2009 IBT Annual Report

  
Page 2 of 6

Charlotte-Mecklenburg Utilities
Annual Report on Interbasin Transfer
Calendar Year 2009

The North Carolina Environmental Management Commission (EMC) approved Charlotte
Mecklenburg Utilities’ (Utilities’) petition to increase the amount of water transferred from the
Catawba basin to the Rocky River basin and an interbasin transfer (IBT) Certificate was issued
on March 14, 2002. The Certificate authorizes Utilities to transfer up to 33 million gallons per
day (mgd) from the Catawba River basin to the Rocky River basin.

The IBT Certificate requires Utilities to report maximum daily IBT amounts annually to the
North Carolina Division of Water Resources (NC DWR) until such time as the transfer amount
exceeds 80% of the authorized amount. Once that amount is exceeded, Utilities is required to
report monthly. To date, Charlotte-Mecklenburg Utilities has not exceeded 80% of the
authorized IBT amount.

System Overview
The Utilities operates the water and wastewater systems that serve Charlotte, Cornelius,
Davidson, Huntersville, Mint Hill, Matthews, Pineville, and much of the unincorporated areas of
Mecklenburg County. This system is divided between two river basins designated by NC
General Statutes for regulation of IBT water. The western portion of the system is within the
Catawba River basin and the eastern portion is within the Rocky River basin. Water transferred
from the Catawba River basin to the Rocky River basin that is not returned to the Catawba is
regulated IBT.

Water for distribution to Utilities’ customers is withdrawn from the Catawba River basin at two
locations. An intake at Lake Norman sends water to the Lee S. Dukes Water Treatment Plant. A
second intake at Mountain Island Lake sends water to the Walter M. Franklin Water Treatment
Plant and to the Vest Water Treatment Plant. Potable water from these three plants is delivered
through an interconnected distribution system to retail customers throughout Utilities’ service
area in Mecklenburg County and in small areas of Iredell, Cabarrus, and Union Counties. The
Utilities also provides wholesale water to municipal systems for Resale including: City of
Concord (NC), Town of Harrisburg (NC), Union County (NC), York County Water & Sewer
Authority (SC), and Lancaster County Water and Sewer District (SC).

Utilities treats wastewater at five advanced wastewater treatment plants (WWTP’s) which
discharge into small streams in Mecklenburg County. Four of the streams are tributary to the
Catawba River basin and one (Mallard Creek) is tributary to the Rocky River basin. Utilities also
conveys wastewater generated in portions of Mecklenburg County to the Rocky River Regional
Wastewater Treatment Plant (RRRWWTP) operated by the Water and Sewer Authority of
Cabarrus County (WSACC). The RRRWWTP discharges treated effluent to the Rocky River.

Page 3 of 6

IBT Monitoring
Water supplied to Utilities’ retail customers in the Rocky River Basin, that is not returned to the
Catawba basin, is included in the reported IBT amounts. Water provided to municipalities with
service areas in the Rocky River basin include the City of Concord and the Town of Harrisburg.

Utilities can transfer treated potable water to the City of Concord through three metered
connections to their water system. All of Concord’s service area is within the Rocky River
basin, so any water purchased by them becomes an IBT. Water service is only provided as an
emergency back-up to Concord’s routine supply which is Lake Howell and several smaller
reservoirs. All of these reservoirs are within the Rocky River basin. Wastewater from Concord
is treated at the RRRWWTP. Utilities’ agreement with Concord is that water will be supplied to
them subject to availability and subject to regulatory constraints including IBT and Federal
Energy Regulatory Commission (FERC) limitations.

Concord received an IBT Certificate in January 2007, for the transfer of up to 10 mgd from the
Catawba River basin to the Rocky River basin. NC DWR advised Utilities that water sold to
Concord should not be applied to Utilities’ IBT amount. Concord did not purchase any potable
water from Utilities in calendar year 2009, so the IBT amounts reported do not include sales to
Concord.

Utilities can transfer treated potable water to the Town of Harrisburg through two metered
connections to their water system. All of Harrisburg’s service area is within the Rocky River
basin and is included in the Utilities’ IBT amounts.

Table 1 below summarizes actual IBT amounts for calendar years 2002 through 2009 (all
calculated using the methodology approved by NC DWR in June of 2006). The table considers
the daily amounts of water transferred from the Catawba basin to customers within the Rocky
River basin that is not returned to the Catawba basin.

The data indicates that the maximum amount of IBT for year 2009 occurred in August, and was
16.00 mgd, less than 49% of the authorized maximum day value of 33 mgd. The average IBT for
2009 was 12.04 mgd, which is approximately 36% of the authorized maximum day value. In
addition to the amount of actual IBT reported in Table 1, Utilities has committed to provide
additional IBT to development that has been proposed but not yet activated in the Rocky River
basin. As of December 31, 2009, 1.41 mgd was committed to permitted donated projects
(subdivisions) that had not been activated and 0.22 mgd was committed to master meter
connections (generally commercial or multi-family developments) that had not been activated,
both based on maximum day estimates. This brings the total of the actual and outstanding IBT in
2009 to 17.63 mgd, or less than 54% of the authorized maximum day value.

Page 4 of 6

Table 1. Actual IBT Summary
Calendar Year Avg. Annual IBT (mgd) Max. Day IBT (mgd)
2002 6.74 11.97
2003 6.91 9.82
2004 7.79 12.56
2005 8.66 13.79
2006 9.56 14.35
2007 9.96 17.22
2008 11.39 17.42
2009 12.04 16.00

Compliance with Certificate Conditions
Condition 1 of Utilities’ IBT certificate requires Mecklenburg County to summarize progress in
implementation of watershed management approaches of the Surface Water Improvement and
Management Program (S.W.I.M. program). This summary follows:

The watershed management approaches of the Surface Water Improvement and Management
(SWIM) Program continued to be implemented during calendar year 2009. Efforts continued
to focus on McDowell and Goose Creeks as in 2007 and 2008 but were expanded to include
the South Prong and West Branch of the Rocky River in Davidson during 2009. During
calendar year 2009, the following work was completed in the three (3) watersheds:
a) Construction was completed for
the installation of three (3) large
rain gardens at the North
Mecklenburg Recycling Center
located in the Torrence Creek
Watershed, which is a tributary of
McDowell Creek in Huntersville.
These rain gardens collect and
treat 100% of the storm water
runoff from the facility resulting
in a reduction in the pollutant
load entering Torrence Creek.
The total cost for the project was
$307,000. Forebay and Rain Garden (grassed) at Recycling Center
b) Planning and design was completed for a stream restoration project including 7,700 feet
in the main stem of Torrence Creek starting at McCoy Road and 9,000 linear feet

Page 5 of 6

of Torrence Creek Tributary #2 from I-77 to Bradford Hill Lane. Construction is to be
completed by December 2010. The total cost for the project is estimated at $2,000,000.

c) Planning and design is underway for the restoration of Upper McDowell Creek in
Cornellius, NC. The project will restore some of the most severely damaged sections of
McDowell Creek and install BMPs to treat urban runoff before it enters the creek. The
project is being funded by Cornelius, Mecklenburg County and the North Carolina 319
Grant Program. The total cost for the project is not available.

d) Mecklenburg County continues to partner with Creek ReLeaf, the Sierra Club and local
schools to plant trees along the banks of McDowell Creek to restore the water quality
buffer and floodplain. During 2009, over 2,500 trees were planted by approximately 400
volunteers along the floodplain in McDowell Creek.

e) The Goose Creek Watershed Management Plan was finalized and implementation
initiated. One of the primary implementation measures was the inspection of all of the
septic systems in the watershed to ensure that they are functioning properly and that all
problems are corrected to prevent the discharge of sewage. Plans are to inspect all the
septic systems in the watershed by June, 2011.

f) Efforts began toward the drafting of the Rocky River Watershed Management Plan.
Field work commenced during the second half of 2009. 

Condition 2 of Utilities’ IBT certificate required a stakeholder process to investigate, develop,
adopt, and implement storm water ordinances that control water quantity from single-family
development and water quality for all development until completed. The requirements of
Condition 2 were completed in 2007.

Condition 3 of the IBT Certificate removes the Goose Creek subbasin from the area to be served
by the IBT, and imposes a moratorium on the installation of new IBT water lines (water lines
crossing the ridgeline) into Goose Creek subbasin until the impacts of additional growth on the
endangered species are fully evaluated.
The Utilities has requested the NC Division of Water Resources (DWR) to prepare an
Environmental Assessment (EA) of new development in the Goose Creek basin (Mint Hill
area), impacts to water quality, and measures required to protect the Carolina
Heelsplitter.

Page 6 of 6

Condition 4 of the IBT Certificate provides that the Environmental Management Commission
may reopen the Certificate under certain circumstances. This did not occur in 2009.

Condition 5 of the IBT Certificate requires Utilities to develop a compliance and monitoring plan
for reporting maximum daily transfer amounts, compliance with certificate conditions, and
progress on mitigation measures, and drought management activities. Utilities’ monitoring plan
and reporting format were approved in June of 2006 by NC DWR and continue to be used for
2009.

2009 showed slow, but steady improvement from the drought conditions that gripped our
state. The Catawba-Wateree Basin was slow to recover normal stream flows and the ground
water lagged well behind surface water recharge. Charlotte Mecklenburg Utilities along
with the other utilities in the Catawba-Wateree Basin remained in level 2 water restrictions
until May 2009, in accordance with the Low Inflow Protocol adopted by the region’s drought
management group.
Customer consumption did not return to pre drought levels after the easing of restrictions in
2008 and did not rebound upward after the lifting of all restrictions in 2009. In fact, water
use continued to decline in the Charlotte region. Even without restrictions, per account
usage hit an all time low in 2009 for Charlotte Mecklenburg Utilities customers.
Water use in the Catawba – Wateree River Basin continued to track below historic average
levels and closed out the year approximately 12 - 15% below normal.

Summary
The actual maximum day amount of water transferred from the Catawba River basin to the
Rocky River basin was 16.00 mgd, less than 49% of the authorized maximum day value of 33
mgd. The total of actual and outstanding IBT was 17.63 mgd, less than 54% of the authorized
maximum day value. Utilities is in full compliance with IBT authorizations and compliance
conditions for calendar year 2009.