CMUD_IBT_Petition_final

C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc i
Table of Contents
Acronyms/Abbreviations..............................................................................................................................ii
Executive Summary................................................................................................................................ES-1
SECTION 1 Requested Action..............................................................................................................1-1
1.1 Requested Action ...................................................................................................1-1
1.2 Background.............................................................................................................1-1
1.3 Project Description.................................................................................................1-4
SECTION 2 Summary of IBT Certification Process............................................................................2-1
SECTION 3 Evaluation Considerations...............................................................................................3-1
3.1 Need for Proposed IBT..........................................................................................3-1
3.2 Alternatives to the Proposed IBT.........................................................................3-3
3.3 Present and Future Impacts on Catawba River Subbasin (Source Basin)......3-5
3.4 Present and Future Impacts on the Rocky River Subbasin (Receiving Basin)3-8
3.5 Other Considerations...........................................................................................3-10
SECTION 4 Compliance and Monitoring Plan.....................................................................................4-1
4.1 IBT Calculation........................................................................................................4-1
4.2 Reporting .................................................................................................................4-3
SECTION 5 Drought Management Plan...............................................................................................5-1
SECTION 6 References.........................................................................................................................6-1
Appendices
A. Finding of No Significant Impact (FONSI)
B. Resource Agency and Stakeholder Comments
C. Summary of Local Regulations and Programs for Mitigation of Adverse Impacts
List of Figures
1 Project Study Area.........................................................................................................1-3
List of Tables
1-1 Characteristics of Lake Norman, Mountain Island Lake, and Lake Wylie...........1-2
3-1 Projected Mecklenburg County Population and Population Served by CMUD..3-1
3-2 CMUD Raw Water Demand Projections....................................................................3-2
3-3 Interbasin Transfer Water Balance Table (Maximum Day Basis)...........................3-3
3-4 Maximum Day Water Use, Discharge, and Interbasin Transfer (mgd) for
CMUD Alternatives in 2030..........................................................................................3-4
4-1 Maximum Day Water Use, Discharge, and Interbasin Transfer (mgd) for
CMUD Alternatives in 2030..........................................................................................4-2
5-1 Target Level for Lake Norman and Mountain Island Lake......................................5-1
5-2 Minimum Flow Requirements for Duke’s Catawba Wateree Project......................5-2
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc ii
Acronyms/Abbreviations
ADD average daily demand
CMUD Charlotte-Mecklenburg Utilities
cfs cubic feet per second
DENR North Carolina Department of Environment and Natural Resources
DWQ North Carolina Division of Water Quality
DWR North Carolina Division of Water Resources
EA environmental impact assessment
EMC North Carolina Environmental Management Commission
FERC Federal Energy Regulatory Commission
FONSI Finding of No Significant Impact
fps feet per second
ft feet
IBT interbasin transfer
JASO July, August, September, October
MDD maximum daily demand
mgd million gallons per day
msl mean sea level
NCEPA North Carolina Environmental Policy Act
NPDES National Pollutant Discharge Elimination System
RRR Rocky River Regional
SC DHEC South Carolina Department of Health and Environmental Control
SC DNR South Carolina Department of Natural Resources
SNHAs Significant Natural Habitat Areas
USGS U.S. Geological Service
WRF water reclamation facility
WSACC Water and Sewer Authority of Cabarrus County
WTP water treatment plant
WWTP wastewater treatment plant
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc ES-1
Executive Summary
Charlotte-Mecklenburg Utilities (CMUD) is requesting an increase from the grandfathered
Interbasin Transfer (IBT) of 16.1 million gallons per day (mgd) to 33 mgd (maximum day
basis). The proposed IBT is based on additional water withdrawals from Lake Norman and
Mountain Island Lake in the source basin (Catawba River Subbasin). IBT will increase due
to transfer of the water to the receiving basin (Rocky River Subbasin) via consumptive use in
eastern Mecklenburg County and existing discharges at Mallard Creek Wastewater
Treatment Plant [WWTP] and Water and Sewer Authority of Cabarrus County’s [WSACC]
Rocky River Regional (RRR) WWTP. CMUD is requesting a permitted IBT increase to 33
mgd, which will allow CMUD to meet projected water supply demands through the year
2030 in eastern Mecklenburg County. This IBT does not include transfers associated with
water or wastewater service provided to the Goose Creek watershed in the Town of Mint
Hill in Mecklenburg County.
Per the requirements of North Carolina General Statute 143-215.22I, an environmental
evaluation was conducted to support the IBT Petition. An Environmental Assessment (EA)
evaluated the direct, secondary, and cumulative environmental impacts of the IBT on the
source and receiving basins.
In the source basin, storage in and flow through the Catawba-Wateree Project reservoirs,
lost electrical generation, and reduced flow in the Catawba River immediately below the
Wylie development would be the major resources directly affected. The indirect and
cumulative impacts on fisheries and aquatic resources, water quality, threatened and
endangered species and other resources would result primarily from changes in flow or lake
levels. Operations of the Catawba-Wateree Project reservoirs were modeled using Duke
Power’s reservoir operations model during average, dry, and drought year conditions. The
estimated change in lake levels and flows that would result from the proposed CMUD
withdrawals during the entire year and during the season of lowest flows (July-August-
September-October [JASO]) were simulated.
The model results indicated that there will be no changes in the surface water elevations of
Lake Norman, Mountain Island Lake, or Lake Wylie due to the proposed increased IBT.
Under normal and drought inflow conditions, Duke Power would manage the lakes and its
power generation to offset increased water withdrawals to maintain the minimum release
requirements and operating lake surface elevations. Direct impacts on water supply, water
quality, wastewater assimilation, fish and wildlife resources, navigation, recreation, or
hydroelectric power generation are not expected since there will be no major changes in the
hydrology of the system due to the increased withdrawal. The IBT will not require
additional permitted wastewater discharges or any construction in either the source or
receiving basins.
There are no secondary impacts on water supply related to growth due to the transfer of
water from the source basin. However, the IBT will provide additional water supply to
support additional growth and development in the receiving basin. Mitigation measures
presented in this IBT Petition are expected to mitigate secondary impacts related to growth
and development. The proposed IBT will not result in significant cumulative impacts in
either the source or receiving basins.
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SECTION 1
Requested Action
1.1 Requested Action
Charlotte-Mecklenburg Utilities (CMUD) is requesting an interbasin transfer (IBT) certificate
from the North Carolina Environmental Management Commission (EMC) for an increase in
their IBT from 16.1 million gallons per day (mgd) (calculated based as the grandfathered
amount based on capacity to transfer as of July 1, 1993) to 33 mgd. The proposed IBT is
based on expansion of the existing water withdrawals from the source basin (Lake Norman
and Mountain Island Lake within the Catawba River Subbasin), and transfer of the water to
the receiving basin (Eastern Mecklenburg County within the Rocky River Subbasin) via
consumptive use and existing discharges in the receiving basin (Mallard Creek Wastewater
Treatment Plant [WWTP] and Water and Sewer Authority of Cabarrus County’s [WSACC]
Rocky River Regional (RRR) WWTP).
The IBT calculation is based on projected growth through 2030 and existing wastewater
treatment facilities in the receiving basin. This IBT does not include transfers associated with
water or wastewater service provided to the Goose Creek watershed in the Town of Mint
Hill in Mecklenburg County.
This IBT petition provides supporting documentation as required by North Carolina
General Statute 143-215.22I; more detailed documentation of the environmental impacts of
the requested action are contained in the Environmental Assessment (EA) (CH2M HILL, 2001)
submitted to the State Clearinghouse on August, 2001. Appendix A contains the Finding of
No Significant Impact (FONSI) for the EA.
1.2 Background
Lake Norman, Mountain Island Lake, and Lake Wylie, which are part of the Catawba River
basin and are located partially in Mecklenburg County, are the final three lakes in a series of
seven hydropower impoundments along the Catawba River in North Carolina. The
impoundments are owned by Duke Power. Mountain Island Lake and Lake Wylie were
built between 1904 and 1928, and Lake Norman was completed in 1967. All three lakes are
extensively used for power generation and recreation, as well as water supply. Table 1-1
summarizes the lake characteristics.
Lake Norman is the largest and most upstream of three reservoirs on the Catawba River in
Mecklenburg County and was used as the water supply source for the towns of Davidson,
Huntersville, and Mooresville. It recently became a source for the CMUD (a City of
Charlotte Department), which supplies water to the City of Charlotte and most of
Mecklenburg County.
Mountain Island Lake is the smallest of the three reservoirs and is fed by releases from Lake
Norman. It was the only water supply source for the City of Charlotte through CMUD until
the recent completion of the intake from Lake Norman; however, Mountain Island Lake is
still the main CMUD water supply source. Lake Wylie is the southernmost lake in
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TABLE 1-1Characteristics of Lake Norman, Mountain Island Lake, and Lake Wylie
Characteristic Lake Norman Mountain Island Lake Lake Wylie
Year Completed 1967 1923 1904-1928
Drainage Area (sq. miles) 1793 1860 3020
Average Depth (feet) 34 16 23
Maximum Depth (feet) 120 30 92
Normal Pool Elevation (ft msl) 760 647.5 569.4
Maximum Drawdown (feet) 15 10 10
Shoreline Length (miles) 520 61 330
Surface Area (sq. miles) 51 5 19
Volume (billion gallons) 356.1 18.7 90.5
Mecklenburg County, forming the boundary to York County, South Carolina, and is the
water supply source for the City of Rock Hill, South Carolina.
There are three water treatment plants (WTPs) that supply Charlotte and most of
Mecklenburg County with potable water: Franklin, Vest, and North Mecklenburg. Due to
continued growth and new facilities (i.e., the new intake and North Mecklenburg WTP and
the expansion of the Franklin WTP), water withdrawal has or will increase from Lake
Norman and Mountain Island Lake in the Catawba River Basin.
Four out of five of CMUD’s WWTPs discharge back into the Catawba River Basin. The fifth,
CMUD’s Mallard Creek WWTP, is located in northeast Mecklenburg County and discharges
to Mallard Creek in the Yadkin-Pee Dee River Basin. Additional CMUD wastewater is
treated at the Water and Sewer Authority of Cabarrus County’s (WSACC) RRR WWTP,
which discharges to the Rocky River. Both of these WWTPs discharge into the Rocky River
Subbasin in the Yadkin-Pee Dee River Basin. The locations of the WWTPs are shown on the
map of the study area (see Figure 1).
Water use in CMUD’s service area, including the portion in the Rocky River Subbasin, is
increasing. As water use in the Rocky River Subbasin increases, CMUD has recently
increased its use of wastewater treatment facilities in that basin by transferring flows to the
RRR WWTP through a contractual arrangement with WSACC and expanding the Mallard
Creek WWTP. The additional use and discharge of water in the Rocky River Subbasin
(through existing permitted capacities) will result in an increase in CMUD’s IBT from the
Catawba River Subbasin to the Rocky River Subbasin.
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1.2 Project Description
CMUD is requesting an IBT of 33 mgd (based on 2030 needs) from the EMC. The proposed
IBT involves transfer of water from the Catawba River Subbasin (source basin) to the Rocky
River Subbasin (receiving basin), as shown in Figure 1 and described below.
• Catawba River Subbasin (source basin): Lake Norman, Mountain Island Lake, Lake
Wylie, and the Catawba River from Lake Norman to the Wylie Dam.
• Rocky River Subbasin (receiving basin): The Mecklenburg County portion east of the
ridge line with the exception of the Goose Creek watershed. The study area includes
Mallard Creek from the WWTP discharge point downstream to the confluence of the
Rocky River proceeding along the Rocky River to the intersection with NC 205.
The IBT associated with future water service into the Goose Creek watershed in
Mecklenburg County is being addressed separately. Thus, the entire Goose Creek
watershed is outside the study area of this project. The requested IBT of 33 mgd does not
include transfers associated with the Goose Creek watershed
CMUD’s current water supply system serves approximately 95 percent of Mecklenburg
County with plans to supply 100 percent by 2020. Approximately 70 percent of
Mecklenburg County is in the Catawba Basin, while the remaining 30 percent is in the
Yadkin-Pee Dee Basin; therefore, a portion of the water that is withdrawn from the Catawba
Basin is actually supplied to residents of Mecklenburg County in the Yadkin-Pee Dee Basin.
Some of the water that is supplied from the Catawba Basin to the Yadkin-Pee Dee Basin in
Mecklenburg County remains in the Yadkin-Pee Dee Basin due to consumptive uses such as
irrigation and on-site wastewater disposal (septic) systems. The remainder of this water is
directly discharged to the Rocky River Subbasin as treated wastewater from the Mallard
Creek WWTP and the RRR WWTP. The RRR WWTP primarily serves Cabarrus County but
also receives some Mecklenburg County flows under a contractual agreement with WSACC.
The Mallard Creek WWTP serves primarily Mecklenburg County customers.
The greater Charlotte metropolitan region has enjoyed a healthy economy for most of this
century, resulting in steady population growth and economic development. Based on land
use projections, it is predicted that similar growth patterns will continue and will increase
the demand for water and wastewater services. Population and water demand projections
are presented in Section 3. The IBT associated with the increased withdrawal from the
Catawba River Subbasin and the increasing flows to the Rocky River Subbasin is expected to
be 32.8 mgd (rounded to 33 mgd) maximum day in 2030. This IBT amount does not include
transfers associated with the Goose Creek watershed.
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SECTION 2
Summary of IBT Certification Process
In 1998, CMUD initiated the IBT Certification process, in consultation with the Division of
Water Resources (DWR), by developing a Scoping Document related to the contents of the
IBT Petition. In early 1999, in compliance with North Carolina General Statute 143.215.22I,
the development of an EA was initiated to examine the impacts of the proposed IBT and for
use in the certification process.
The EA process has included involvement, input, and comment from federal and state
agencies, local municipalities, other stakeholders, and the public. Initial comments from this
initial public involvement phase were received in early 1999, including comments from the
South Carolina Department of Natural Resources (SC DNR) and the South Carolina
Department of Health and Environmental Control (SC DEHC). In July 1999, a Draft EA was
introduced to the North Carolina DENR for review. Subsequently, several correspondence
and meetings between the Petitioner and the resource agencies took place since the second
half of 1999 to early 2001. These efforts culminated in submittal of the final EA to DWR in
April 2001 and the introduction of the EA to the State Clearinghouse in August 2001.
A summary of the comments from resource agencies, stakeholders, and the public from the
scoping process through the completion of the EA is presented in Appendix B.
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SECTION 3
Evaluation Considerations
For ease of review, this section is organized according to the items the EMC is required to
evaluate according to North Carolina General Statute 143-215.22I.
3.1 Need for Proposed IBT
3.1.1 Population Projections
The Mecklenburg County population projections as presented in Table 3-1 are based largely
on Charlotte Chamber of Commerce projections through 2010. While these projections are
slightly higher than projections by others, past Chamber estimates have most accurately
matched recent population levels. Projections beyond 2010 more closely match long-term
projections by the Mecklenburg County Planning Commission. Starting with 1997 U.S.
Census data, the projections represent about a 2.6 percent annual increase through 2010,
decreasing to 1.3 percent in 2030. It is also assumed that 100 percent of the County
population will be served by CMUD by 2020.
TABLE 3-1Projected Mecklenburg County Population and Population Served by CMUD
Year
Projected Mecklenburg
County Population Percent Served Population Served
1997 613,310 95% 584,000
2000 662,000 96% 636,000
2010 830,000 98% 813,000
2020 968,000 100% 968,000
2030 1,101,000 100% 1,101,000
Source: Charlotte Chamber of Commerce projections through 2010, transitioned to Mecklenburg County
Planning Commission projections in 2030 cited in CH2M HILL (2000).
Completion of the I-485 loop around Charlotte is expected to spur growth in the northeast
region of Mecklenburg County. This will increase the percentage of CMUD customers in the
Rocky River Subbasin from the current 16 percent to about 28 percent in 2030.
3.1.2 Water Demand Projections
The CMUD raw water demand projections presented in Table 3-2 are based on population
projections. The projections take into account added residential and nonresidential
customers, as well as regular bulk sales to the Carowinds amusement park.
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TABLE 3-2
CMUD Raw Water Demand Projections
Year ADD (mgd) MDD (mgd)
2000 102.8 154.1
2010 125.9 188.8
2020 146.0 219.1
2030 163.5 245.2
Source: Based on population estimates from Table 3-1.
ADD = Average Daily Demand
MDD = Maximum Daily Demand
mgd = million gallons per day
3.1.3 Need for Additional Water Supply
The intake facilities are permitted by the Federal Energy Regulatory Commission (FERC) for
a maximum instantaneous withdrawal rate of 108 mgd from Lake Norman and 165 mgd
from Mountain Island Lake (i.e., both intakes in the Catawba River Basin). Currently the
combined maximum daily withdrawal rate is 273 mgd. Duke Power is submitting an
application to FERC on behalf of CMUD requesting an increase in the Mountain Island Lake
withdrawal from 165 mgd to 330 mgd (instantaneous maximum) to meet projected
demands through 2030 in Mecklenburg County.
The County operates three major WTPs. The current capacity of the North Mecklenburg
WTP is 18 mgd; there is no raw water storage at this facility. CMUD has plans to increase
the capacity of the North Mecklenburg facility. Franklin and Vest WTPs have capacities of
144 and 24 mgd, respectively. Raw water storage for these two plants total 350 mgd. Taking
into account pumping practices during off-peak hours and raw water storage, currently
CMUD has the capacity to meet average daily demands (ADD) of 145 mgd.
As previously mentioned, CMUD’s current water supply system serves approximately 95
percent of Mecklenburg County with plans to supply 100 percent by 2020. Approximately
70 percent of Mecklenburg County is in the Catawba River Basin, while the remaining 30
percent is in the Rocky River Subbasin; thus any increased water demands in eastern
Mecklenburg County will result in an IBT.
3.1.4 Reasonableness of IBT Request
Based on the water demand projections for the Catawba River Subbasin and the estimated
wastewater discharge to the Rocky River Subbasin, the IBT calculation is presented in Table
3-3. The following assumptions apply:
• Customer consumptive use includes in-basin water uses such as irrigation and septic
systems and is assumed to be 22 percent of raw water withdrawal based on discussions
with DWR staff. WTP losses of 1.4 percent are included in total consumptive use
estimates.
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• In 2000, 85 percent of CMUD’s water supply goes to users within the Catawba River
Subbasin; this falls to 75 percent in 2030. The remaining water is supplied only to CMUD
customers in the Mecklenburg County portion of the Rocky River Subbasin.
TABLE 3-3
Interbasin Transfer Water Balance Table (Maximum Day Basis)
Consumption
Estimated Wastewater
Discharge1
Year
Water Withdrawal
From Catawba
Basin Catawba
River Basin
Rocky
River Basin
Catawba
River Basin
Rocky
River Basin
Total Return to
Catawba River
Subbasin2 IBT
2000 152.9 30.2 5.1 108.7 8.9 138.9 14.0
2010 184.3 34.4 8.1 126.5 15.2 161.0 23.3
2020 213.9 38.2 11.3 146.2 18.3 184.3 29.5
2030 239.4 42.2 13.1 164.4 19.7 206.6 32.8
Note:
1 Estimated wastewater discharge represents the amount of water withdrawal that is discharged as wastewater.
It does not include the impacts of inflow and infiltration on actual wastewater discharge amounts.
2 Total Return to Catawba River Subbasin = Catawba River Consumption + Catawba River Wastewater
Discharge
3 Interbasin Transfer = Water Withdrawal from Catawba – Total Return to Catawba
In order to allow some contingency for uncertainty in projected population growth or water
demands, the requested IBT is 33 mgd, based on a calculated amount of 32.8 mgd. The IBT
calculation is based on projected growth through 2030 and existing wastewater treatment
facilities in the receiving basin. As indicated previously, this IBT does not include transfers
associated with water or wastewater service provided to the Goose Creek watershed in
Mecklenburg County.
3.2 Alternatives to the Proposed IBT
Alternatives to the proposed interbasin transfer are discussed below. The three alternatives
considered are:
1. No action
2. Obtain water from the Rocky River Subbasin
3. Discharge water to the Catawba River Subbasin
Table 3-4 summarizes maximum day water use, wastewater discharge, and interbasin
transfer amounts for the proposed and alternative scenarios in 2030. These estimates do not
include future growth in the Goose Creek watershed. Each alternative is assumed to be
potentially feasible and incorporates consideration of physical and environmental
constraints based on current available information.
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TABLE 3-4Maximum Day Water Use, Discharge, and Interbasin Transfer (mgd) for CMUD Alternatives in 2030
Alternative
Catawba Water
Use
Rocky River
Water Use
Catawba WW
Discharge 1 Rocky River
WW Discharge 1 Interbasin
Transfer 2
Proposed
Action
240 0 165 20 33
No Action 223 0 165 9 16
Obtain Water
from Rocky
River
223 17 165 20 16
Increase
Discharge to
Catawba
240 0 182 3 16
Note:
1 Discharge represents the portion of the water used that is discharged to the wastewater system, and is not
necessarily the same as actual WWTP discharges.
2 Interbasin Transfer includes a consumptive use portion in the receiving basin.
3.2.1 No Action Alternative
Under the no action alternative, CMUD will not provide additional water/sewer services or
increase bulk water sales to customers within the Rocky River Subbasin. Therefore, as
shown in Table 3-4, CMUD’s water use and wastewater discharge would decrease
compared to the proposed IBT. The no action alternative would cost less, but revenue from
water sales would also decrease. Though development in the area might be limited because
of the lack of centralized water/sewer service, it is probable that growth will still occur that
could be serviced by individual wells and on-site wastewater systems. Community water
systems and package sewer plants could also allow growth. This sustained proliferation of
septic tanks and small package plants will pose a detriment to water quality in many area
streams. Septic tank failure can cross-contaminate groundwater. Bacterial contamination
from septic tank effluent has been found to be a common occurrence in suburban and rural
areas served by groundwater because the subsurface water is being used both as a source of
drinking water and as a disposal medium for wastewater.
3.2.2 Obtain Water from Rocky River Subbasin Alternative
One option for CMUD is to develop a water supply source in the Rocky River Subbasin so
that the interbasin transfer amount does not increase from the grandfathered amount of 16.1
mgd. This would require development of a water source to supply 17 mgd on an average
annual basis. The site considered for this analysis is just upstream of the RRR WWTP with a
drainage area of approximately 100 square miles. Planning level costs for constructing a
similar-sized reservoir, the Little River Reservoir in Wake County, to supply 18 mgd are
estimated to be about $54 million. If this cost was prorated for the 17 mgd Rocky River
Reservoir, the total cost for a Rocky River Reservoir could be expected to be about $51
million (reservoir only, pumping and transmission costs depend upon length of pipeline).
The Rocky River and its tributaries are not classified as water supply waters, so water
supply watershed protection measures are not in place and there are numerous point source
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discharges upstream of the potential reservoir site. Development of a new WTP would be
more expensive than expanding the existing WTPs in the Catawba River Subbasin, and
treatment costs would be higher since the Catawba River lakes are very high quality and are
protected as water supply sources. The regulatory requirements for developing this source
would be substantial.
Proposals for development of new impoundments for water supply in rapidly urbanizing
watersheds have faced significant regulatory requirements and created considerable public
controversy. The Randleman Lake project in the Deep River portion of the Cape Fear River
Basin has faced significant regulatory and public hurdles. Concerns have focused around
adequate protection of public health with an urban/urbanizing watershed to loss of rural
land. These issues are exacerbated by the fact that this area has never been identified as a
potential water supply watershed and there has been no effort to protect the watershed for
this purpose. In contrast, the Little River Watershed in Wake County (mentioned above) has
been protected through local ordinances and state stream classification as a water supply
source since the mid-1980s. The Little River reservoir is not planned to be developed until
after 2010.
3.2.3 Discharge Water to Catawba River Subbasin Alternative
For comparison purposes it is assumed that CMUD would substantially expand the
McAlpine WWTP as an alternative to using WWTPs in the receiving basin, and a new
regional facility is not constructed in the Rocky River. WWTP expansion costs would be
about the same and perhaps more expensive due to the many generations of existing
facilities at McAlpine WWTP. Transmission and pump station costs for 17 mgd (estimated
required maximum month capacity under this alternative) would be about $10.5 million. SC
DHEC has expressed concerns with DENR about nutrient levels in the Catawba
Basinspecifically the levels of phosphorus from dischargers in the Sugar Creek Basin.
Recently, SC DHEC has administratively appealed National Pollutant Discharge
Elimination System (NPDES) permits issued for the McAlpine, Sugar and Irwin WWTPs
because of concerns regarding phosphorus. Proceedings of this appeal are on-going.
3.2.7 Conclusions of Alternatives Analysis
All of the considered alternatives will result in significant environmental impacts. The
proposed IBT is considered the most feasible alternative.
3.3 Present and Future Impacts on Catawba River Subbasin
(Source Basin)
This section summarizes the findings of the EA regarding the present and future impacts
within the Catawba River Subbasin on the following:
• Water supply needs of municipalities, industries, and the agricultural sector
• Wastewater assimilation
• Water quality
• Fish and wildlife
• Navigation
• Recreation
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3.3.1 Water Supply
Duke Power has stated that, as CMUD’s withdrawals and IBTs increase, they expect to
operate the reservoirs of the Catawba-Wateree Project within the same elevation ranges that
they have been historically operated within. This limits the potential impacts of the
proposed increase in IBT to the cumulative reservoir outflows and power generation.
The results of reservoir operations modeling indicate that CMUD water withdrawals would
not substantially affect average pool elevations or magnitude of water level fluctuations in
any of the Catawba-Wateree Project reservoirs, even during drought conditions. The largest
potential effect is on Lake Wylie since water withdrawals occur upstream of Lake Wylie and
the majority of return wastewater flows come back into the Catawba River through Sugar
Creek, downstream of the Lake Wylie dam. Since the total CMUD withdrawal is projected
to not have a significant effect, the reduction resulting from IBT is also insignificant.
During a drought situation CMUD would be following its Water Shortage Response Plan,
which includes either voluntary or mandatory conservation measures depending on the
severity of the drought. The results of the evaluations previously discussed do not consider
conservation measures customarily implemented in a drought period which tend to reduce
water use rates below the average. Therefore, the expected impacts on lake surface
elevations and cumulative reservoir outflows during a drought would be less severe than
those previously presented.
The proposed transfer amount of 33 mgd (maximum day) represents 13 percent of CMUD’s
future maximum day water use. Therefore, the potential cumulative impact of the proposed
water transfer on the Catawba-Wateree lake system is considered minor. The proposed
transfer will not result in significant adverse impacts related with water availability for
other existing and future users of water in the source basin.
There are no secondary impacts on water supply related to growth due to the transfer of
water from the source basin. There are no significant cumulative impacts in the source basin
directly related to the transfer of water.
3.3.2 Wastewater Assimilation
There are no expected significant direct impacts in the wastewater assimilation capacity in
the source basin as the result of the transfer of water from Mountain Island Lake. The
hydrology of the system will not be affected in any major manner due to the proposed
transfer. Therefore, the assimilative capacity of the surface waters in the source basin is not
expected to change due to the proposed transfer of water. In addition, DWQ discourages
lake dischargers.
There are no secondary impacts on water quality related to growth due to the transfer of
water from the source basin. There are no significant cumulative impacts in the source basin
directly related to the transfer of water.
3.3.3 Water Quality
Direct impacts in the water quality of surface waters in the source basin are not expected
because there will not be any major changes in the hydrology of the system due to the
increased withdrawal. Since the hydrology of the system will not be affected in any major
manner due to the proposed transfer, water quality is not expected to be affected in Lake
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Norman, Mountain Island Lake, Lake Wylie, nor in the other surface waters of the study
area in the source basin.
As previously mentioned, there are no secondary impacts on water quality related to
growth due to the transfer of water from the source basin. There are no significant
cumulative impacts in the source basin directly related to the transfer of water.
3.3.4 Fish and Wildlife Resources
As discussed in Section 3.3.1, an analysis conducted by Duke Power under normal and
drought conditions has indicated that there will be no changes in the surface water
elevations of Lake Norman, Mountain Island Lake, or Lake Wylie due to the proposed IBT.
The FERC application for the additional withdrawal from Mountain Island Lake as part of
this IBT concluded that changes in Catawba River flow and lake elevations due to the
increase in average annual withdrawals would be insignificant (CMUD, 1999). No
significant changes to river flows, lake elevations, or system hydrology will occur in the
three lakes.
Therefore, the IBT is not expected to significantly impact fish, wildlife, or aquatic species in
the source basin. Only under more pronounced drought conditions will the surface water
elevations upstream of the Mountain Island Dam decrease moderately; however, this
moderate effect is not anticipated to be significant in terms of impacts on wildlife or aquatic
resources in the source basin.
As discussed in the FERC application for the increased withdrawal from Mountain Island
Lake associated with the IBT (subject to a separate EA), there has been some wildlife
concerns in the past regarding fishery resources being subject to entrainment and
impingement on intake screens. The concern is that resident fish eggs not attached to rock
substrata or vegetation would float with the currents and be susceptible to entrainment. In
addition, larval fish have only limited swimming abilities, and larval fish emerging along
the reservoir shoreline in the proximity of the intake may be subject to entrainment also. The
FERC application concludes that during normal operations, water will be withdrawn from
the lake through a combination of four cells, up to the maximum requested rate of 330 mgd,
at intake velocities below 0.5 feet per second (fps), which is the maximum velocity preferred
by NC Wildlife Resources. The FERC application concludes that even under drought
conditions, the approach velocities for all four cells will be below 0.5 fps (CMUD, 1999). The
increase in maximum water withdrawal rate requested in the current application would not
change the protective level of the intake in Mountain Island reservoir for fisheries resources.
This is because the design of the intake and traveling screens was based on the maximum
withdrawals now being requested. Design velocities would always be less than 0.5 feet per
second, which is below the swimming velocity of most fish (EPRI, 1986), and is below North
Carolina and U.S. Fish and Wildlife Service (USFWS) guidelines for maximum approach
velocities
The proposed IBT does not require the construction of additional water intake structures in
Mountain Island Lake. Any proposed pumping stations and conveyance lines associated
with implementing the transfer will be permitted separately under appropriate state and
federal programs and their fish, wildlife, and sensitive species impacts evaluated under a
separate NCEPA or NEPA process.
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc 3-8
With no significant changes to lake elevation, lake and basin hydrology, or water quality in
the source basin, the IBT project will not have any significant direct impact on fish, aquatic,
wildlife, or sensitive resources within the source basin. No secondary impacts are expected.
3.3.5 Navigation
No direct or indirect impacts of the proposed IBT on navigation in the receiving basin are
expected.
3.3.6 Recreation
The IBT will not significantly alter the availability of water to the source basin to serve
existing and projected land uses in the source basin. The IBT will not, when considered with
other water withdrawal projected from the reservoir system, cause significant cumulative
elevation changes in any of the project lakes, nor will water quality in any of the water
bodies change substantially. Minimum releases of water from the various reservoirs in the
chain will not change, even under severe drought conditions. No land uses, public areas, or
recreational sites will be flooded or drained with the transfer. The project will therefore not
change the existing recreational use in the source basin.
3.3.7 Hydroelectric Power Generation
Direct impacts of the proposed interbasin transfer on hydroelectric power generation in the
Catawba River subbasin are not expected to be significant. The proposed interbasin transfer
of 33 mgd (maximum day) in 2030 represents approximately 13% of the CMUD’s maximum
day demand in 2030. Therefore, any potential impact on hydroelectric power generation is
due to increased water withdrawals and not on the interbasin transfer. On behalf of CMUD,
Duke Power is requesting from the FERC an increase in the permitted water withdrawals
from Mountain Island Lake from 165 mgd to 330 mgd (instantaneous maximum). This
increase will allow CMUD to meet projected demands through 2030 in Mecklenburg
County. Duke Power has stated that, as CMUD’s withdrawals and interbasin transfers
increase, they expect to operate the reservoirs of the Catawba-Wateree Project within the
same elevation ranges that they have been historically operated within. This limits the
potential impacts of the proposed increase in withdrawal to the cumulative reservoir
outflows and power generation. The IBT contribution to these potential impacts is minor.
3.4 Present and Future Impacts on the Rocky River Subbasin
(Receiving Basin)
This section summarizes the findings of the EA regarding the present and future impacts
within the Rocky River Subbasin on the following:
• Water quality
• Wastewater assimilation
• Fish and wildlife
• Navigation
• Recreation
• Flooding
A summary of measures to mitigate adverse impacts is included in Appendix C.
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc 3-9
3.4.1 Water Quality
Based on consultations with U.S. Geological Service (USGS), DWQ, and DWR, the
additional flow in the receiving basin will result in a total stream flow of approximately 47
cfs in the Rocky River (below the confluence with Crooked Creek) under 7Q10 flow
conditions. Current 7Q10 stream flow at this point of the Rocky River is estimated to be 21
cfs. The additional flow will bring the stream flow in the Rocky River closer to desirable
stream flows designed to maintain aquatic habitat. Based on a regression equation
developed by DWR to determine the minimum flow for a stream in the Piedmont which
exhibits moderate aquatic habitat, and for which no continuous gage record exists, the
recommended minimum stream flow to maintain aquatic habitat in the Rocky River (below
Crooked Creek) is 58 cfs. According to guidance provided by DWR and consultations with
Mr. Mead of DWR, the Rocky River near Crooked Creek is considered within the Piedmont
region for application of the equation. Cursory visual inspection of this section of the Rocky
River by CH2M HILL staff indicated that the stream provides moderate aquatic habitat.
The ratio of the additional wastewater (26 cfs) to the drainage area of the Rocky River (683
square miles), below Crooked Creek, is less than 0.4. DWR has asserted, based on studies
conducted in Piedmont streams (DWR, 1987), that floodwater carrying capacity, streambank
erosion, and fish habitat need not be considered in detail for NCEPA documentation or for
NPDES permit decisions when the aforementioned ratio is less than 0.40.
Direct impacts related to water quality and streambank erosion due to an increase in stream
flow are not expected to be significant. Additional growth and development in the receiving
basin may impact water quality, stormwater runoff, frequency and intensity of flooding,
and land use. Mitigation measures for secondary impacts related to growth and
development are presented in Appendix C.
3.4.2 Wastewater Assimilation
Primary impacts to water quality from the IBT originate from the operation of wastewater
treatment facilities. However, these facilities have been already permitted and the IBT will
not result in additional permitted capacities. Existing NPDES permits were issued to
protect instream water quality. The permitting process for each of these facilities has
complied with the NCEPA requirements. DWQ’s antidegradation policy requires that only
the alternative that causes the least amount of environmental damage can be permitted
under the NPDES program. Additional growth and development in the receiving basin may
impact water quality, stormwater runoff, frequency and intensity of flooding, and land use.
Mitigation measures for secondary impacts related to growth and development are
presented in Appendix C.
3.4.3 Fish and Wildlife Resources
The IBT itself will not have any direct impacts on natural communities, Significant Natural
Habitat Areas (SNHAs), fisheries, or sensitive species and their habitats in the receiving
basin since no construction is planned with the IBT.
However, there may be secondary impacts on fish and wildlife resources through increased
growth and development, which may be facilitated by the proposed IBT. Additional
growth and development in the receiving basin may impact water quality, stormwater
runoff, frequency and intensity of flooding, and land use. Mitigation measures for
secondary impacts related to growth and development are presented in Appendix C.
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc 3-10
3.4.5 Navigation
No direct or indirect impacts of the proposed IBT on navigation in the Rocky River Subbasin
are expected since streamflows in the Rocky River Subbasin are not expected to change
significantly. No expansion of existing WWTPs or construction of new WWTPs is planned
within the receiving basin.
3.4.6 Recreation
The proposed IBT will not have any direct or indirect impacts on recreation in the Rocky
River Subbasin. Increased wastewater as a result of the proposed IBT will be within existing
permit limits and will not significantly affect recreational resources along the receiving
stream corridors. No recreational lands will be subject to additional threats of flooding as a
direct result of the proposed IBT.
3.4.7 Flooding
Direct impacts related to flooding due to an increase in stream flow are not expected to be
significant. Again, the permitted NPDES flows will handle the proposed IBT flow amounts.
Average annual stream flow in the Rocky River, downstream from Crooked Creek, is
expected to increase from 663 cfs to approximately 690 cfs at permitted flows, or about 4
percent. The expected increase is minor and well within the historical stream flow
variability based on a flow duration analysis conducted in conjunction with the Raleigh
Office of USGS. For this analysis, stream flow variability for the Rocky River below Crooked
Creek is assumed to be similar to that at the Norwood gage station. The analysis estimated
that flows in the Rocky River, below Crooked Creek, historically exceed 690 cfs twenty
percent of the time and 1,500 cfs ten percent of the time. The one-year flow event in the
Rocky River was estimated at about 6,000 cfs; therefore, the potential flow increase is less
than 0.5 percent of the one-year flow event. The proposed IBT will not have any direct
impacts on flooding in the Rocky River Subbasin. Increased wastewater discharges into as a
result of the proposed IBT will be within existing permit limits and will not significantly
affect streamflows and flooding along the receiving stream corridors.
However, there may be secondary impacts within the receiving basin related to growth and
development which may potentially increase both stormwater runoff from construction
activities and impervious surface area and result in a higher risk if flooding. A summary of
measures to mitigate adverse impacts is included in Appendix C.
3.5 Other Considerations
3.5.1 Regional Water Supplier
CMUD currently provides and plans to continue to provide the City of Charlotte and the six
other towns in Mecklenburg County with finished drinking water. Therefore, CMUD is a
regional water supplier.
3.5.2 Reuse and Water Conservation
In an effort to minimize discharges to surface waters, decrease use of potable water (thereby
reducing the need for transferring water across basin boundaries), reduce peak demand for
potable water, and use treated wastewater as a valuable resource, CMUD has been
aggressively pursuing opportunities for water reuse. At their Mallard Creek water
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc 3-11
reclamation facility (WRF), CMUD is permitted to reuse up to 3 mgd of reclaimed water
(treated wastewater) for irrigation purposes. This was the first facility permitted for
conjunctive use (i.e., both discharge and reuse) of reclaimed water under the revised rules
for water reclamation developed by the DWQ in 1996. CMUD is continuing to promote
opportunities for reuse in the IBT project area by proposing to construct the Three-County
WRF with a substantial portion of the effluent reused rather than discharged into the Rocky
River.
In 1986, the Charlotte City Council granted authority for the City Manager to invoke
mandatory water conservation, and CMUD developed a Water Shortage-Drought-
Emergency Response Plan. The plan consists of voluntary and mandatory procedures,
which are instituted when finished water demands approach supply, treatment, or
distribution capacities for five (voluntary procedures) or ten (mandatory procedures)
consecutive days with no weather breaks predicted. According to DWR, voluntary and
mandatory measures can be expected to reduce water use by 5 to 15 percent and 15 to 30
percent, respectively.
The voluntary conservation procedure requests that non-essential watering be conducted by
residents only on an odd or even day of the week, which corresponds to the house number.
A six-step process is implemented to notify Mecklenburg County citizens of the voluntary
conservation procedure that should be followed, and a brochure with additional water
conservation tips is to be distributed. The Water Distribution Division will also begin
working water system priority leaks within 48 hours and emergency leaks immediately.
When CMUD recognizes that conditions requiring mandatory conservation procedures
exist, a Notice of Declared Water Distribution Crisis must be posted by the City Manager 12
hours in advance of the mandatory measures taking effect. The mandatory conservation
procedures include a system-wide ban on non-essential irrigation (excluding that essential
to businesses, golf courses, greenhouses, etc.). The same notification procedure applies;
however, violations will be issued for non-compliance. The first violation within 24 hours
will result in a warning, and the second violation will result in a penalty.
CMUD is currently taking the following measures to reduce water consumption rates:
• There are conservation rates in effect which dictate that high water use results in higher
cost as opposed to giving preference to high quantity residential and commercial users.
• A major element of CMUD’s water conservation efforts will be wastewater reclamation.
A project is currently underway to reclaim water at Mallard Creek WWTP.
• CMUD has developed an extensive public education and information program,
including Water Watch, which was developed to keep customers informed about water
demands and the utility’s capacity to deliver finished water throughout the distribution
system without adverse impacts to system pressures
The strategy behind CMUD’s efforts is to focus on incentives and public education rather
than on ordinances.
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc 4-1
SECTION 4
Compliance and Monitoring Plan
The proposed compliance and monitoring plan for the requested CMUD IBT certificate
includes the following elements, which are described in the sections below:
1. IBT Calculation
2. Reporting
The details of monitoring and compliance will be specified in a Compliance and Monitoring
Plan approved by DWR.
4.1 IBT Calculation
CMUD will calculate the daily IBT using a methodology developed in conjunction with
DWR staff. The methodology is based on the guidance developed by DWR for estimating
IBT amounts as part of the Local Water Supply Planning process. Table 4-1 provides an
example of the calculations that will be submitted.
Consumptive use for each day is assumed to be the difference between total water use and
total wastewater discharged, or zero if discharge is greater than potable water use. This may
underestimate consumptive use in the winter months (when water use is typically lower
than wastewater discharge), but the effect will be to slightly overestimate the resulting IBT
amount. When discharge is greater than water use, the portion of raw water withdrawal
that is discharged as wastewater in each basin is assumed to be proportional to the actual
wastewater discharges in that basin. In effect, this is assuming that the same degree of
inflow and infiltration occurs in the sewer system in each basin. These assumptions will not
impact evaluation of compliance with the requested IBT certificate, since the maximum IBT
is expected to occur in the summer.
The portion of consumptive use that occurs in the source basin will be estimated as the
portion of the water service area in the source basin, and will be updated annually to reflect
changes in the development of the service area.
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc 4-2
TABLE 4-1
Sample Daily Calculations for Interbasin Transfer1
Consumptive Use
(mgd)
Wastewater
Discharged (mgd)
Date
Withdrawal
from
Catawba
Basin
(mgd)
Catawba
Basin
Rocky
River
Basin
Catawba
Basin
Rocky
River
Basin
Total Return
to Catawba
Basin
(mgd)
Interbasin
Transfer
(mgd)
IBT as % of
Grandfathered
Amount2
6/1 139.31 57.69 9.39 68.33 3.90 126.02 13.29 83%
6/2 150.65 66.04 10.75 70.35 3.50 136.39 14.25 89%
6/3 149.97 67.48 10.99 66.80 4.70 134.28 15.69 97%
6/4 110.61 32.50 5.29 68.72 4.10 101.22 9.39 58%
6/5 108.20 30.80 5.01 68.09 4.30 98.89 9.31 58%
6/6 104.81 22.28 3.63 74.48 4.42 96.76 8.05 50%
6/7 117.78 33.11 5.39 75.68 3.60 108.79 8.99 56%
6/8 122.77 40.52 6.60 71.45 4.20 111.97 10.80 67%
6/9 133.63 52.07 8.48 68.18 4.90 120.25 13.38 83%
6/10 142.47 60.23 9.80 67.34 5.10 127.57 14.90 93%
6/11 141.19 63.70 10.37 63.62 3.50 127.32 13.87 86%
6/12 144.77 68.49 11.15 60.53 4.60 129.02 15.75 98%
6/13 137.82 53.29 8.68 71.05 4.80 124.34 13.48 84%
6/14 135.65 49.45 8.05 74.95 3.20 124.40 11.25 70%
6/15 120.06 36.28 5.91 72.67 5.20 108.95 11.11 69%
6/16 123.38 42.51 6.92 68.24 5.70 110.75 12.62 78%
6/17 126.49 46.78 7.61 67.10 5.00 113.88 12.61 78%
6/18 126.76 48.79 7.94 64.83 5.20 113.62 13.14 82%
6/19 124.87 41.24 6.71 71.21 5.70 112.45 12.41 77%
6/20 124.43 43.90 7.15 67.88 5.50 111.78 12.65 79%
6/21 135.60 54.00 8.79 67.91 4.90 121.91 13.69 85%
6/22 134.81 51.81 8.43 68.87 5.70 120.68 14.13 88%
6/23 141.49 58.97 9.60 67.52 5.40 126.49 15.00 93%
6/24 142.61 61.75 10.05 65.20 5.60 126.95 15.65 97%
6/25 135.05 57.41 9.35 62.60 5.70 120.01 15.05 93%
6/26 142.37 60.52 9.85 66.29 5.70 126.81 15.55 97%
6/27 129.63 45.49 7.40 71.14 5.60 116.63 13.00 81%
6/28 120.53 35.80 5.83 72.70 6.20 108.50 12.03 75%
6/29 110.51 24.46 3.98 76.37 5.70 100.83 9.68 60%
6/30 111.10 28.33 4.61 72.86 5.30 101.19 9.91 62%
Minimum 8.05 50%
Maximum 15.75 98%
Average 129.64 47.86 7.79 69.10 4.90 116.95 12.69 79%
1. from June 2000
2. Percentage of daily IBT to permitted amount under grandfathered IBT of 16.1 mgd.
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc 4-3
4.2 Reporting
At the end of each calendar year, the daily IBT calculations will be summarized in an annual
report to DWR. The annual report will document the maximum day IBT amount for that
year. The distribution of consumptive uses between the source and receiving basins will be
reviewed and modified to reflect changes in the development of the service area. The
Annual Report will also document compliance with any conditions, if applicable, that the
EMC includes in the IBT certificate.
Once an annual report indicates that a daily maximumIBT has exceeded 80% of theIBT
specified in the certificate, CMUD will begin monthly reporting to DWR during the next
calendar year. At the end of each month, CMUD will report IBT calculations and document
the maximum IBT that occurred during that month. CMUD will also continue to submit
annual reports that review the distribution of consumptive uses between the source and
receiving basins based on service area development in the previous year, and document
compliance with any interbasin certificate conditions, if applicable.
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc 5-1
SECTION 5
Drought Management Plan
Lake Norman and Mountain Island Lake are part of the Catawba River Basin and are part of
eleven hydropower impoundments in the Catawba-Wateree Project. The impoundments
are owned and managed by Duke Power under license from the FERC. Lake levels are
managed to provide for power generation, flood control, water supply (for CMUD), and
secondarily to provide recreational opportunities. Duke Power manages the lake levels
according to the “target levels” in Table 5-1, which are presented as a percentage of the
normal (full) pool elevation. The normal pool elevation for Lake Norman is 760 feet msl and
its maximum drawdown is 15 feet. The normal pool elevation for Mountain Island Lake is
647.5 feet msl and its maximum drawdown is 10 feet. The maximum drawdown for each
lake represents the minimum lake level required by Duke Power for power generation.
TABLE 5-1
Target Level for Lake Norman and Mountain Island Lake1
Month Target Operating Range for
Lake Norman
Target Operating Range for
Mountain Island Lake
January 94 - 96% 96%
February 92 - 94% 96%
March 92 - 94% 96%
April 94 - 96% 96%
May 96 - 98% 96%
June 98% 96%
July 98% 96%
August 98% 96%
September – November 97 - 98% 96%
December 96 - 97% 96%
Note:
1 Target operating range is presented as a percentage of normal (full) pool.
Duke Power owns and manages four surface water impoundments upstream of Lake
Norman and Mountain Island Lake including Lake James, Lake Rhodhiss, Lake Hickory,
and Lookout Shoals Lake.
During drought conditions, Duke Power can release some storage in these upstream
impoundments to ensure adequate water supply in Lake Norman and Mountain Island
Lake and to maintain minimum downstream flows. This was the case during the severe
drought of 1999 and 2000 when flows in the Catawba River exceeded the minimum release
from Lake Wylie of 411 cfs required by Duke’s FERC license. The minimum downstream
flows for the impoundments in the Duke Catawba-Wateree Project are presented in Table 5-
2.
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc 5-2
TABLE 5-2
Minimum Flow Requirements for Duke’s Catawba Wateree Project
Development
(Reservoir)
Minimum
Continuous Flow
(cfs)
Minimum
Average Daily Flow
(cfs)
Lake James 25 66
Lake Rhodhiss 40 225
Lake Hickory 40 261
Lookout Shoals Lake 60 278
Lake Norman 80 311
Mountain Island Lake 80 314
Lake Wylie - 411
Fishing Creek Lake - 440
Great Falls Lake - 444
Rocky Creek Lake - 445
Lake Wateree - 446
Currently, CMUD does not have an adopted drought management plan. CMUD is in the
process of completing a Water Conservation Plan. Development of a drought management
plan would require the cooperation of Duke Power since CMUD’s water supplies are only
two of eleven impoundments managed by Duke Power. Due to the complexity of the
Catawba-Wateree system, Duke Power uses a reservoir operations model, a proprietary
version of the commercially available CHEOPS (Computer Hydro-Electric Operations and
Planning Model Software) model, to manage the lakes.
The model was calibrated specifically for the Catawba-Wateree Hydroelectric Project by
Duke using detailed engineering and operations data for the project and historical flow
records from available flow gauges in the basin. The Catawba-Wateree operations model
accounts for inflows (streamflows) and outflows (withdrawals, generation, and indirectly,
evaporation) for each reservoir in the project. The model contains detailed data for storage-
area-volume relationships, reservoir elevation constraints, operating rules, turbine and
generator efficiency curves, travel times and paths.
The complexity of the operation and management of the Catawba-Wateree Project do not
allow for a simple monitoring of CMUD’s available raw water supply capacity.
Cooperation by Duke Power would be needed in order to implement an effective drought
management plan.
However, CMUD has developed the Water Watch Index to provide customers with a
measure of the water supply capacity. The Water Watch Index is updated daily based on
water demands and the delivery capacity of the distribution system. Therefore, the index
was developed to primarily to keep customers informed about water demands and the
utility’s capacity to deliver finished water throughout the distribution system without
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc 5-3
adverse impacts to system pressures rather than a measure of raw water supply capacity.
The Water Watch Index includes the following alert levels:
• STABLE: Demand for water is manageable. Thanks for your conservation
• SERIOUS: Water use is very high. Please minimize nonessential water use
• CRITICAL: Water use is too high. Eliminate nonessential water use
• MANDATORY: Mandatory water restrictions are in effect and will be enforced.
Water Watch Index for Friday June 22, 2001
Mandatory conservation measures could be instituted if the water supply situation becomes
critical. Depending on the severity of the problem, mandatory restrictions could limit or
forbid lawn watering, car washing, filling swimming pools or other specified non-essential
outdoor use during certain days and times. Those who violate a City water conservation
ordinance would receive a fine for each recorded event/offense. Depending on the severity
of the problem, landscapers and some other businesses that rely on water may be allowed to
continue operation under certain circumstances. The first and only time that mandatory
conservation restrictions ever issued was in 1986.
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc 6-1
SECTION 6
References
Charlotte-Mecklenburg Utilities Department (CMUD). 1999. FERC Application for Increase in
Withdrawal Rate from Mountain Island Lake. Prepared by CH2MHILL.
CH2M HILL. 2001. Environmental Assessment for Charlotte-Mecklenburg Utilities for Increase in
Interbasin Transfer from the Catawba River Subbasin to the Rocky River Subbasin. Raleigh,
North Carolina.
EPRI (Electric Power Research Institute). 1986. Assessment of Downstream Migrant Fish
Protection Technologies for Hydropower Application. Palo Alto, California.
North Carolina Division of Water Resources (DWR). 1987. Potential Effects of Proposed Wastewater
Discharges to Middle Creek on Flooding, Streambank Erosion, and Fish Habitat. Raleigh,
NC.
North Carolina Office of State Planning. 1999. County Growth Projections – 2010 – 2020. Web site:
http://www.ospl.state.nc.us/demog/projbdm1.html
South Carolina Department of Health and Environmental Control (SC DHEC), 1996. Watershed
Water Quality Management Strategy: Catawba-Santee Basin. Technical Report No. 002-96.
Columbia, SC
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc A-1
APPENDIX A
Finding of No Significant Impact (FONSI)
C(~$.t 10-01,",01
FINAL
MITIGA TED FINDING OF NO SIGNIFICANT IMP ACT
CHARLOTTE- MECKLENB URG uTILmEs
PROPOSED INCREASE IN INTERBASIN TRANSFER
FROM THE CAT A WBA RIVER BASIN TO THE ROCKY RIVER BASIN
RESPONSIBLE AGENCY: NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
CONT ACT:TOM FRANSEN
DIVISION OF W A TER RESOURCES
1611 MAIL SERVICE CENTER
RALEIGH, NORTH CAROLINA 27699-1611
[phone]
August 20,2001
MITIGA TED FINDING OF NO SIGNIFICANT IMPACT (FONSI)
Project Applicant: Charlotte-Mecklenburg Utilities
Summary Project Description: Charlotte Mecklenburg Utilities (CMUD) is requesting
an interbasin transfer (IBT) certificate from the North Carolina Environmental
Management Commission (EMC) for an increase in their transfer amount from 16.1
million gallons per day (mgd) to 35 mgd. The proposed IBT is based on the e-xisting
water withdrawals from the source basin (Mountain Island Lake within the Catawba
River Sub-basin, and transfer of the water to the receiving basin (Eastern Mecklenburg
County within the Rocky River Sub-basin via consumptive use and existing discharges in
the receiving basin (Mallard Creek Wastewater Treatment Plant [WWTP] and Rocky
River Regional WWTP). The IBT will not lead to expansions of permitted discharges at
either of the WWTP locations in the receiving basin. This Environmental Assessment
(EA) provides supporting documentation for the IBT certificate petition.
Background and Procedural History: Pursuant to the Regulation of Surface Water
Transfers Act [G.S. 143-2l5.22I(fl)], the Department is required to prepare an
environmental assessment (EA) for petitions for an interbasin transfer certificate. The
detemlination of whether an environmental impact statement shall also be required is
made in accordance with provisions of Article 1 ofG.S. 113A. Within the Department,
the Division of Water Resources is the responsible agency for interbasin transfer
requests.
After reviewing scoping comments, the Division determined that a mitigated EA was the
appropriate environmental review document. Under a mitigated EA, all significant
impacts must be mitigated to a level of insignificance through identified mitigation
measures. The Division will recommend to the EMC that some of the mitigation
measures be included in the certificate as enforceable permit conditions.
Following public review of the FONSI/EA, the Applicant will present its petition .
requesting an increase in interbasin transfer to the EMC. The Division will also present
its recommendations. The EMC will then hold a public hearing on the proposed transfer.
A final decision will be made at the next full EMC meeting following the public
comment period and preparation of a hearing officer's report.
The environmental assessment (EA) found no direct impacts that would result from the
proposed transfer. Direct impacts that may result from future infrastructure projects such
as water and sewer lines will be assessed through separate environmental reviews of
those projects. The EA identified secondary and cumulative impacts due to growth in the
receiving basin as the primary significant environmental impacts. These impacts include
water quality impacts, wetland impacts, impacts to threatened mussel populations, habitat
fragmentation, and loss of open space.
Mitigation Measures: The Division of Water Resources will recommend to the EMC
inclusion of a number of conditions in the IBT Certificate for the implementation of long-
term mitigation of secondary and cumulative impacts. The certificate should also include
provisions for a compliance and monitoring plan to track progress on meeting the
proposed conditions. The plan would also specify requirements for reporting actual
.maximum daily transfer amounts. The following items are under consideration for
inclusion in the IBT certificate. Note that the specific permit language may be modified
from the text shown.
Require the County to evaluate the feasibility of each element of the Surface Water
Improvement and Management Program (SWIM) on an annual basis. For those
elements that are deemed feasible, the County should continue to seek funding from
its Board of County Commissioners to fund the SWIM program to continue
implementing the Phases outlined in Section 6.2.1.2 of the EA.
Require the County and the Town of Mint Hill to consider the conclusions ofWRC's
Goose Creek watershed study when complete. Mecklenburg County and Mint Hill
should provide information to WRC on which recommendations they will pursue
adopting and which recommendations are infeasible and why.
.
.Require Mecklenburg County and the City of Charlotte to continue the stakeholder
process to investigate water quantity control from single-farnily development and
water quality control for all development. To accomplish this end, the stakeholder
group should consider evaluating the feasibility of single-farnily detention and
recommending ordinance revisions based on technical, political, long-term
maintenance, cost, and benefits related to the proposed ordinance changes.
In addition to the permit conditions listed above, Mecklenburg County , the City of
Charlotte, and the Towns of Cornelius, Huntersville, Davidson and Mint Hill have
implemented, proposed and lor committed to a number of mitigation measures designed
to avoid and minimize any potentially significant adverse environmental impacts. These
measures include but are not limited to the following:
1
?
3
Mecklenburg County has adopted the Phase I strategy of the Surface Water
Improvement and Management program (SWIM). The goal of the nine-part strategy
is for all county streams to be suitable for prolonged human contact and supportive of
aquatic life.
All towns within Mecklenburg County have adopted stream buffer requirements
under Part 3 of the SWIM Phase I strategy. Buffer widths range from 30 to 100 feet
and apply to all streams with a drainage area of 100 acres or more. Some ofthe local
jurisdictions have adopted more stringent requirements.
Mecklenburg County is implementing water quality modeling under Part 5 of the
SWIM Program strategy. The County is working with the Town of Huntersville to
establish a watershed management strategy for McDowell Creek based on the results
of the model. Following the pilot, the County plans to extend this effort to the entire
county.
2
4.
5
6.
7
8.
9.
Towns within Mecklenburg County have adopted land use policies which include
provisions for open space preservation, stormwater control, sedimentation and
erosion controls, growth boundaries, and tree preservation among others.
The Goose Creek subbasin in Mecklenburg County is removed from the area to be
served by the IBT. A moratorium on the installation of new IBT water lines into
Goose Creek subbasin is in effect until the impacts of additional growth urban growth
on the endangered specifies are fully evaluated.
Mecklenburg County and the Town of Mint Hill commit to participate in the Goose
Creek watershed protection initiative and to cooperate with the NC Wildlife
Resources Commission to secure funding for riparian buffer acquisition in Goose
Creek (particularly within Mecklenburg County).
Mecklenburg County commits to consider incorporation of a number of
recommendations from the Voices and Choices initiative in the county's
environmental protection programs, as appropriate.
Mecklenburg County commits to pursue its existing county-wide comprehensive
watershed management programs and work with Towns on land use planning. This
effort may include working with local land trusts and other natural preservation
groups along with large landowners to implement voluntary forest and agricultural
preservation plans. Mecklenburg County will continue to evaluate the possibility of
using other measures besides typical BMPs to protect sensitive aquatic species,
including land use controls, alternative land use scenarios and land acquisition. Also,
local zoning ordinances could be amended to create zoning districts that prohibit
typical suburban sprawl-type subdivisions, and encourage "smart growth."
Mecklenburg County commits to pursue funding for watershed restoration. This
effort includes working with the North Carolina Wetlands Restoration Program to
identify potential stream restoration sites within Mecklenburg County and using
wetland impact fees generated from projects within Mecklenburg County on county
stream restoration.
Each of the foregoing mitigation measures is described in more detail in the
environmental assessment (EA) supporting the requested interbasin transfer. The
Applicant's proposed mitigation measures have adequately addressed identified concerns
regarding potentially significant adverse environmental impacts. The Division of Water
Resources has determined that the analysis of the potential environmental impacts set
forth in the EA and mitigative measures set forth above support a finding of no
significant impact such that preparation of an environmental impact statement will not be
required. This decision is based upon information in the attached EA an~ review by
governmental agencies. This FONSI completes the environmental review record, which
is available for inspection at the State Clearinghouse.
Thomas C. Fransen
Division of Water Resources
3
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc B-1
APPENDIX B
Resource Agency and Stakeholder Comments
TABLE B-1
Resource Agencies
Resource Agencies Contacted Date of Comment Submittal Concerns Addressed in Letter
(attached)
Section of EA Where
Concerns are
Addressed
Mecklenburg County Department of
Environmental Protection
Phone call: May 3, 1999
Letter dated: November 19, 1999
None. See attached phone record
MCDEP concurs with the EA
findings and mitigation plan
North Carolina Department of
Environment and Natural Resources:
Division of Parks and Recreation
Letter dated: April 30, 1999
Memorandum dated August 16, 1999
Telephone Record dated: September 20, 1999
List of rare species; impacts on
species of concern, secondary
impacts; mitigation plan
3.1.3; 3.2.3; and Sections
4, 5 & 6
North Carolina Department of
Environment and Natural Resources:
Division of Pollution Prevention
Letter dated: May 12, 1999 No concerns submitted
North Carolina Department of
Environment and Natural Resources:
Division Water Quality
Informational documents received
Memorandum dated: August 16, 1999
Telephone Record dated: September 15, 1999
General analysis of secondary
impacts; mitigation plan; project
description; IBT calculations
All sections
North Carolina Department of
Environment and Natural Resources:
Division of Water Resources
Scoping document development
Meeting Summary dated: September 23, 1999
Scoping Document attached All sections
North Carolina Department of
Environment and Natural Resources:
Office of the Secretary
Memorandum dated: August 23, 1999 Forwarded comments from DWQ (8-
16-99), DPR (8-16-99) and WRC (8-
9-99)
All Sections
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc B-2
TABLE B-1
Resource Agencies
Resource Agencies Contacted Date of Comment Submittal Concerns Addressed in Letter
(attached)
Section of EA Where
Concerns are
Addressed
North Carolina Wildlife Resources
Commission
Letter dated: April 23, 1999
Memorandum dated: August 9, 1999
Telephone Record dated: September 14, 1999
Impacts on species of concern,
recreation, and fisheries;
direct/indirect impacts; alternatives;
water conservation; Three-County
facility
2.3; 3.1.2; 3.2.2; 3.1.3;
and Sections 4, 5 & 6
South Carolina Department of Health
and Environmental Control: Bureau of
Water
Letter dated: May 10, 1999
Email dated: June 1, 1999
Lake surface elevations;
downstream flow releases, nutrients
3.1.4; and 5
South Carolina Department of Natural
Resources
Letter dated: May 7, 1999 Printouts of species occurrences 3.1.3
US Department of Interior: Fish and
Wildlife Service
No submittal No concerns submitted. See
attached phone record
US Department of Interior: Fish and
Wildlife Service1 Letter dated: March 12, 1999 Species of concern; Three-County
facility; secondary impacts
2.3; 3.1.3; 3.2.3; and
Sections 4, 5 & 6
North Carolina Department of
Environment and Natural Resources:
Division of Water Quality
Letter dated: May 10, 2000 Letter of concurrence
North Carolina Wildlife Resources
Commission
Letter dated: August 1, 2000 Proposed mitigation Section 6; Response letter
from CMUD dated 12/7/00
in Appendix B
North Carolina Department of
Environment and Natural Resources:
Office of the Secretary
Letter undated: January 29, 2001
(received)
Goose Creek – address secondary
impacts through proposed Three
County WRF and eliminate from this
EA
Goose Creek IBT
removed from EA; IBT
request reduced. All
sections of EA updated.
North Carolina Wildlife Resources
Commission
Letter dated: March 26, 2001 Letter of concurrence
North Carolina Department of
Environment and Natural Resources:
Letter dated: March 30, 2001 Letter of concurrence
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc B-3
TABLE B-1
Resource Agencies
Resource Agencies Contacted Date of Comment Submittal Concerns Addressed in Letter
(attached)
Section of EA Where
Concerns are
Addressed
Division of Parks and Recreation
1 Contacted for the proposed Three-County Water Reclamation Facility project
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc C-1
APPENDIX C
Summary of Local Regulations and Programs
for Mitigation of Adverse Impacts
The IBT certificate request is one of many planned activities that are a response to the rapid
growth in the project area, rather than the cause of such growth. Nevertheless, because such
projects facilitate the urban growth that is occurring, it was determined that the scope of this
EA would include the indirect and cumulative impacts associated with the development
that will be facilitated by the proposed IBT increase. Table C-1 summarizes the local
regulations and programs that will mitigate the potential indirect and cumulative impacts
discussed in Section 3 above. This discussion of the measures to mitigate adverse impacts
can also be found in Section 6 of the EA (CH2M HILL, 2001).
TABLE C-1
Summary of Existing Programs and the Environmental Resources They Protect
Program or
Regulation Wetlands
Land
Use
Fish &
Wildlife
Sensitive
Species
Water
Quality
Air
Quality
Ground
-water Noise Toxics
Sect. 404 XXX X X
Sect. 401 XXX X X
NFIP XXX X X X
WRP XXXX
Archaeological
Protection X
Farmland
Preservation (X) (X)
Stormwater XXXX X
Erosion / sed.XXX X X
SSO Regs.XXX X X X X
CWMTF (X) (X) (X) (X) (X)
Groundwater XXX
Land Conserv.
Incentives (X) (X) (X) (X) (X)
Voices &
Choices (X) (X) (X) (X) (X) (X) (X) (X) (X)
SWIM (X) (X) (X) (X) (X) (X)
Sec 319 (X) (X) (X) (X) (X)
Greenways (X) (X) (X) (X) (X)
Adopt-a-
Stream (X) (X) (X) (X)
Haz. Mitig.XXX X X X
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc C-2
Water
Reclamation XXXX XX
Drought
Management XXX X X X
Cornelius XXXX
Huntersville XXX X X
Davidson (X)
Mint Hill (X)
Note:X = Demonstrates clear environmental benefits, (X) = Shows potential for environmental benefits (program not mandatory/ regulation not yet adopted)
In addition, the following mitigation measures were developed to enhance existing and
proposed environmental protection regulations at the local level. The proposed measures
were developed to complement the existing environmental protection regulatory
framework. The discussion of existing regulatory and non-regulatory mitigation indicates
that there are numerous rules and programs that have been or are being adopted to protect
the natural resources of the study area from the effects of urbanization. This comprehensive
suite of environmental regulations and programs is found to be quite adequate overall in
mitigating the secondary impacts of the proposed action. Therefore, only a limited number
of measures to complement this mitigation are provided. These measures, in combination
with existing and proposed regulations and programs support an overall EA and FONSI
under NCEPA for the project.
Water and Sewer Line EA/EIS Conditions
Subsequent EA and EIS documents for water and sewer conveyance systems in the
receiving basin should contain the following elements to adequately address potentially
significant primary/direct impacts:
1. Locations, types, extent, and importance of wetlands and SNHAs in the water or sewer
line alignment and proposed construction zone and analysis of projected impacts to
wetlands from proposed direct construction impacts.
2. If determined to be necessary, completion of a Wetlands Avoidance and Mitigation Plan
through the formation of a workgroup composed of local, state, and federal government
agencies and the project consultant. This plan should look at local regulatory and non-
regulatory actions that could be taken to supplement existing efforts and adequately
reduce the level of wetland impacts from the project.
3. Since projected land uses for the County were not available in GIS format at this time,
future EA and EIS documents for water and sewer line projects should contain this
information coupled with existing land uses or land cover data for each proposed utility
line project and its service area. This analysis should include a discussion of how the
project complies with local plans and zoning and is consistent with planned land uses
for the area. GIS data coverages of projected land use for Mecklenburg County is
currently in the process of being digitized.
4. Acreage and types of sensitive aquatic or terrestrial species or their habitats that may be
lost or degraded because of construction or operation of the water or sewer line, with
analysis of what can be done to avoid or offset these impacts. Alternative alignments
and utility designs should be proposed to mitigate significant impacts to sensitive
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc C-3
species or habitats. Particular attention should be given to the Crooked Creek
watershed, and suspected locations of other sensitive species that could be impacted by
construction of the utilities.
5. Specific design and operational guidance that will be used to avoid system failures and
toxic spills into surface waters should be provided, with specific attention given to
avoiding sewage releases, sewage overflows and leaks during power outages, storm
events and accidental breaks in the lines, equipment and pump stations. Specific
attention must be given to methods designed for any project activities in proximity to
Crooked Creek and other sensitive habitats identified to reduce the probability for spills
within those sensitive areas.
Enhancing and Strengthening Local Government Regulations & Programs
As shown in Table C-1, the existing programs and regulations in place at the federal, state
and local levels mitigate to a great extent the impacts of land use on water quality, wetlands,
sensitive aquatic and terrestrial species, and fish and wildlife habitat. In addition, our
evaluation shows an exceptionally strong commitment from Mecklenburg County to
address many of the significant environmental impacts predicted from urbanization of the
project area. Section 6.3 of the EA describes the commitment made by Mecklenburg County
in addressing secondary impacts of the IBT. Table C-2 provides a summary of the
monitoring plan for implementing proposed additional mitigation efforts committed by
Mecklenburg County.
C:\Documents\Projects\CMUD\CMUD_IBT Petition_final.doc C-4
TABLE C-2
Mitigation Monitoring Plan
Mitigation
Measure Implementation Timing of Action
Lead Agency
Responsible
for
Completing
Measure
Agency to
Monitor
and
Enforce
Consider
adopting a
number of Voices
and Choices
recommendations
at the local level,
as appropriate
Mecklenburg County’s Board of
Commissioners holds a session to
hear presentations from the County
staff who where a part of the Voices
and Choices process. Board of
Commissioners recommends
feasibility analysis for the
implementation of a number of
recommendations.
Status: Proposed
Board of
Commissioner’s
session and
feasibility analysis
recommendation
may occur after
Voices and Choices
meetings in March
2001
Mecklenburg
County
NC
Division of
Water
Resources
Continue to
pursue watershed
county-wide
management
approach with
added emphasis
on land use
planning
Mecklenburg County SWIM staff
coordinates and improves
cooperation among Engineering,
MCDEP, Stormwater Services,
Parks and Recreation, CMUD and
Planning Commission to address
water quality issues; and explore the
revision of projected land uses with
the goal of incorporating “smart
growth” concepts and open space
preservation programs to protect
environmental resources.
Status: Ongoing
Specific “smart
growth” and open
space concepts are
prioritized in
discussions of
coordination and
cooperation efforts of
Part 7 of the SWIM
Phase 1 Strategy
during the first half of
2000.
Mecklenburg
County
NC
Division of
Water
Resources
Continue to
pursue watershed
county-wide
management
approach with
added emphasis
on stream
restoration
Mecklenburg County staff works with
North Carolina Wetlands Restoration
Program to identify restoration sites
in the County and use wetland
impact fees generated within
Mecklenburg County to restore
county streams
Status: Ongoing
Discussions with
Wetlands
Restoration Program
staff continue.
Potential restoration
sites are in the
process of being
identified and
progress should
occur during 2001.
Mecklenburg
County
NC
Division of
Water
Resources