2003 IBT Annual Report final

2003 ANNUAL REPORT on INTERBASIN TRANSFERS
For
RTP South and the Towns of Cary, Apex, and Morrisville

Prepared for:
Town of Apex
Town of Cary
Town of Morrisville
RTP South/Wake County

Submitted to:
North Carolina Division of Water Resources

April 2004

Prepared by:
Leila R. Goodwin, P.E.
Water Resources Manager
Town of Cary
P.O. Box 8005
Cary, NC 27512-8005
919-462-3846
[e-mail]

Table of Contents
Executive Summary............................................................................................................... ES-1
1. Jordan Lake Allocation Monitoring......................................................................... 1-1
2. IBT Monitoring............................................................................................................ 2-1
3. Compliance with Certificate Conditions................................................................ 3-3

Appendix A: Daily Tracking of Combined Jordan Lake Water Supply Allocations for
2003...................................................................................................................A-1
Appendix B: Daily Interbasin Transfer Estimates for 2003.............................................B-1

2003 ANNUAL REPORT ON INTERBASIN TRANSFERS for RTP South and the Towns of Cary, Apex, and Morrisville
ES-1
Executive Summary
The 2003 Annual Report on Interbasin Transfers for RTP South and the Towns of Cary,
Apex, and Morrisville includes monitoring data for daily tracking of IBT amounts and
combined Jordan Lake allocations held by the certificate holders. The 2003 Annual Report
also includes information pertaining to new conservation easements in Research Triangle
Park and new buffer rules in Wake County (pertaining to condition 8 of the IBT certificate).
In 2003, the certificate holders complied with all conditions of their IBT certificate. The
maximum daily IBT amount for Cary, Apex, Morrisville, and RTP South was 17.8 million
gallons per day (mgd). The annual average IBT amount was 13.4 mgd. IBT amounts and a
summary of Jordan Lake withdrawals are provided in Table ES-1. The daily IBT amounts in
2003 for Cary, Apex, Morrisville, and RTP South are shown in Figure ES-1.
TABLE ES-1.
Summary of InterBasin Transfers for Cary, Apex, Morrisville and RTP South

Withdrawal from Haw
Subbasin
(mgd)1
Total Return to Haw
Subbasin
(mgd)
Interbasin Transfer
(mgd)
IBT as % of
Certificate
Calendar
Year
Average
Annual
Max. Day Average
Annual
Max. Day Average
Annual
Max. Day Max.
1998 10.8 15.7 1.7 3.5 9.0 14.3 90%
1999 9.2 15.6 1.6 4.2 7.6 12.9 81%
2000 7.3 14.2 1.1 4.4 6.2 11.8 74%
20012 9.7 18.8 2.8 9.4 6.8 15.0 63%3
2002 16.9 29.2 3.5 10.3 13.5 22.5 94%
2003 15.9 22.7 2.5 5.5 13.4 17.8 89%
1. Includes water use by Cary, Apex, Morrisville, and RTP South.
2. Withdrawals in 2001 were unusually high due to construction activities at the Cary/Apex WTP and do not reflect actual
potable water demands.
3. Permitted IBT amount increased from 16 mgd to 24 mgd in July 2001. The maximum day IBT of 15.0 mgd occurred
after the permitted amount increased to 24 mgd.
2003 ANNUAL REPORT ON INTERBASIN TRANSFERS for RTP South and the Towns of Cary, Apex, and Morrisville
ES-2
Figure ES-1: Daily Interbasin Transfer for Cary, Apex, Morrisville and RTP South
[Haw Sub-Basin to Neuse Sub-Basin]
0.00
5.00
10.00
15.00
20.00
1/1/03 2/1/03 3/1/03 4/1/03 5/1/03 6/1/03 7/1/03 8/1/03 9/1/03 10/1/03 11/1/03 12/1/03
In
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Cary Apex Morrisville RTP
2003 ANNUAL REPORT ON INTERBASIN TRANSFERS for RTP South and the Towns of Cary, Apex, and Morrisville
1-1
1.0 Jordan Lake Allocation Monitoring
The combined Jordan Lake water supply allocation for Cary, Apex, Morrisville, and RTP
South can be tracked on a daily basis. Daily tracking of the combined Jordan Lake
allocation for the period January 1, 2003 through December 31, 2003 is included in Appendix
A. The water supply pools for each allocation holder were full on January 1, 2003.
For 2003, the maximum day withdrawal for all certificate holders was 22.7 mgd, which
occurred on May 14. The average daily withdrawal for all certificate holders was 15.9 mgd
during 2003 (Table 1-1).
TABLE 1-1
Summary of Jordan Lake Withdrawals1
Year Average Annual Withdrawal
(mgd)
Maximum Daily Withdrawal
(mgd)
19982 10.8 15.7
19992 9.2 15.6
2000 7.3 14.2
2001 9.7 18.8
2002 16.9 29.2
2003 15.9 22.7
1. Withdrawals from Jordan Lake at the Cary/Apex raw water intake. Includes water use by Apex, Cary, Morrisville and
RTP South. Does not include water use by Durham.
2. Includes water use by Holly Springs from 1/1/98 to 6/30/99
Table 1-2 presents historical water use for the certificate holders (Cary, Apex, Morrisville,
and RTP South) based on finished water produced at the Cary/Apex WTP. In 2003,
finished water demands averaged 14.0 mgd and the maximum day demand was 19.9 mgd.
The maximum day peaking factor was 1.43 in 2003.
TABLE 1-2
Summary of Finished Water Demands
Year
Average Annual
Demand
(mgd)
Maximum Daily Demand
(mgd)
Maximum Day/Average
Day Peaking Factor
19982 12.2 20.1 1.64
19992 12.6 21.5 1.70
2000 13.0 21.6 1.66
2001 14.1 22.0 1.56
2002 14.9 25.6 1.72
2003 14.0 19.9 1.43
1. Includes finished water delivered to the distribution system by the Cary/Apex WTP.
2. Includes water use by Holly Springs from 1/1/98 to 6/30/99.
2003 ANNUAL REPORT ON INTERBASIN TRANSFERS for RTP South and the Towns of Cary, Apex, and Morrisville
1-2
Water use for Morrisville and RTP South is not measured on a daily basis. Therefore,
accurate daily tracking of Jordan Lake water supply allocations can only be performed for
the combined Jordan Lake water supply allocation for Cary, Apex, Morrsiville, and RTP
South. Figure 1 shows the water supply withdrawals and the allocation storage level for
2003. The combined allocated storage stayed at 100 percent full for all of 2003.
Figure 1. Cary/Apex/Morrisville/RTP South Water Supply Allocation and
Withdrawals for 2003
6,700
8,700
10,700
12,700
14,700
16,700
1-Jan 31-Jan 2-Mar 2-Apr 2-May 2-Jun 2-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec 31-Dec
St
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a
g
e

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(
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10.00
12.00
14.00
16.00
18.00
20.00
22.00
24.00
Wa
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Full Pool
= 39% of Water Supply Pool
= 17,862 acre-feet
Individual Jordan Lake water allocations are estimated on a daily basis by estimating daily
water usage for Morrisville and RTP South from monthly records. Daily water use for
Morrisville is estimated from monthly or more frequent retail meter readings by assuming
that water usage variations between meter readings follow the same patterns as the total
combined water use (“Net Cary” use). Daily water use for RTP South is estimated similarly
using monthly retail meter readings. by assuming that water usage trends throughout the
month follow similar patterns as for Cary. For a given day, the ratio of daily Net Cary water
use to average net Cary water use for the period between meter readings is applied to
Morrisville and RTP South metered water use.
Levels in individual water supply pools are calculated on a daily basis using daily water use
estimates and daily lake inflows. Lake inflow data is obtained from the US Army Corps of
Engineers and allocated to each water supply pool according to the percentage allocation
held. Any inflow amount that would fill the allocated storage above 100 percent is not
stored. Any time the elevation in Jordan Lake is at or above 216 feet mean sea level, the
water supply pools are reset to 100 percent full. If any allocation holder or larger pool has
excess inflow, it is first distributed within that pool to another user, if needed, before being
“spilled”.

2003 ANNUAL REPORT ON INTERBASIN TRANSFERS for RTP South and the Towns of Cary, Apex, and Morrisville
1-3
The daily Cary/Apex withdrawal amounts are estimated by subtracting the estimated daily
Morrisville and RTP amounts from the metered total daily use; Cary amounts are then
estimated by subtracting the daily recorded Apex use from the remainder. Cary/Apex
holds a water supply storage allocation equal to 32 percent of the water supply pool or 9,618
acre-feet.
The allocated storage for each of the four users – Cary, Apex, Morrisville and RTP South –
remained at 100 percent full for all of 2003.
2003 ANNUAL REPORT ON INTERBASIN TRANSFERS for RTP South and the Towns of Cary, Apex, and Morrisville
2-3
2.0 IBT Monitoring
Daily IBT estimates for the certificate holders are included in Appendix B. Estimates are
provided for the period January 1, 2003 through December 31, 2003. The maximum day IBT
transfer during the calendar year 2003 was 17.8 mgd, which occurred on May 13, 2003. This
represents 74 percent of the permitted IBT transfer under the certificate approved by the
EMC on July 12, 2001. The annual average IBT transfer was 13.4 mgd during calendar year
2003.
The average daily consumptive use was 10% for the period January 1, 2003 through
December 31, 2003. Historical consumptive use is shown in Table 2-1.
The distribution of consumptive uses between the Haw, Cape Fear, and Neuse River
subbasins for 2003 was based on historical water use in each basin as determined by billing
records for each certificate holder. For 2003, it was assumed that 23% of water use occurred
in the Haw subbasin, 0.6% of water use occurred in the Cape Fear subbasin, and 76.4% of
water use occurred in the Neuse River subbasin. The certificate holders have begun
tracking historical use by assigning a subbasin to each customer. Data on the distribution of
water use between subbasins for each entity from 2000 through 2003, based on billing
records, is shown in Table 2-2.
In 1998, 1999, and 2000 Apex and Cary implemented mandatory irrigation restrictions due
to water supply limitations and IBT permit restrictions. The Town of Morrisville asked
residents to voluntarily conserve water beginning in 1998, and implemented mandatory
water use restrictions in July 1999. The restrictions reduced consumptive water use from
what would normally be expected during those years. In 2002 all the Towns had mandatory
restrictions because of regional drought conditions, but they were implemented after June,
which was when all-time high water use occurred. There were no water restrictions in 2003.
TABLE 2-1
Historical Consumptive Use for Cary, Apex, Morrisville, and RTP South
Year
Average Daily Finished
Water Demand
(mgd)
Average Daily
Consumptive Use
(mgd)
% Consumptive Use
19981 12.2 2.4 19.7%
19991 12.6 2.1 16.7%
2000 13.0 1.8 13.8%
2001 14.1 2.0 14.7%
2002 14.9 3.0 20.0%
2003 14.0 1.4 10.0%
1. Includes some water use by Holly Springs. Holly Springs purchased water from Apex in 1998 and 1999.
2003 ANNUAL REPORT ON INTERBASIN TRANSFERS for RTP South and the Towns of Cary, Apex, and Morrisville
2-3
TABLE 2-2
Distribution of Water Billed to Retail Customers by River Subbasin
Year Cary Apex Morrsiville1 RTP South

Total
Water
Use
(mgd)
Water
Use in
Haw
(mgd)
% Use
in Haw
Total
Water
Use
(mgd)
Water
Use in
Haw
(mgd)
% Use
in Haw
Water
Use in
Cape
Fear
(mgd)
% Use
in Cape
Fear1
Total
Water
Use
(mgd)
Water
Use in
Haw
(mgd)
% Use
in Haw2
Total
Water
Use
(mgd)
Water
Use in
Haw
(mgd)
% Use
in Haw
2000 9.29 0.82 8.8% 1.65 0.82 49.9% 0.07 4.3% 0.86 0.05 6.20% 0.27 0.27 100%
2001 10.73 1.07 10.0% 1.88 1.03 54.8% 0.08 4.3% 1.05 0.06 6.20% 0.31 0.31 100%
2002 10.23 1.23 12.0% 2.15 1.29 60.0% 0.08 3.7% 1.18 0.14 11.2% 0.39 0.39 100%
2003 9.02 0.75 8.3% 1.94 1.15 59.3% 0.073 3.8% 1.10 0.15 14.0% 0.36 0.36 100%
1. Water use by basin for the Town of Morrisville is unavailable for 2000, and so was assumed to be the same as in 2001.
2003 ANNUAL REPORT ON INTERBASIN TRANSFERS for RTP South and the Towns of Cary, Apex, and Morrisville
2-3
Table 2-3 shows the combined water use for each of the certificate holders and the
percentage water use in the Haw and Cape Fear River Subbasins.
TABLE 2-3
Historical Water Use in the Haw and Cape Fear River Subbasins for Cary, Apex, Morrisville, and RTP South
Year Total Billed
Water Use
(mgd)
Water Use in
Haw Subbasin
(mgd)1
Percent Use in
Haw Subbasin
Water Use in
Cape Fear
Subbasin
(mgd)1
Percent Use in
Cape Fear
River Subbasin
2000 12.07 1.97 16.3% 0.07 0.6%
2001 13.97 2.47 17.7% 0.08 0.6%
2002 13.95 3.05 21.8% 0.08 0.6%
2003 12.42 2.41 19.4% 0.07 0.6%
1. Water use by subbasin for the Town of Morrisville is unavailable for 2000, and so was assumed to be the same as in 2001.

For purposes of calculating daily IBT amounts in 2003, the certificate holders used 23% for
the portion of their water use that occurred in the Haw subbasin and 0.6% as the portion
used in the Cape Fear subbasin. For purposes of calculating daily IBT amounts in 2004, the
certificate holders estimate that 21% of their water use will occur in the Haw subbasin and
that 0.6% of their water use will occur in the Cape Fear subbasin.

2-3
3.0 Compliance with Certificate Conditions
A summary of the conditions of the IBT certificate dated July 12, 2001 along with the current status of compliance for each is
provided below.
Condition 1 (2010 Required Return)
The holders of the certificate, after 2010, shall return water supplied from the Haw River Basin used in the Neuse River Basin to either the Haw or
Cape Fear River Basins as described below.
a) Any water use in the Neuse Basin in excess of 16 million gallons per day adjusted on an average daily basis shall be returned.
b) Water used for consumptive purposes in the Neuse Basin will not be subject to this condition
Compliance with this condition is not required until after 2010. However, the calculations for determining compliance with
Condition 1 are shown in Table 3-1. Note that revised calculations for 2001 result in different values then were included in the 2001
Annual Report.
Wake County, Cary, Apex and Morrisville are participating in the Western Wake County Regional Wastewater Treatment Study
along with Holly Springs and Fuquay-Varina. The partners expect to select an alternative for implementation in the summer of 2004.
More information about the status of the study can be found on Cary’s website at
http://www.townofcary.org/depts/pwdept/capefear/index.htm.
TABLE 3-1
Summary of Compliance with Certificate Condition No. 1
Year
Neuse
Finished
Water from
the Haw
(mgd)
Peaking
Factor
16 mgd
MDD
adjusted to
ADD
Consumptive
Use Factor
(%)
Neuse
Consumptive
Use (from the
Haw)
(mgd)
Required
Return if
After 2010
(mgd)
Amount
Returned
(mgd)
(a) (b) (c)=16/(b) (d) (e)=(a)*(d) (f)=(a)-(c)-
(e)
(g)
2001 6.8 1.64 9.8 20% 1.4 0.0 0
2002 13.5 1.64 9.8 20% 2.7 1.0 0
2003 13.4 1.64 9.8 20% 2.7 1.0 0
2003 ANNUAL REPORT ON INTERBASIN TRANSFERS for RTP South and the Towns of Cary, Apex, and Morrisville
3--4
TABLE 3-1
Summary of Compliance with Certificate Condition No. 1
Year
Neuse
Finished
Water from
the Haw
(mgd)
Peaking
Factor
16 mgd
MDD
adjusted to
ADD
Consumptive
Use Factor
(%)
Neuse
Consumptive
Use (from the
Haw)
(mgd)
Required
Return if
After 2010
(mgd)
Amount
Returned
(mgd)
a = Average annual transfer from Haw to Neuse (see Table B-1)
b = Peaking factor specified in Certificate for first year, and to be approved by DWR thereafter
d = Percent consumptive use specified in Certificate for first year and to be approved by DWR thereafter
g = Average annual wastewater discharges and water reuse in Haw and Cape Fear Basins (see Table B-1)

Condition 2 (Facilitate Allocation Use)
The holders of this certificate shall manage the authorized transfer amount in such a way that none of
the individual petitioners (Towns of Cary, Apex, Morrisville, and Wake County [for RTP South]) are
prevented from fully using their respective Jordan Lake water supply allocations.
The IBT was not a limitation on Jordan Lake withdrawals for any of the allocation holders in
2003.
Condition 3 (Disagreggation of IBT Amount)
If the certificate holders discontinue their cooperative service agreement with each other, the
maximum day permitted transfer will be adjusted by the Division of Water Resources based on the
2030 projected of each applicant at that time.
The cooperative service agreements between the certificate holders have remained in effect
during 2003.
Condition 4 (Compliance and Monitoring Plan)
Prior to transferring water under this certificate, the holders of this certificate shall work with the
Division of Water Resources to develop compliance and monitoring plan subject to approval by the
Division. The plan shall include methodologies and reporting schedules for reporting the following
information: maximum day transfer amounts, compliance with permit conditions, progress on
mitigation measures, drought management, and reporting. A copy of the approved plan will be kept
on file with the Division for public inspection. The Division of Water Resources shall have the
authority to make modifications to the compliance and monitoring plan as necessary to assess
compliance with the certificate.
Cary, Apex, Morrisville, and RTP South submitted a Compliance and Monitoring Plan
concurrent with the submittal of the 2001 report. In 2003 the Division of Water Resources
agreed to modify the submittal date of each annual report to be May 1 of the following year.
Condition 5 (EMC Consideration of Impacts)
If either the EIS is found at a later date to be incorrect or new information becomes available such that
the environmental impacts associated with this transfer are substantially different from those
projected impacts that formed the basis for the above Findings of Fact and this certificate, the
Commission may reopen the certificate to adjust the existing conditions or require new conditions to
ensure that the detriments continue to be mitigated to a reasonable degree.
2003 ANNUAL REPORT ON INTERBASIN TRANSFERS for RTP South and the Towns of Cary, Apex, and Morrisville
3--5
This condition requires no action by the certificate holders.
Condition 6 (Intake Access)
The Towns of Cary and Apex shall be required to provide access at their existing intake site to other
Jordan Lake water allocation holders that need access to utilize their allocation to the extent that this
additional use is determined to be feasible by the Division of Water Resources. The cost associated
with getting the necessary permits, engineering design, and associated construction costs are the
responsibility of the allocation holder(s) requesting the access and not Cary and Apex.
The Town of Cary has continued to provide retail water service to RTP South and has a bulk
purchase agreement with the Town of Morrisville. The Towns of Cary and Apex have also
entered into an agreement to allow Chatham County access to the Cary/Apex raw water
intake on Jordan Lake.
Condition 7 (Drought Management Plan)
Prior to transferring water under this certificate, the Towns of Cary, Apex, and Morrisville, and
Wake County (for RTP South) shall develop individual water shortage response plans subject to
approval by the Division. The holders of this certificate shall develop a drought management plan for
the interbasin transfer, incorporating the individual water shortage response plans and subject to
approval by the Division. The plans shall tie specific water conservation actions to the percent
storage remaining in each of the petitioners’ Jordan Lake water supply accounts. A copy of the
approved plans shall be kept on file with the Division for public inspection. The Division of Water
Resources shall have the authority to approve modifications to the drought management plan as
necessary.
Water Shortage Response Plans for each certificate holder were submitted as attachments to
the 2001 Annual Report.
Condition 8 (Stream Buffer Rules)
Within six months from the effective date of this certificate, the Towns of Cary, Apex, and
Morrisville, and Wake County (for RTP South) shall enact ordinances similar to or more protective
than the Neuse River buffer rules (15A NCAC 2B.0233) for the parts of their jurisdictions that are
within the Jordan Lake watershed. These buffer requirements shall be subject to approval by the
Division of Water Resources after consultation with the Division of Water Quality and shall be
adopted as local ordinances.
Each Town’s buffer ordinance was submitted with the 2001 Annual Report. In 2003 there
were two changes:
1. The Research Triangle Foundation put 15,240 feet of 50-foot wide stream buffers
under a conservation easement.
2. Wake County prohibited development in the floodplain, and expanded the buffers
required in water supply watersheds from 50 feet on each side to 100 feet on each
side of the stream.

A-1

Appendix A:
Daily Tracking of Combined Jordan Lake Water Supply
Allocations for 2003
2003 ANNUAL REPORT ON INTERBASIN TRANSFERS for RTP South and the Towns of Cary, Apex, and Morrisville
B-1

Appendix B
Daily Interbasin Transfer Estimates for 2003