Project as far down as
the confluence of Scott's Creek.
• Observers will check for stranded fish and take the appropriate steps to net and transport
these fish in an expedient manner to an upstream pool location with suitable water quality.
4.4 On-Site Consultation
Based on the low densities of fish present in Dillsboro Pond, fish stranding is expected to be
minimal or non-existent. However, there is some uncertainty as to level of stranding that may
occur and Duke will conduct on-site consultations with all resources agencies as the Dillsboro
Dam removal proceeds. In this way, plans can be modified based on the field conditions present
on any given day.
5.0 Post-Dam Removal Monitoring
During the post-dam removal period, a program to assess the specific physical, chemical, and
biological changes in the Project area will be conducted. The frequency of post-dam monitoring
is presented in Table 4 and Duke will conduct this monitoring for the first three years following
dam removal. If any man-made debris is found within the footprint of the former reservoir after
12

Duke Energy Carolinas, LLC Dilisboro Dam Removal
Water Quality and Environmental Monitoring Programs
the removal of the dam, all such debris will be removed and disposed of in a proper upland
location.
5.1 Water Quality
Documentation of changes in water quality parameters will be conducted using the methods
described earlier. Photographic documentation of post-removal conditions will be conducted at
the same locations described earlier (Table 4).
Table 4. Post-Removal Phase Monitoring
Monitoring Monitoring Monitoring Monitoring Period
Station Location Activity
M1 /Downstream RM 31.1 WQ, Photo, - WQ, Photo: Monthly for first two
Metal (Nickel) years/quarterly thereafter
- Metal: Annually
M2 / Downstream Scott's Creek; WQ, Photo - WQ, Photo: Monthly for the first two
0.5 mile years/quarterly thereafter
upstream of
confluence
M3 / Downstream RM 31.5-31.6 WQ, Photo, - WQ, Photo, Habitat: Monthly for the first
Habitat, Fish, two years/quarterly thereafter
Macro, Pebble - Fish, Macro, Pebble Counts: May and
Counts October
T6 / Downstream RM 27.2-27.5 Fish, Macro, - May and October
Pebble counts
M5 / Upstream RM 32.9-33.8 WQ, Photo, - WQ, Photo: Monthly for the first two
Fish, Macro, years/quarterly thereafter
Pebble Counts - Fish, Macro, Pebble Counts: May and
October
M7 / Upstream RM 33.6 WQ, Photo - Monthly for first two years/quarterly
thereafter
T1-T17 RM 12.3-32.7 Sediment, - Cross-sectional profiles, Sediment samples,
Photos Fish, Photos: quarterly
Macro, Pebble - Bedload samples, Photos: twice (once each
Counts, Metal year)
(Nickel) - Fish, Macro, Pebble Counts: T13 in May
and October
- Metal:T13 Annually
- - - --- - -----o--r--- -«•.. ?..........,...,.w•w nau w tanclt at all t11G II unnu ng locations.
5.2 Sediment
Sediment monitoring and cross-sectional profile sampling will continue quarterly for three years
following dam removal. The bedload samplers will be deployed for a 24-hour period on two
different occasions after the dam removal. Deployment will take place once each year for the
first two years following dam removal. Attempts will be made to deploy the bedload samplers
13

Duke Energy Carolinas, LLC Dillsboro Dam Removal
Water Quality and Environmental Monitoring Programs
under similar conditions each year (i.e., under typical generation flows and seasonal flows).
Downstream sediment deposition/redistribution monitoring and substrate type analysis will also
be measured along established stations and transacts. All data will be compared to the pre-
removal phase monitoring and analyzed to assess sediment transport before, during, and after
dam removal.
Post-removal monitoring of similar cases has shown that loose unconsolidated sands will tend to
erode when shear stress and velocities exceed critical threshold levels. However, the overall
process can take several years to reach a new equilibrium condition and downstream impacts
have been very limited (Milone and MacBroom 2004).
5.3 Revegetation
Bank and sediment stabilization, and revegetation of the dewatered pond will occur following
dam removal. Photographic stations will be established to document any erosion and/or stream
headcutting within the Project area. In areas of stabilized sediment, vegetation colonization will
be documented through the establishment of sampling plots. Riparian areas within the pond will
be revegetated as needed with native vegetation as described in detail in Duke's Restoration Plan
that was submitted to the FERC earlier this year. It is anticipated that riparian areas downstream
of the Project will not require revegetation.
Because vegetation will not be present on the newly exposed shoreline along the margins of the
former Dillsboro Pond, Duke will take appropriate measures to minimize the erosion of these
disturbed areas, stabilize them as soon as possible, and establish native vegetation as soon as
these areas are ready and planting times permit. Additionally, riparian vegetation, especially
large trees, will be maintained within the Project boundary to the maximum extent possible. The
dredge-staging area will be completely revegetated as soon as the work is completed. It is
anticipated that some erosion from these areas will occur despite the control measures, largely
because vegetation will not provide its maximum protection until 5 to 10 years after it is planted.
In the interim, biodegradable geotextile fabrics, such as a net straw blanket or coconut fiber
blanket, will be installed to stabilize the areas prone to slumping, caving, or subsidence until they
can be stabilized with vegetation.
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Duke Energy Carolinas, LLC Dillsboro Dam Removal
Water Quality and Environmental Monitoring Programs
5.4 Aquatic Resources
Documentation of the upstream and downstream changes in aquatic life such as fisheries and
benthic macroinvertebrates will occur. A yearly report documenting the post-removal monitoring
results will be submitted to the USFWS, NCWRC, and NCDENR upon completion of the
activities. Quarterly and annual summary reports will be submitted to the agencies, as requested.
Action or contingency plans (e.g., remediation) can then be developed and approved by the
pertinent agencies, and implemented if any problems are found during the monitoring period.
5.4.1 Fisheries Monitoring
Fisheries monitoring at the same locations sampled during the pre-removal phase will be
conducted in May and October for three years following dam removal. Additional fish sampling
will be conducted during spring to assess use of areas upstream from the former dam site by
spawning suckers and/or other fishes known only to occur downstream from Dillsboro Dam per
license application data.
5.4.2 Macroinvertebrate Monitoring
Aquatic macroinvertebrate monitoring at the locations and times used in fisheries monitoring will
be conducted. Full scale benthic macroinvertebrate collections will continue during this post-dam
removal period.
5.5 Riparian Habitat
Changes in riparian areas will be documented through use of photographic stations and vegetation
plots located throughout the prior reservoir. The overall quality and change in habitat will be
assessed with the use of a stream habitat evaluation index. Habitat will be assessed within the
impoundment area before and after the dam removal. Changes in habitat quality will be
documented and stream cross-sections will be monitored for long-term changes to channel
morphology.
5.6 Exotics
Any exotic plant, aquatic life, or wildlife introductions due to dam removal will be documented.
5.7 Metal (Nickel) Testing
Nickel monitoring will occur annually (for three years) at one location immediately below the
former Dillsboro Dam (M1) and at one location within the former Dillsboro Pond (downstream of
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Duke Energy Carolinas, LLC
Dillsboro Dam Removal
Water Quality and Environmental Monitoring Programs
T13). All testing will conform to acceptable state standards and will be conducted at a laboratory
certified by the State of North Carolina.
16
Duke Energy Carolinas, LLC Dillsboro Dam Removal
Water Quality and Environmental Monitoring Programs
6.0 Literature Cited
Milone and MacBroom. 2004. Sediment study: relating to the removal of the Dillsboro Dam,
Tuckasegee River, Jackson County, NC. Prepared for Duke Power and Devine Tarbell &
Associates.
Wolman, M.G. 1954. A method for sampling coarse river-bed material. Transactions of the
American Geophysical Journal 35(6):951-956.
17
Duke Energy Carolinas, LLC
Dillsboro Dam Removal
Water Quality Monitoring Program
APPENDIX A
MAP OF PROJECT MONITORING LOCATIONS
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