Appendix-A_Water_Supply_Information

Appendix A
Water Supply Information

TECHNICAL MEMORANDUM

Second Creek Water Supply Expansion Alternatives
PREPARED FOR: City of Kannapolis
PREPARED BY: Chip Smith, P.E.
DATE: November 26, 2002
Executive Summary
Purpose of Study
The purpose of this study is to identify and analyze the feasibility to expanding the
available supply from the Second Creek system by the construction of a proposed reservoir,
and compare it to the development of alternative water supply sources. Alternatives to the
new reservoir would be a new withdrawal from either the Yadkin River near Salisbury or
the Catawba River near Mooresville.
Previous studies performed by the City of Kannapolis indicate the proposed reservoir
would increase the 50 - year safe yield from Second Creek from 2.5 to 9.3 million gallons per
day (MGD). The alternatives developed for this study will be based on providing a similar
water supply. Also included in this study is an assessment on the capacity and operation of
the existing Second Creek pump station and pipeline for continued service in the future.
Alternatives
The three alternatives have been considered for this study previously mentioned are
described as follows: Alternative 1 is to construct a new reservoir just upstream of the
Second Creek pump station. The purpose of this reservoir would be to increase the safe
yield of the Second Creek supply. Previous studies indicate a lake of approximately
494 acres would be created and increase the Second Creek source to 9.3 MGD as shown on
Figure 1. Alternatives 2 and 3 involve pumping raw water from the Yadkin or Catawba
River respectively. Since the reservoir provides a 9.3 MGD supply, Alternatives 2 and 3 shall
also be based on a 9.3 MGD supply so that an analysis of the alternatives is based on equal
contributions. Proposed improvements to infrastructure involving pump stations and
pipelines will be based on a capacity of 7 MGD to supplement the 2.5 MGD safe yield of the
Second Creek facilities. The locations of Alternatives 2 and 3 are shown on Figure 1.
1

Permitting of Alternatives
Alternative 1 – Second Creek Reservoir
In order to implement the Second Creek reservoir alternative, sponsors would be required
meet the following permitting requirements:
• Obtain increased inter-basin transfer certificate from the Environmental Management
Commission (EMC)
• Re-classification of the watershed by the EMC
• 401 Water Quality Certification/404 Dredge and Fill Permit
• Obtain a Dam Safety Permit
These permitting actions would likely result in the need to develop an Environmental
Impact Statement (EIS) in conformance to the North Carolina Environmental Policy Act
(NCEPA) process, and obtaining a Finding of No Significant Impact (FONSI) to permit the
reservoir development. Reservoir creation results in significant impacts to the environment.
Impacts normally include the inundation of wetland areas and the loss of habitat and water
quality function of those areas.
This process involves a significant evaluation of all the potential impacts of the proposed
reservoir and alternatives to the reservoir. In order to obtain the FONSI, mitigation plans
must be developed to the satisfaction of the environmental regulators, and become a
condition of the permit. The possibility exists that a proposed reservoir can go through the
permitting process for many years and still not satisfy environmental regulators, or the
mitigation requirements become too much of a burden to overcome.
Alternative 2 (Yadkin River) and Alternative 3 (Catawba River)
Implementation of Alternatives 2 and 3, which would withdraw water from the Yadkin and
Catawba Rivers respectively, require that each alternative obtain permits from both state
and federal agencies. State agency permits include approval of an inter-basin transfer from
the EMC, and meeting state regulations for water main extensions requiring conformance
with NCEPA requirements.
The reservoirs located on both the Yadkin River and the Catawba River are licensed by the
Federal Energy Regulatory Commission (FERC) for the generation of hydroelectric power.
New raw water intakes that withdraw more than 1 MGD from the reservoirs or requests to
increase existing permitted withdrawals are considered “Industrial Uses” that require FERC
approval to modify the current license. This process is generally a two-step process that first
requires the applicant to obtain written approval from the license holder, and then prepare
an Environmental Assessment (EA) and conduct an Agency Consultation Process.
The current FERC licenses for the Catawba and Yadkin Rivers will be up for renewal
around 2008, and the re-license process has already been initiated. Discussions with the
North Carolina Department of Environment and Natural Resources (NCDENR) Division of
Water Resources revealed FERC may be reluctant to act on new request until that time. This
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SECOND CREEK WATER SUPPLY EXPANSION ALTERNATIVES
might create a significant delay to obtaining additional water through a new intake, and set
direction towards utilization of existing intakes with available capacity in the short term.
Capital Cost Estimates
The cost estimates developed for this study are termed “order-of-magnitude” estimates by
the American Association of Cost Engineers (AACE). An order-of-magnitude estimate is
made without detailed engineering data. The intended use of these estimates is for long-
range planning and not for project control purposes. Order-of-magnitude estimates are
prepared with the use of previous estimates and historical data from comparable work,
costing curves, and estimating guides and handbooks. The estimated capital cost of the
proposed reservoir and the alternatives are provided in Table ES-1 below:
TABLE ES-1
Summary of Opinion of Probable Capital Costs
Second Creek Water Supply Expansion Alternatives
Project Component Alternative 1
Reservoir
Alternative 2
Yadkin River
Alternative 3
Catawba River
Dam and Reservoir Construction $21,700,000 N/A N/A
Raw Water Intake and PS Construction Cost Construction $6,000,000 $6,000,000 $6,000,000
Pipeline Construction Cost $887,000 $9,744,000 $24,112,000
Total Estimated Construction Cost $33,487,000 $15,744,000 $30,112,000
Total Estimated Construction Cost w/ 25% Contingency $41,858,000 $19,680,000 $37,640,000
Land Acquisition $3,660,000 $30,000 $100,000
Home Acquisition $3,000,000 $0 $0
Wetland Mitigation $7,800,000 $0 $0
Permitting $2,000,000 $500,000 $500,000
Engineering Design and Construction Administration @ 15% of
Construction Costs
$5,023,000 $2,362,000 $5,646,000
Total Cost Including Construction, Design, and Permitting $63,341,000 $22,572,000 $43,886,000
3

1 Introduction
1.1 Purpose of Study
The purpose of this study is to identify and analyze the feasibility to expanding the
available supply from the Second Creek system by the construction of a proposed reservoir,
and compare it to the development of alternative water supply sources. Alternatives to the
new reservoir would be a new withdrawal from either the Yadkin River near Salisbury or
the Catawba River near Mooresville.
Previous studies performed by the City of Kannapolis indicate the proposed reservoir
would increase the 50-year safe yield from Second Creek by 2.5 to 9.3 million gallons per
day (MGD). The alternatives developed for this study will be based on providing a similar
water supply.
Included in this study will be the identification of required infrastructure improvements
with budget level cost estimates, identification of regulatory and legal considerations, and
estimated schedule for each alternative. The expected outcome of this study is to identify the
potential costs of the proposed reservoir for comparison to the cost of the alternatives.
1.2 Current Raw Water Supply System
The City of Kannapolis primary raw water supply is from Kannapolis Lake that has a
limited watershed of approximately 10 square miles. However, Kannapolis Lake is
supplemented with raw water transfers from the Coddle Creek Reservoir (Lake Howell)
and Second Creek. The Second Creek supply is pumped by the city to Kannapolis Lake.
According to city staff, the Second Creek pump station is capable of supplying up to 6
MGD; however the 50-year safe yield of the watershed at the pump station location was
determined to be 2.5 MGD in a separate study using 1999 and 2000 minimum pumping
data. This same study determined that the 50-year safe yield of Kannapolis Lake is 5.44
MGD. Including the Second Creek transfer and excess water pumped greater than the 2.5
MGD Second Creek safe yield and a 2.3 MGD transfer from Lake Howell. The total 50 - year
safe yield of the Kannapolis system is currently estimated to be 10.24 MGD.
1.3 Current System Water Demands and Future Needs
Recent master planning efforts undertaken by Cabarrus County indicate growth in the
Kannapolis service area will increase water demands significantly from approximately
8 MGD for an average day (ADD) in 2000 to 14 MGD in 2030. Section 6 of State Water Supply
Plan requires submittal of a plan to alleviate the available supply shortfall when the ADD is
greater than 80 percent of available supply (80 percent criteria). Based on the analysis above,
ADD is now at or just above the 80 percent criteria. Therefore, the safe yield of the
Kannapolis Lake needs to be increased to meet future demands. To meet this demand, an
additional supply source is required to increase the safe yield of Kannapolis Lake from
10 MGD to 17 MGD to meet the 80 percent criteria in 2050. Since the proposed Second Creek
Reservoir increases the safe yield by 6.8 MGD, the development and analysis of the
alternatives will be based on increasing the safe yield by 7 MGD.
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SECOND CREEK WATER SUPPLY EXPANSION ALTERNATIVES
1.4 Description of Alternatives
The three alternatives have been considered for this study previously mentioned are
described as follows: Alternative 1 is to construct a new reservoir just upstream of the
Second Creek pump station. The purpose of this reservoir would be to increase the safe
yield of the Second Creek supply. Previous studies indicate a lake of approximately
494 acres would be created and increase the Second Creek source to 9.3 MGD as shown on
Figure 1. Alternatives 2 and 3 involve pumping raw water from the Yadkin or Catawba
River respectively. Since the reservoir provides a 9.3 MGD supply, Alternatives 2 and 3 shall
also be based on a 9.3 MGD supply so that an analysis of the alternatives is based on equal
contributions. Proposed improvements to infrastructure involving pump stations and
pipelines will be based on a capacity of 7 MGD to supplement the 2.5 MGD safe yield of
Second Creek. Alternative 2 is to construct a new raw water intake on the South Yadkin
River to withdraw 7 MGD. Alternative 3 would do the same on the Catawba River, and is
assumed to be located near Mooresville. The locations of Alternatives 2 and 3 are shown on
Figure 1.
5
Figure 1
Alternatives 1, 2, and 3
Statesville
Lake Norman
Mooresville Irish Buffalo
Creek
Salisbury
Yadkin River
KannapolisKannapolis Lake
Proposed Reservoir
Alternative 1
Existing Second Creek
Pumping Station
Approximate Location
of New Intake and
Pump Station
Approximate Location
of New Intake and
Pump Station
Proposed Route
Alternative 3
30 Inch Pipeline
Second Creek
Pipeline Discharge
Existing 30 Inch
Second Creek Pipeline
Proposed Route
Alternative 2
30 Inch Pipeline
3 30 Miles

2 Existing System Characterization
2.1 Description of Facilities
The Second Creek pump station (PS) is located at the confluence of Second Creek and Sloans
Creek. Steel sheet pile dams across each creek create a pool to allow the withdrawal of
water. The raw water is pumped through a 30 - inch diameter raw water pipeline to the
headwaters of Kannapolis Lake on Irish Buffalo Creek approximately one mile upstream of
NC 1350.
This pipeline is located in a 70 - foot wide easement across farm fields and through several
wooded areas. A horizontal survey of the easement was completed in July 2001. Based on
the results of this survey, the length of this pipeline is approximately 44,800 feet or 8.5 miles.
According to city staff, the Second Creek system was constructed in the 1940s. For cast iron
pipe of this age, a general guideline is to assume that it can only handle an internal pressure
of 100 or 150 pounds per square inch (psi).
2.2 System Hydraulic Conditions
The Second Creek pump station contains a single horizontal pump located inside the pump
station structure approximately 10 to 12 feet above the water surface level. This pump
discharges to the 30 – inch pipeline described previously. Surge protection is provided by a
surge relief line located just downstream of the check valve located at the pump discharge.
According to City staff; this system has a normal pumping capacity of approximately
6 MGD; pumping flows lower than this rate requires increasing system heads by partially
closing valves located on the 30 - inch pipeline to reduce the pump discharge rate.
The pump station has an intake screen that keeps significant sized debris from entering the
pump and clogging it; however suspended sediments in the water are still withdrawn and
pumped into the pipeline. To avoid settlement of suspended sediments in the bottom of the
pipeline, the flow through the pipe should be have a velocity of 2 feet per second (fps) or
greater. At the maximum capacity of 6 MGD, the velocity of the water flow is 1.9 fps. At this
low velocity, sedimentation build up inside the pipeline is a continuous maintenance
problem. In addition, intermittent operation of the pipeline enhances the settlement of
suspended sediments that need cleaning out for each time the pumping operation starts up.
Based on theses operation conditions; the potential exists for the pipe walls to be
experiencing a build up that reduces the pipe’s internal diameter and the capacity of the
system.
A preliminary hydraulic analysis was conducted to develop a hydraulic grade line to
evaluate the existing operating pressures of the pipeline. Due to the age of the pipeline, cast
iron pipe manufactured 50 to 60 years ago has limited design operating pressures. This
analysis is needed to determine how much additional pressure the pipeline can handle if
flows are increased in the future.
This effort was completed by utilizing United States Geological Survey (USGS) quad maps
to estimate the pipeline elevations and the horizontal survey of the 70 - foot wide easement
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SECOND CREEK WATER SUPPLY EXPANSION ALTERNATIVES
described above. The estimated high point of the pipeline is at NC 152 with an elevation of
approximately 895 feet. The elevation of the centerline of the pump is approximately
665 feet, which provides a static head of 230 feet. At 6 MGD through the 30 - inch pipeline
with an assumed Hazen-Williams (H-W) C factor of 100, the friction head is approximately
31 feet. The total dynamic head (TDH) at the pump station is 261 feet or 113 psi maximum
operating pressure. Operating pressures decrease downstream and reach near zero at the
pipeline high point just south of NC 152.
If the “C” factor is much lower like 50, then the friction head increases to 110 feet, the TDH
increases to 340 feet, and the operating pressure to 147 psi, assuming the pump can still
pump 6 MGD at these higher heads. Minimum pressure in the pipeline is approximately
4 psi at the high point just south of NC 152.
2.3 Future Service Life of Pipeline
Long-term water supply planning could result in the need to increase flows through the 30 -
inch pipeline up to 13 MGD. This would allow 6 MGD to continue to be pumped from
Second Creek and an additional 7 MGD be pumped from the Yadkin River.
Separate regional water supply planning efforts underway could result in the need to
ultimately be able to pump 26 MGD through the pipeline. This flow rate allows 6 MGD to
continue pumping from Second Creek and a 20 MGD withdrawal from the Yadkin River.
Increasing the flow rate through the pipeline will result in significant increases in operating
pressure, which will likely require replacement of part or all of the existing pipe. Listed in
Table 1 are the potential flow scenarios and operating conditions.
TABLE 1
Potential Flow Scenarios and Operating Conditions
Second Creek Water Supply Expansion Alternatives
Linear Feet of Pipe
to Replace

Flow
Rate
(MGD)

Flow
Scenario

Year

Pipe
Velocity
(fps)

“C”
Factor

Max
Pressure
(psi)

Min
Pressure
(psi) >115 psi >145 psi
6 Existing 2002 1.9 50 113.0 0.6 N/A N/A
6 Existing 2002 1.9 100 147.2 3.8 N/A N/A
10 Future Reservoir 2010 3.2 100 133.8 2.3 ~6,000 0
13 Future Regional 2010 4.0 100 150.3 3.2 ~20,000 ~2,500
16 Future Regional 2020 5.1 100 179.3 4.8 ~21,100 ~11,300
26 Future Regional 2035 8.3 100 289.7 11.2 ~26,400 ~23,200

Depending on the current “C” factor of the existing pipeline, it should be anticipated that
significant portions of the existing pipe would need to be replaced future flows greater than
10 MGD. This is most likely to occur under a regional water supply approach for flows in
2010 and beyond. However, at that time the pipe will be 60 to 70 years old and at the end of
its expected service life.
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SECOND CREEK WATER SUPPLY EXPANSION ALTERNATIVES
2.4 Short-Term Testing and Improvements
If the long-term plan is to continue operating this system with a capacity of 6 MGD, there
are several recommendations listed as follows:
• Due to the age of the cast iron pipeline, a field inspection of the pipe walls should be
performed at several locations to identify potential corrosion problems and estimate the
pipe structural condition. This inspection would be performed by removing a short
section of the pipe or removing a coupon to inspect the internal and external pipe walls.
In addition, closed-circuit television (CCTV) inspection of some sections should be
performed where feasible.
• Field hydraulic testing should be performed to determine the current Hazen-Williams
“C” factor and to determine its pressure limits.
• Review of the recently completed survey of the 70 - foot easement revealed the pipeline
might not be inside the easement in several locations. Since the 70 - foot easement will be
utilized to either replace this line or install a parallel line from another water supply
source.
• Improve the intake screening system to prevent suspended solids from entering the
pumps and the pipeline.
• Modify existing pump setup for the installation of a second pump to allow pump rates
less than 6MGD to make pump station run times more continuous.
9

3 Infrastructure Improvements of Alternatives
Each of the three alternatives requires substantial infrastructure improvements. Pipelines
are sized for a minimum velocity of 2 fps and max of 8 fps, based on new Ductile Iron Pipe
(DIP). Maximum system pressure is 250 psi before a booster station is required. Listed
below are descriptions of each of the alternatives:
3.1 Alternative 1 (Second Creek Reservoir)
This alternative would develop a water supply reservoir and would involve construction of
a dam across Second Creek as shown in Figure 1. The current capacity of the Second Creek
PS is 6MGD and must be upgraded to 10 MGD in order to pump the additional supply
provided by the reservoir. The upgraded PS should be relocated to the reservoir to with
draw directly from the reservoir. Identifying the proposed site is beyond the scope of this
study, however for the purposes of this analysis it is assumed one mile of new 30 - inch
pipeline would need to be constructed to connect to the existing 30 - inch pipeline.
The proposed reservoir, with a normal pool elevation of 685 feet above mean sea level (msl),
has an area of 500 acres and an operational storage capacity of 9,700 acre-feet. The
impoundment extends westward into Sills Creek and Back Creek.
The proposed impounding structure for the reservoir is an earth dam across Second Creek
approximately 4,400 feet downstream of the confluence of Sills Creek and Back Creek. The
height of the proposed dam is in the range of 40 to 45 feet, extending from the base of the
Second Creek channel (somewhere in the range of 660 and 665 feet msl) to a top of dam
(crest) elevation in the range of 700 to 705 feet msl.
NC State Route 1737 currently crosses the proposed reservoir approximately 1800 feet
upstream of the proposed dam and would be flooded by the reservoir. Under the current
design concept, this two-lane roadway would be relocated along the crest of the proposed
earth dam.
3.1.1 Available Geologic and Soils Information
No geotechnical information is currently available for the proposed dam site. Published
information from the USGS indicates that the site lies within the Charlotte Belt, which is
predominated by plutonic rocks with some large areas of metavolcanic rocks, but very few
metasedimentary rocks. Rock units in the vicinity of the dam site include quartzite, and
foliated to massive medium- to coarse-grained metamorphosed mafic complex and
metamorphosed quartz diorite and tonalite.
Information from the Rowan County Soil Survey describes surface soil materials down to
five feet as follows:
• Left Abutment Area – Hiwasee Clay Loam (ML/CL) weathered from felsic to mafic
metamorphic to igneous rock, or old alluvium. Bedrock is characterized as being greater
than 5 feet deep. Materials are said to be well drained and of moderate permeability. The
water table is greater than 6 feet deep.
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SECOND CREEK WATER SUPPLY EXPANSION ALTERNATIVES
• Valley Area – Chewaka Loam (ML/CL), or recent alluvium. Bedrock is greater than
6 feet deep. Materials are said to be poorly drained with moderate permeability. The
water table is generally located within 0.5 to 1 foot from the surface.
• Right Abutment Area – Pacolet Sandy Loam (ML/CL with SC/MC layers), Cecil Sandy
Loam (ML/CL with SC/MC layers), and Uwharrie Loam (ML/CL) weathered from
felsic or argillite and other fine grained bedrock materials. Bedrock said to be greater
than 6 feet deep, but Saprolite (weathered bedrock) was identified at depths of 3.5 to
4 feet in the soil profiles. The materials are said to be well drained with moderate
permeability. Water table is said to be greater than 6 feet deep.
3.1.2 Hydrological Conditions and Assumptions
The watershed for the proposed Second Creek Reservoir has an area of 34.1 square miles
and a maximum length of 62,000 feet. The area is predominately farm and forested land.
The watershed is drained into two tributaries, Sills Creek and Back Creek. Hillside slopes
from the ridges to these tributaries are on the order of 20 percent.
The total storage capacity of the dam with a crest elevation in the range of 700 to 705 feet
msl is estimated to be in the range of 30,000 to 35,000 acre-feet. Under North Carolina
Administrative Code, Title 15A, Subchapter 2K, Dam Safety (NCAC 15A-2K), this storage
capacity results in a classification as a “Large Dam”. The downstream conditions and
hazard potential have not been surveyed. For purposes of this reconnaissance-level
estimate, it is assumed that there may, now or in the future, be residences in the
downstream floodplain of the dam which would further classify the dam as a High Hazard
Potential (Class C) dam in accordance with NCAC 15A-2K.
For a Large, Class C dam, NCAC 15A-2K requires that the spillway system be designed for
a design storm equal to three-fourths of the Probable Maximum Precipitation (¾ PMP). The
estimated peak inflow rate for the ¾ PMP, from existing watershed information, is on the
order of 76,000 cubic feet per second (cfs), or about 2,230 cfs per square mile. This peak
estimate was based on a 6-hour PMP point rainfall of 29 inches (or ¾ PMP point rainfall of
22 inches) from Technical Paper No. 40, Rainfall Frequency Atlas for the United States, U.S.
Department of Commerce, 1961, peak flow computations using procedures in Section 4,
Hydrology, Soil Conservation Service National Engineering Handbook, 1972, and hydrological
assumptions based on a review of the topographical maps and soils information for the
drainage area.
For this reconnaissance estimate, it is assumed that the spillway system must pass the entire
peak inflow rate for the ¾ PMP design storm, with at least 3 feet of freeboard in the dam.
For estimating purposes, CH2M HILL has assumed an open channel spillway, with 3H:1V
side-slopes extending through the ridge at the right abutment of the dam. This appears to be
the best location for the spillway. This results in the need for an open channel spillway with
a width of approximately 300 feet and a dam crest elevation of 705 feet msl to allow passage
of the ¾ PMP with approximately 3 feet of freeboard.
The resulting spillway and crest height requirements are somewhat conservative since the
reservoir has substantial storage capacity and actual spillway depth and flow during the
design storm will likely be lower than 76,000 cfs once storage is taken into account. The
conservative approach at this level of consideration, however, provides an allowance for
future design refinements, such as providing a service spillway for everyday use and an
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SECOND CREEK WATER SUPPLY EXPANSION ALTERNATIVES
emergency spillway section for rare use, decreasing the spillway side-slopes if competent
rock is encountered.
3.1.3 Assumptions for Dam and Spillway Construction
On the basis of the following information, assumptions on the design and construction of
the dam and spillway have been made:
• The estimate includes only the construction cost for the dam and associated spillway. It
does not include additional costs for engineering, design, permitting, impoundment area
preparation, wetlands mitigation, road relocation, fish ladders, or other items. Those
items are assumed to be in other cost items in the overall project estimate.
• The dam will be a homogeneous earth or earth-rock fill constructed of materials
excavated from native materials. A chimney drain is not considered to be necessary
given the normal pool depth of 25 feet and the accompanying 50 – foot wide crest
necessary to accommodate a two-lane state highway.
• To the extent possible, excavated materials during foundation preparation and spillway
construction will be used for dam construction. Borrow materials required to make up
the difference will be derived from excavations in the reservoir area.
• The top of the dam will have an elevation of 705 feet msl to accommodate the
hydrological assumptions above. The length of the dam at elevation 705 feet msl is
1225 feet.
• The downstream toe of the dam at the maximum section is approximate elevation
660 feet msl, the estimated base of the existing Second Creek channel.
• The crest of the dam will be 50 feet wide to accommodate a two-lane highway (26 feet)
with 12 feet to each side for shoulders, guard rails, signs, monitoring devices, et cetera.
• The upstream and downstream slopes of the dam will be 3H:1V and 2.5H:1V,
respectively.
• The base of the dam will be prepared by removing existing soil materials to a depth of
5 feet in the abutment areas and to depth of 10 feet in the valley area. A keyway, with a
minimum width of 15 feet and a minimum depth of 5 feet will be constructed below the
foundation cut along the centerline of the dam. Keyway and undercut areas will be
back-filled with compacted embankment materials.
• A 2 - foot thick sand and gravel blanket drain will be installed beneath the downstream
slope of the dam in the valley section of the dam.
• A concrete-encased 48 - inch reinforced concrete pipe will be placed through the dam in
the vicinity of the existing Second Creek channel. This pipe will be connected to a 40 –
foot high inlet structure with gates and to a concrete outlet structure.
• The spillway will be a 300 - foot wide channel with 3H:1V side-slopes through the
narrow ridge in the right abutment. The outlet channel will extend around the dam to
the downstream channel. The outlet channel downstream of the main cut will have a
300 - foot width, 3H:1V side-slopes, and a depth of 10 feet where it exits the cut and a
depth of 6 feet where it extends down the slope.
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SECOND CREEK WATER SUPPLY EXPANSION ALTERNATIVES
• Approximately two-thirds of the spillway excavation will be rock excavation with these
materials being removed and used in the dam. (No zoning configuration assumed since
the exact volume of rock is unknown.)
• The last 400 feet of the outlet channel, which exits down a slope into the natural channel,
will be paved with reinforced concrete with an average thickness of one foot. The
remainder of the spillway will be in bedrock.
• A 20 - foot wide strip of riprap, 2 feet thick, will be provided along the upstream slope of
the dam in the vicinity Elevation 685 feet msl for wave action. (The exact configuration
was not developed.)
• A 20 - foot wide strip of riprap, 2 feet thick, will be provided along the downstream toe
of the dam.
3.2 Alternative 2 (Yadkin River)
This alternative would construct a new 7 MGD raw water intake and pump station at a site
on High Rock Lake (a site to be determined) near the confluence of the Yadkin River and
South Yadkin River. The raw water would be pumped through a new 30 - inch pipeline that
would be constructed to the existing Second Creek PS and connect to the existing 30 - inch
pipeline that discharges to the headwaters of Kannapolis Lake. For the purposes of this
study, the pipeline would be located in an existing overhead power line easement from the
intake to the existing Second Creek PS for approximately 58,000 linear feet (11.0 miles) as
shown on Figure 1. Final approval of this location would have to be obtained from the
utility easement owner.
3.3 Alternative 3 (Catawba River)
This alternative would construct a new 7 MGD raw water intake and pump station at a site
on Lake Norman (a site to be determined) near Mooresville. The raw water would be
pumped through a new 30 - inch pipeline that would be constructed to the headwaters of
Kannapolis Lake. For the purposes of this study, the pipeline would generally follow SR 150
from Lake Norman across Interstate 77 and go around the north side of Mooresville to the
intersection with SR 152. From this point the pipeline would follow SR 152 to just west of
Five Points and turn south into the existing 70 - foot wide Second Creek pipeline easement
and terminate adjacent to the Second Creek pipeline discharge point as shown on Figure 1.
Total length of the pipeline route is approximately 88,000 linear feet (16.7 miles).
13

4 Regulatory Permitting Considerations
4.1 Alternative 1 (Second Creek Reservoir)
In order to implement the Second Creek reservoir alternative; sponsors would be required
to complete an Environmental Impact Statement (EIS) following North Carolina
Environmental Policy Act (NCEPA) process. Secure a 401 Water Quality Certification/404
Dredge and Fill Permit; and obtain a Dam Safety Permit. In addition, the Second Creek
watershed could require request reclassification by the Environmental Management
Commission. This would require preliminary contacts with the Divisions of Water Quality
and Environmental Health, a formal reclassification request, a water supply suitability
study, and rule-making action by the EMC including a public hearing. Local governments
within the watershed would also be required to implement water supply protection
requirements depending on the water supply classification deemed appropriate for the new
reservoir and watershed.
In the past decade, the proposed development of new surface water reservoirs has been the
subject of heavy scrutiny by environmental regulators. Reservoir creation results
insignificant impacts to the environment. Impacts normally include the inundation of
wetland areas and the loss of habitat and water quality function of those areas. The
development of a reservoir will like require the preparation of an Environmental Impact
Statement (EIS) in accordance to the National Environmental Policy Act (NEPA). The EIS
process and obtaining a Finding of No Significant Impact (FONSI) to permit the project is
usually a very lengthy and expensive process.
This process involves a significant evaluation of all the potential impacts of the proposed
reservoir and alternatives to the reservoir. In order to obtain the FONSI, mitigation plans
must be developed to the satisfaction of the environmental regulators, and become a
condition of the permit. The possibility exists that a proposed reservoir can go through the
permitting process for many years and still not satisfy environmental regulators or the
mitigation requirements become too much of a burden to overcome.
4.1.1 Environmental Considerations
The full range of potential impacts to the environment would be identified during the
development of an EIS. However, permanent impacts to wetlands would result by
construction of the reservoir. Locations of wetlands were identified from the National
Wetlands Inventory database. A detailed field investigation would be required during the
EIS process to delineate wetlands in accordance with the USACE protocol. Listed below are
some initial environmental impacts of the proposed reservoir:
1. Inundation of 500 acres for the reservoir would result in loss of approximately 104 acres
of existing wetlands and other natural habitat.
2. The 500 acre reservoir would result in a loss of agricultural and rural lands and could
impact cultural/historical properties as well.
3. Existing property owners that are located in the area of the proposed reservoir would
have to be relocated.
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SECOND CREEK WATER SUPPLY EXPANSION ALTERNATIVES
4.1.2 Dam Safety Design Standards
The North Carolina Department of the Environment and Natural Resources (NCDENR) has
jurisdiction over dam safety. In accordance with the Dam Safety Law of 1967 (NCAC 143-
215.25A), an application for dam construction must be filed and approved by the Division of
Land Resources prior to construction of a dam. Administrative rules for meeting the design,
construction, permitting, maintenance, minimum stream flows, and other requirements of
the Dam Control Law are contained in North Carolina Administrative Code, Title 15A,
Subchapter 2K, Dam Safety. Under the administrative rules, dams are classified by size and
hazard classification. Size refers to the height and storage capacity. Hazard classification
refers to the potential losses should the dam fail and does not reflect the condition of the
dam.
Since the proposed dam and reservoir would impound 30,000 to 35,000 acre-feet, it would
be classified as a Large Dam based on DENR administrative rules. Large Dams impound
7,500 to 50,000 acre-feet, or are 50 and 100 feet high.
Residences are located, or could be located, within the floodplain downstream of either dam
site and there is likely a potential for loss of life if the dam were to fail - resulting in a High
Hazard (Class C) classification for either dam site. This requires that the dam and outlet
works be designed to safely pass a Spillway Design Flood equivalent to at least the ¾ PMP.
4.2 Alternatives 2 (Yadkin River) and 3 (Catawba River)
Construction of a new raw water intake and pipeline from either the Yadkin River or the
Catawba River would require permits from both the state and federal government.
4.2.1 State Regulations on Inter-Basin Transfers of Water
The proposed withdrawal of water from either the Yadkin or the Catawba River would
result in an inter-basin transfer of water to the Rocky River basin. North Carolina Statute G.
S. 143- 215.22G & G. S. 143.215.22I and North Carolina Administrative Code Section T15A:
02G. 0400, adopted in January of 1994 and modified in 1997 and 1998 regulate surface water
transfers in the state. An inter-basin transfer (IBT) certificate is required from the North
Carolina Environmental Management Commission (EMC) for new transfers of 2 million
gallons per day (MGD) or more (maximum daily demand [MDD]) or once the amount of
water transferred from one sub-basin to another reaches the full capacity of the transfer
facilities that were existing or under construction as of July 1, 1993 (referred to as the
grandfathered capacity).
Prior to EMC consideration of an IBT, the NCEPA process must be completed including an
Environmental Assessment and FONSI or completion of an EIS. Following the NCEPA
process, the EMC will accept a petition for an IBT Certificate and begin the process for
reviewing and approving the IBT.
4.2.2 State Regulations for Water Main Extensions
State regulations (15A NCAC 01C .0100 – 0.0500) establishes procedures and regulations for
the extension of water mains, sanitary sewer, and other utility infrastructure expansions and
new facilities that must conform to the North Carolina Environmental Policy Act (NCEPA).
The regulations require the development of environmental documents for water and
wastewater treatment facilities and expansions. In addition, water main extensions must
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SECOND CREEK WATER SUPPLY EXPANSION ALTERNATIVES
comply if they are greater than 5 miles in length, and sewer mains greater than 3 miles in
length; unless site specific adverse environmental consequences are identified.
4.2.3 Federal Regulations
The reservoirs located on both the Yadkin River and the Catawba River are licensed by the
Federal Energy Regulatory Commission (FERC) for the generation of hydroelectric power.
These licenses were granted to Alcoa Power Generating Inc.(AGPI) for the Yadkin River,
and Duke Power for the Catawba River. The FERC license holder is required to operate and
manage the reservoir in accordance to the terms of its license and FERC rules and
regulations to avoid compromising the reservoir’s environmental and recreational values or
the needs of the license holder to generate hydroelectric power.
New raw water intakes that withdraw more than 1 MGD from the reservoirs or requests to
increase existing permitted withdrawals are considered “Industrial Uses” that require FERC
approval to modify the current license. This process is generally a two-step process that first
requires the applicant obtain written approval from the license holder, and then prepare an
Environmental Assessment (EA) and conduct an Agency Consultation Process. Since an IBT
certificate must also be obtained from the state, there should be a significant overlap in most
of the documentation required for each. However, the FERC EA will require identification
of the proposed intake type and location; which will require completion of preliminary
engineering of the intake design and pumping facilities if located near the shoreline.
The current FERC licenses for the Catawba and Yadkin Rivers will be up for renewal
around 2008, and the re-license process has already been initiated. Discussions with the
NCDENR Division of Water Resources revealed FERC may be reluctant to act on new
request until that time. This might create a significant delay to obtaining additional water
through a new intake; and set direction towards utilization of existing intakes with available
capacity in the short term.
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5 Estimates of Probable Cost
The order-of-magnitude estimates in this technical memorandum (TM) are prepared with
the use of costing curves, previous estimates and historical data from comparable work, and
estimating guides and handbooks. Anticipated construction cost are then converted to
capital costs to identify the potential total cost of each alternative. An industry standard
contingency factor of 25 percent is applied to each alternative’s base cost.
5.1 Definitions of “Order-of-Magnitude” Estimates
The cost estimates contained in this TM are termed “order-of-magnitude” estimates by the
American Association of Cost Engineers (AACE). An order-of-magnitude estimate is made
without detailed engineering data. The intended use of these estimates is for long-range
planning and not for project control purposes. Order-of-magnitude estimates are prepared
with the use of previous estimates and historical data from comparable work, costing
curves, and estimating guides and handbooks. They have an expected accuracy of plus 50
percent and minus 30 percent of the estimated cost. These percentages should be viewed as
statistical confidence limits and should not be confused with the contingencies.
The cost estimates shown, and any resulting conclusions on project financial feasibility or
funding requirements, have been prepared from available information at the time of the
estimate for guidance in project evaluation or implementation. Final project costs and
resulting feasibility will depend on actual labor and material costs, competitive market
conditions, actual site conditions, final project scope, implementation schedule, continuity of
personnel and engineering, and other variable factors. As a result, final project costs will
vary from the estimates presented here. Because of these factors and to help ensure proper
project evaluation and adequate funding, project feasibility, benefit/cost ratios, risks, and
funding needs must be carefully reviewed prior to making specific financial decisions or
establishing project budgets.
For an order-of-magnitude estimate, CH2M HILL standard practice is to apply a 25 to 30
percent contingency. While the estimate is grounded in an understanding of the basic
project, additional information beyond what is presently available will affect the
preliminary design and project cost.
Assumptions of particular note used in developing these estimates include the following:
5.2 Dam Construction
There is currently uncertainty as to the suitability of bedrock/soil in the proposed spillway
cut to accommodate design flow velocities. If the existing materials are unsuitable, the entire
spillway section may have to be paved to the design depth. This single item could increase
the base estimate from 15 to 20 percent. Due to the current site uncertainties, the upper end
of this range has been used in the order-of-magnitude project costs.
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Additional Considerations:
• There is a potential for some savings with a roller compacted concrete (RCC) dam,
provided that the road can be relocated off the dam and the volume of the RCC dam
could be decreased to about 30 percent of the volume of the proposed earth dam.
Another major benefit of an RCC dam, at least at this level of consideration, is that the
spillway could be made an integral part of the RCC dam, deleting the need and
uncertain final design requirements for a large channel spillway in the right abutment.
• The suitability of the site for a RCC dam, and design requirements for either an RCC
dam or an earth dam with a channel spillway, cannot be determined for sure until the
subsurface conditions, especially those in relation to the location and condition of
bedrock at the site, have been determined. The next logical step in the evaluation process
would be, at least, an initial field investigation targeting specific data points necessary to
identify the path forward. The initial investigation could then be followed up later by a
more detailed analysis targeting specific data needs of the selected type of dam,
roadway relocation, et cetera.
5.3 Raw Water Intakes/Pump Stations and Transmission Mains
The construction costs for raw water intakes, transmission pipelines, and pump stations
were developed using the costs of WSACC Master Plan similar type planning projects. For
pipelines, a “length” contingency has been added to account for minor variations in the
pipeline route that could make the final route longer. This was achieved by adding a 15
percent contingency to the estimate. Pipeline costs are then presented in a cost per mile
average for the different pipe diameters. Listed below is a summary of the construction
costs used:
• 7 and 10 MGD raw water PS and Intakes = $6 Million each
• 30–inch pipeline for Alternatives 1 and 2 averages $168 per linear foot because the rural
nature of the pipeline route. Alternative 1 at 5,280 linear feet is $887,000. Alternative 2 at
58,000 linear feet is $9,744,000.
• 30-inch pipeline for Alternative 3 averages $274 per linear foot because of the urbanized
area around Mooresville. At 88,000 linear feet, the cost would be $24,112,000.
The pipeline construction costs include appropriate allowances for easement acquisitions,
tunneling under road ways, and construction cost contingencies.
5.4 Site Acquisitions
The City has purchased some of the property that would be inundated by the reservoir. For
the purposes of this study, it was assumed that half of the land area under elevation
700 feet, which is 366 acres, would still need to be purchased. Research of similar-type
properties for sale in September 2002 near the proposed reservoir indicated the average cost
was approximately $10,000 per acre. This cost is approximately $3,660,000.
Site acquisitions are also required for the proposed raw water intake and pump station for
Alternatives 2 and 3. For the purposes of this study, it is assumed a one-acre site is required.
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SECOND CREEK WATER SUPPLY EXPANSION ALTERNATIVES
The proposed pump station site on the Yadkin River (High Rock Lake) is assumed to be
$30,000 per acre, and Catawba River (Lake Norman) is $100,000 per acre.
5.5 Home Purchases
For the reservoir, it was assumed approximately 20 homes would be have to be purchased.
Research of similar-type properties for sale in September 2002 near the proposed reservoir
indicated the average cost was approximately $150,000 per home. This cost is approximately
$3,000,000.
5.6 Wetlands Mitigation
Permanent impacts to wetlands are limited to the reservoir. Locations of wetlands were
based on the National Wetlands Inventory database. A detailed field investigation would be
required during the Environmental Impact Statement (EIS) process to delineate wetlands in
accordance with the United States Army Corps of Engineers (USACE) protocol. For this
study, the extent of wetlands needing mitigation was estimated based on an average ratio of
2.6 acres per acre impacted. The cost for restoration was assumed to be an average of
$30,000 per acre mitigated (based on North Carolina Department of Transportation
(NCDOT) project costs). The reservoir would require the mitigation of approximately
260 acres for a cost of $7,800,000.
Table 2 provides a summary of cost estimates for both of the proposed alternative sites
(based on increasing existing Second Creek water supply to 10 MGD). A detailed
breakdown of the costs for each alternative is provided in Appendix A.
TABLE 2
Summary of Opinion of Probable Costs
Second Creek Water Supply Expansion Alternatives
Project Component Alternative 1 Alternative 2 Alternative 3
Dam and Reservoir Construction $21,700,000 N/A N/A
Raw Water Intake and PS Construction Cost Construction $6,000,000 $6,000,000 $6,000,000
Pipeline Construction Cost $887,000 $9,744,000 $24,112,000
Total Estimated Construction Cost $33,487,000 $15,744,000 $30,112,000
Total Estimated Construction Cost w/ 25% Contingency $41,858,000 $19,680,000 $37,640,000
Land Acquisition $3,660,000 $30,000 $100,000
Home Acquisition $3,000,000 $0 $0
Wetland Mitigation $7,800,000 $0 $0
Permitting $2,000,000 $500,000 $500,000
Engineering Design and Construction Administration @ 15% of
Construction Costs
$5,023,000 $2,362,000 $5,646,000
Total Cost Including Construction, Design, and Permitting $63,341,000 $22,572,000 $43,886,000
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References
Rowan County Soil Survey
Section 6 of State Water Supply Plan
USGS published info regarding Charlotte Belt rock formations
Under North Carolina Administrative Code, Title 15A, Subchapter 2K, Dam Safety (NCAC
15A-2K)
Technical Paper No. 40, Rainfall Frequency Atlas for the United States, U.S. Department of
Commerce, 1961
Section 4, Hydrology, Soil Conservation Service National Engineering Handbook, 1972

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