Yadkin River Basin Modeling Report 2025

Yadkin-Pee Dee River Basin
Hydrologic Modeling Report
A Supplemental Document

2025

N.C. Division of Water Resources

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Table of Contents
Executive Summary ....................................................................................................................... 1
1. Introduction ......................................................................................................................... 1
1.1. River Basin Description .......................................................................................................... 1
1.2. Basin Water Resources Plan ................................................................................................... 1
2. Basin Hydrologic Model (OASIS Model).................................................................................... 2
2.1. Scope of the Model ............................................................................................................... 2
2.2. Model Schematic .................................................................................................................. 3
2.3. Input Data ............................................................................................................................ 6
2.3.1. Hydrology ............................................................................................................................ 6
2.3.2. Water Use and Demand ......................................................................................................... 9
2.3.3. Reservoirs and Operation Information ................................................................................... 10
2.4. Model Output Options ........................................................................................................ 18
3. Modeling Results: Basinwide Impact ..................................................................................... 19
3.1. Demand Scenarios Modeled ................................................................................................ 19
3.2. Water Use and Wastewater Discharge ................................................................................... 19
3.3. Outputs – Changes in Water Availability and Reliability ........................................................... 26
3.3.1. Impacts on PWSSs ............................................................................................................... 27
3.3.2. Impacts on Reservoirs ......................................................................................................... 34
3.3.3. Overall Performance Measures ............................................................................................. 42
3.3.4. Future Works: ..................................................................................................................... 50

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Figures
Figure 1: Yadkin-Pee Dee River Basin Interbasin Transfer Basins and HUC-8 Subbasins .............................. 3
Figure 2: Yadkin-Pee Dee and Lumber River Basin OASIS Model Schematic – Close View ........................... 4
Figure 3: Yadkin-Pee Dee and Lumber River Basin OASIS Model Schematic – Full Basin View .................... 5
Figure 4: Map of gages used as inflow nodes in the Yadkin-Pee Dee and Lumber River Basins ................... 9
Figure 5: Diagram of Reservoir Operational Zones and Rule Curves. ......................................................... 17
Figure 6: Comparison of Simulated Annual Average Water Use by Types for Simbase Scenario ............... 20
Figure 7: Comparison of Simulated Annual Average Water Use by Watershed for the Simbase Scenario 20
Figure 8: Purchase – Sale Connections Example ......................................................................................... 23
Figure 9: Upper Pee Dee Percent Area Drought Monitor Categories in 2002 ............................................ 31
Figure 10: Upper Pee Dee Percent Area Drought Monitor Categories in 2007-2008 ................................. 31
Figure 11: North Carolina Drought Monitor Map on December 25, 2007 ................................................. 31
Figure 12: Asheboro System Lake Storage Percentage During 2002 Drought – Demand 2070 .................. 35
Figure 13: Asheboro Lake Lucas Elevation Durations for Simbase, 2040 and 2070 .................................... 36
Figure 14: Lake Howell Elevation Comparison During 2002 Drought – Simbase, 2040 and 2070 .............. 37
Figure 15: Lake Howell Storage with Drought Plan On/OFF for Simbase During 2002 Drought ................. 38
Figure 16: Lake Concord Elevation Comparison During 2002 Drought ....................................................... 39
Figure 17: Storage Percent Comparison for Black Run Creek Reservoir – 1994 and 2002 Drought ........... 40
Figure 18: Useable Storage Percent for Monroe Lakes ............................................................................... 41

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Tables
Table 1: Yadkin-Pee Dee River Basin Interbasin Transfer Basins and HUC 8 Subbasins ................................ 3
Table 2: Yadkin-Pee Dee River Basin OASIS Model Nodes ............................................................................ 6
Table 3: List of Gages used in the Yadkin-Pee Dee River Basin Model Inflow Development ........................ 7
Table 4: Yadkin-Pee Dee River Basin Reservoir Information used in the Model ......................................... 11
Table 5: W. Kerr Scott Reservoir Minimum Releases .................................................................................. 12
Table 6: Normal Minimum Elevations for Hydropower Reservoirs in LIP, (Feet USGS datum - NGVD 1929)
.................................................................................................................................................................... 13
Table 7: Summary of LIP Triggers ................................................................................................................ 14
Table 8: Prescribed LIP Flows (1), Cubic Feet per Second (CFS) .................................................................. 14
Table 9: Tributary Lakes Minimum Release for Drought Triggers ............................................................... 15
Table 10: WSRP Induced Triggers ................................................................................................................ 16
Table 11: Fish Spawning Season Requirements as Modeled ...................................................................... 17
Table 12: Simulated Annual Average Adjusted Demand, Delivery and Wastewater Return Flows (WW RF)
for Simbase Scenario ................................................................................................................................... 21
Table 13: Annual Average PWSS Demand Node Inputs for Simbase, 2040 and 2070 Scenarios ................ 22
Table 14: Purchase – Sale Contract Amounts in Model, MGD .................................................................... 24
Table 15: Yadkin Pee Dee River Basin Interbasin Transfer Certificates ....................................................... 25
Table 16: Union County IBT Future Sources as Modeled ............................................................................ 26
Table 17: Shortage Summary for PWSSs Nodes without a WSRP or LIP with Drought Plans ON/OFF ....... 28
Table 18: Shortage Summary for WSRP and/or LIP Nodes with Drought ON ............................................ 29
Table 19: Shortage Summary for WSRP/LIP Nodes with Drought OFF ....................................................... 30
Table 20: Summary of Drought Stages for the Yadkin-Pee Dee PWSSs with WSRP and/or LIP .................. 33
Table 21: Simulated Lowest Value of Required Minimum Releases Estimates Through Dams for Tributary
Water Supply Reservoirs ............................................................................................................................. 42
Table 22: Performance Measure for USACE Reservoir ................................................................................ 43
Table 23: Performance Measure for Cube Hydro – High Rock Lake ............................................................ 44
Table 24: Performance Measure for Cube Hydro – Tuckertown & Narrows (Badin Lake) .......................... 45
Table 25: Performance Measure for Cube Hydro – Falls Reservoir ............................................................. 46
Table 26: Performance Measure for Duke Energy – Lake Tillery ................................................................. 47
Table 27: Performance Measure for Duke Energy – Blewett Falls Reservoir .............................................. 48
Table 28: Performance Measure for LIP - Drought Management ............................................................... 49

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1

Executive Summary
North Carolina’s Basinwide Water Resources Management Plans (referred to as “basin plans”) are a
nonregulatory, watershed-based approach to restoring and protecting North Carolina’s water resources.
Basin plans provide information on water quality and water quantity related issues, activities, and data
analyses. The 2022 Yadkin-Pee Dee River Basin Plan was the fourth document developed for the Yadkin-
Pee Dee River basin.
The 2022 Yadkin-Pee Dee River Basin Plan included several general basinwide chapters. Chapter 1
introduced the plan and the basin planning process while chapters 2 through 6 addressed water quality
and water quantity issues basinwide. Chapter 5 focused on permitted and registered activities, primarily
related to water quality permitting, but also covered water supply programs. Chapter 6 focused entirely
on water quantity issues, including a water supply analysis using 2018 Local Water Supply Plan data and a
description of the 2020 combined hydrology model developed for the Yadkin-Pee Dee and Lumber River
basins as well as other water quantity topics. Chapters 7 through 12 examined the six primary subbasins
within the Yadkin-Pee Dee basin in North Carolina while Chapter 13 concentrated specifically on the High
Rock Lake Watershed in the upper half of the basin.
This report is a supplemental document to provide additional information on water quantity and
hydrologic model data analyzed after the 2022 Yadkin-Pee Dee River Basin Plan was developed. This
report includes water demand analyses based on data reported for 2021. This is the first ever document
prepared to include hydrologic modeling results for the Yadkin-Pee Dee River basin.
1. Introduction
1.1. River Basin Description
The Yadkin-Pee Dee River basin is the second largest basin in North Carolina, encompassing 7,221 square
miles and all or a portion of 24 counties. The entire basin spans three states and drains 18,864 square
miles of land that originates from a dense network of headwater streams in the Blue Ridge Mountains of
southern Virginia and northwestern North Carolina and drains to the Atlantic Ocean in South Carolina.
1.2. Basin Water Resources Plan
Chapter 6 of the 2022 Yadkin-Pee Dee River Basin Plan provides detailed water supply conditions at the
basin and subbasin levels. For long-term planning, the State uses computer models for evaluating
potential impacts of increased water withdrawals, and existing or new operational and regulatory
constraints during a low flow condition. The modeling tool was under development at the time of the
2022 Yadkin-Pee Dee River Basin Plan development. Hence, it was not possible to incorporate water
supply data from the plan into the model for any data analysis regarding projected water demand for
future growth that shows the impacts of the growing demands at the basin level. This supplemental
report identifies where existing surface water supplies may be sufficient or insufficient to meet water
demands for public water systems, and potential basin level impacts on reservoirs or rivers during low
flow conditions.

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2. Basin Hydrologic Model (OASIS Model)
In 2020, the North Carolina Division of Water Resources (DWR) started the combined hydrologic model
development project for the Yadkin-Pee Dee and Lumber River basins. The model was developed by
Hazen and Sawyer using Operational Analysis and Simulation of Integrated Systems, or OASIS, with
Operations Control Language, or OCL™, a generalized computer simulation program designed to
characterize water resource systems. More information on the hydrologic model and its capabilities are
described in the “Basin Hydrologic Model” section of chapter 6 and its appendix in the 2022 Yadkin-Pee
Dee River Basin Plan, as well as the “Modeling Yadkin-Pee Dee and Lumber River Basins Operations with
Oasis” report.
2.1. Scope of the Model
The geographic scope of the model extends from the headwaters of the Yadkin River in the Blue Ridge
Mountains in northwestern North Carolina to gages just below the North Carolina and South Carolina
state line for both Yadkin-Pee Dee and Lumber River basins. North Carolina defines 17 major river basins,
including the Yadkin-Pee Dee and Lumber as per NCGS §143-215.B. For this 2022 Yadkin-Pee Dee River
Basin Plan analysis, only the Yadkin-Pee Dee portion of the model is considered. The 2022 Yadkin-Pee
Dee River Basin Plan primarily focused on subbasin boundaries defined by the US Geologic Survey
(USGS) Hydrologic Unit Codes (HUCs). There are seven subbasins (HUC8) in the Yadkin-Pee Dee River
basin, including Lynches, which has minimal coverage in North Carolina and was not focused on in the
2022 Yadkin-Pee Dee River Basin Plan, but included in this model. It should also be noted that the 2022
Yadkin-Pee Dee River Basin Plan refers to HUC8 “subbasins” as HUC8 “watersheds”. Additionally, the
Department of Environmental Quality (DEQ) DWR water supply planning is based on four Interbasin
Transfer (IBT) basins defined as per NCGS §143-215.22G. Figure 1 and Table 1 show the coverage and the
differences between the two sets of planning boundaries.

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Figure 1: Yadkin-Pee Dee River Basin Interbasin Transfer Basins and HUC-8 Subbasins1

Table 1: Yadkin-Pee Dee River Basin Interbasin Transfer Basins and HUC 8 Subbasins
IBT Basins HUC 8 Subbasins*
18-1 Yadkin River HUC 03040101 Yadkin River Headwater
18-1 Yadkin River HUC 03040104 Lake Tillery/Pee Dee River
18-1 Yadkin River HUC 03040201 Pee Dee River
18-2 South Yadkin River HUC 03040102 South Yadkin River
18-3/18-1 Uwharrie River/Yadkin River HUC 03040103 Yadkin River
18-4 Rocky River HUC 03040105 Rocky River
18-4 Rocky River HUC 03040202 Lynches River
*Note the naming convention in this table follows the 2022 Yadkin-Pee Dee River Basin Plan, USGS Subbasin names are HUC
03040101 – Upper Yadkin, HUC 03040103 – Lower Yadkin, HUC 03040104 – Upper Pee Dee, HUC 03040201 – Lower Pee Dee.
2.2. Model Schematic
The OASIS model uses a map-based schematic that includes nodes for surface water withdrawals
(agricultural, municipal, and industrial), discharges (municipal and industrial), reservoirs, gage locations,
flow requirements associated with dams or run-of-the-river intakes, and points along the rivers where
flows are of interest. As shown in Figure 2 and Figure 3, the red triangles represent reservoirs or lakes,
the blue squares are the water withdrawal or demand nodes, the yellow ovals are the junction nodes,
the green ovals are the gages, the light blue ovals are the total withdrawal nodes, and the brown ovals

1 https://edocs.deq.nc.gov/WaterResources/DocView.aspx?id=2650412&dbid=0&repo=WaterResources&cr=1

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are the wastewater discharge nodes. The color-coded arcs connect the nodes to represent the different
types of flows from the nodes along the river reaches.
Even though for water management purposes the basin is divided into four IBT basins, for modeling
purposes the basin is segmented into smaller watersheds at the reservoir levels for water flow direction,
catchment and accounting purposes as shown in different colors in the schematic. The watersheds are
W. Kerr Scott Reservoir, High Rock Lake, Tuckertown Reservoir, Badin Lake (Narrows Reservoir), Falls
Reservoir, Lake Tillery, Blewett Falls Lake, Downstream (D/S) of Blewett Falls and Pee Dee (into South
Carolina) in the Yadkin-Pee Dee basin. These reservoir level watersheds are considered here to be
consistent with Yadkin-Pee Dee Water Management Group’s (YPDWMG) Water Resources Plan. A list of
different types of nodes and arcs to interconnect the nodes and water users in both Yadkin-Pee Dee
River basin is presented in Table 2.
Figure 2: Yadkin-Pee Dee and Lumber River Basin OASIS Model Schematic – Close View

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Figure 3: Yadkin-Pee Dee and Lumber River Basin OASIS Model Schematic – Full Basin View

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Table 2: Yadkin-Pee Dee River Basin OASIS Model Nodes
Types of Nodes*
Yadkin-Pee Dee River
Basin
Watersheds** 9
Gage Nodes 27
Reservoir Nodes*** 29
Demand Nodes 49
Municipal 31
Industrial 10
Agricultural 8
Total Withdrawal Node (Multi Supplier) 21
Intake Arcs 67
WTP Discharge Node 14
WWTP Discharge Node 47
Junction Node 129
Travel Time Reservoir Node 2
Regular Interconnection 13
Emergency Interconnection 27
Terminal Node 1
* There are other nodes outside of the Yadkin-Pee Dee River basin
** Including below NC Stateline
*** One reservoir without any physical data is added as lag node in the model
2.3. Input Data
The methodology for developing model data requires a large volume of varieties of input data. There are
three forms of input data.
• Hydrology – Streamflows & net evaporation (rainfall – evaporation) data in timeseries
• Water Use – Current use & projected future demands in static and pattern data format
• Reservoir Information – Reservoir physical data & operation rules in user-defined codes
2.3.1. Hydrology
The daily hydrology data is derived from the streamflow and rainfall data collected by the USGS gages or
stations, and evaporation data calculated for the reservoir open surface area. The current water use
condition simulations and evaluations of future water demands were analyzed in relation to the
hydrologic conditions that occurred in the basin for water year from October 1929 to September 2019,
including high flow events and several drought periods. Table 3 provides a list of all the USGS gages used
to develop the model hydrology or “inflow” data for the combined models; however, only 27 USGS gages

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are included in the model to be used as inflow nodes for Yadkin-Pee Dee basin. Other gages are used to
generate inflow data set for gages with missing data or partial records.
Table 3: List of Gages used in the Yadkin-Pee Dee River Basin Model Inflow Development2
Site
Number Site Name #
Years
Drainage
Area
(sq. mi.)
OASIS Model
Watersheds*
Yadkin-Pee Dee River Basin Gages
02111000 YADKIN RIVER AT PATTERSON, NC 79 28.8 W. Kerr Scott
02111180 ELK CREEK AT ELKVILLE, NC 53 50.9 W. Kerr Scott
02111500 REDDIES RIVER AT NORTH WILKESBORO, NC 79 89.2 High Rock
02112000 YADKIN RIVER AT WILKESBORO, NC 89 504 High Rock
02112120 ROARING RIVER NEAR ROARING RIVER, NC 51 128 High Rock
02112360 YADKIN RIVER AT ELKIN, NC 55 866 High Rock
02112250 MITCHELL RIVER NEAR STATE ROAD, NC 50 78.8 High Rock
02113000 FISHER RIVER NEAR COPELAND, NC 79 128 High Rock
02113850 ARARAT RIVER AT ARARAT, NC 55 231 High Rock
02114450 LITTLE YADKIN RIVER AT DALTON, NC 58 42.8 High Rock
02115360 YADKIN RIVER AT ENON, NC 55 1694 High Rock
02115500 FORBUSH CREEK NEAR YADKINVILLE, NC 32 22.1 High Rock
02115860 MUDDY CREEK NEAR MUDDY CREEK, NC 22 186 High Rock
02115900 SOUTH FORK MUDDY CREEK NR CLEMMONS, NC 19 42.9 High Rock
02116500 YADKIN RIVER AT YADKIN COLLEGE, NC 89 2280 High Rock
02117030 HUMPY CREEK NEAR FORK, NC 15 1.05 High Rock
02117500 ROCKY CREEK AT TURNERSBURG, NC 32 101 High Rock
02118000 SOUTH YADKIN RIVER NEAR MOCKSVILLE, NC 80 306 High Rock
02118500 HUNTING CREEK NEAR HARMONY, NC 68 155 High Rock
02119000 SOUTH YADKIN RIVER AT COOLEEMEE, NC 36 569 High Rock
02120500 THIRD CREEK AT CLEVELAND, NC 31 87.4 High Rock
02120780 SECOND CREEK NEAR BARBER, NC 40 118 High Rock
02121500 ABBOTTS CREEK AT LEXINGTON, NC 30 174 High Rock
02122500 YADKIN RIVER AT HIGH ROCK, NC 20 4000 High Rock
02123500 UWHARRIE RIVER NEAR ELDORADO, NC 33 342 Tillery
02123567 DUTCHMANS CREEK NR UWHARRIE, NC 21 3.44 Tillery

2 Finalized Inflow Data Development

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Site
Number Site Name #
Years
Drainage
Area
(sq. mi.)
OASIS Model
Watersheds*
0212393300 W. BR ROCKY R B MTH OF S PRONG R NR
CORNELIUS, NC 14 20.8 Blewett Falls
02124080 CLARKE CREEK NEAR HARRISBURG, NC 15 21.9 Blewett Falls
0212414900 MALLARD CR BL STONY CR NR HARRISBURG, NC 24 34.6 Blewett Falls
0212419274 CODDLE CR AT SR 1612 NEAR DAVIDSON, NC 16 22.7 Blewett Falls
0212427947 REEDY CREEK AT SR 2803 NR CHARLOTTE, NC 11 2.5 Blewett Falls
0212433550 ROCKY R AB IRISH BUFFALO CR NR ROCKY RIVER,
NC 17 278 Blewett Falls
02125000 BIG BEAR CR NR RICHFIELD, NC 56 55.6 Blewett Falls
02126000 ROCKY RIVER NEAR NORWOOD, NC 89 1372 Blewett Falls
02127000 BROWN CREEK NEAR POLKTON, NC 34 110 Blewett Falls
02128000 LITTLE RIVER NEAR STAR, NC 65 106 Blewett Falls
02129000 PEE DEE R NR ROCKINGHAM, NC 89 6863 D/S of
Blewett Falls
02131000 PEE DEE RIVER AT PEEDEE, SC 89 8830 D/S (South
Carolina)
* Watershed in the OASIS model schematic is considered as the catchment area at the dam site for major
mainstem reservoirs as color coded in Figure 3 above.

A map with USGS gages used for all the inflow nodes for the combined model is shown in Figure 4. The
node locations also include other information such as annual average flow and 7-day minimum average
flow values estimated by USGS in 2002.

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Figure 4: Map of gages used as inflow nodes in the Yadkin-Pee Dee and Lumber River Basins3

2.3.2. Water Use and Demand
In the model, there are three general classifications of water users – municipal, industrial and
agricultural. Municipal current water uses and future demand data for a Public Water Supply System
(PWSS) or local government was collected from their Local Water Supply Plan (LWSP). Water Withdrawal
and Transfer Registration (WWATR) datasets were collected for other municipal and industrial data
reports. The WWATR industrial classification includes all registered agricultural (turf, hatchery, etc.),
energy, industrial, mining, and recreational uses. Agricultural data for cultivated farm irrigation and

3 Modeling the Yadkin-Pee and Lumber River Basin Operations with OASIS

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animal farm uses are collected at county level and then allocated to watershed levels based on the
percent of land. The North Carolina Department of Agriculture & Consumer Services, Agriculture
Statistics Division, is required to collect annual information from farmers who withdraw more than
10,000 gallons per day (GPD). Individual responses remain confidential and are only used in combination
with other reports, including produce and livestock totals. Operations that withdraw more than 1.0 MGD
are required to register and report water use to DWR through the WWATR program. The details on the
water use data is available in the model development “Data Collection Report – Yadkin-Pee Dee and
Lumber River Basins”.
2.3.3. Reservoirs and Operation Information
The Yadkin-Pee Dee River basin has several major lakes and reservoirs created for water supply, power
generation, flood control, conservation of fish and wildlife, and recreational purposes. These reservoirs
were created in the mainstem as well as in the tributaries by several entities to meet their purposes.
Some of the operators are the US Army Corps of Engineers (USACE), Winston-Salem, Asheboro, Water
and Sewer Authority of Cabarrus County (WSACC), Duke Energy, Cube Hydro, etc. Table 4 provides a
complete list of all the reservoirs in the Yadkin-Pee Dee River basin with associated model nodes. It also
includes corresponding drainage areas, operating pool levels and storage volume at the operating levels.
Several of the reservoirs have minimum release requirements with either constant or seasonal and/or
tiered variations.
As per the model development report “The reservoirs are operated following a set of operating rules.
The most common operating rules are for storing water in reservoirs versus releasing the water to meet
local demands or minimum releases, and these are reflected by the weighting scheme. …. The more
complex form of operating rules is associated with hydropower production and drought management
protocol that determine the demand reductions based on reservoir levels/storage or river flows”4. The
municipal systems follow a set of rules which is described in the drought management protocol agreed
to in the hydropower licenses for the mainstem projects known as Low Inflow Protocol (LIP) as well as
their individual Water Shortage Response Plans (WSRP), whichever is applicable depending on the water
source(s). The Federal Energy Regulatory Commission (FERC) renewed operating licenses in 2015-2017
that will allow hydroelectric facilities owned/operated by Cube Hydro and Duke Energy in central North
Carolina to continue producing electricity until 2055. Note that this version of the Yadkin-Pee Dee and
Lumber River basin model is not set up for detailed hydro operations. For the planning purposes, the
model assumes the operations are maintained at guide curve. A reservoir guide curve or rule curve is the
set of reservoir elevation(s) to be used as target operating level or range of levels.

4 https://edocs.deq.nc.gov/WaterResources/DocView.aspx?dbid=0&id=2743764&cr=1

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Table 4: Yadkin-Pee Dee River Basin Reservoir Information used in the Model

Note: * Added as lag reservoir without any physical data in the model

i. W. Kerr Scott Reservoir
W. Kerr Scott Reservoir is the first impoundment located in Wilkes County on the Yadkin River. USACE
manages the dam and the reservoir. More information on water control is available in the W. Kerr Scott
Dam and Reservoir Master Plan. The purposes served by the W. Kerr Scott Reservoir as per the USACE W.
Kerr Scott Dam and Reservoir Master Plan (USACE 2012) and Water Control Plan (USACE 1993) are:
- Flood Control is the primary objective of the reservoir. The plan of operation for the reservoir is
to maintain a normal pool elevation of 1030 feet-mean sea level (msl). The flood control pool
above elevation of 1030 feet-msl is utilized for flood control. This flood storage, used to provide
upstream and downstream flood control and protection prior to or during storm events, is
optimized by storing and controlled releasing extra water between the elevations of 1030 and
1075 feet-msl within the reservoir and from an additional surcharge storage volume between
the elevations of 1075 and 1102.5 feet-msl.
- Water Supply objective is met using the storage volume within conservation pool between the
elevations of 1,000 and 1,030 feet-msl. This storage volume is reserved for water supply and
Node No Node Name River Segment
OASIS Model
Watershed
Min Release
Requirement
Drainage
Area, sq-mile
Normal Pool
Storage, MG
Operating Pool
Level, ft-msl
10 W. Kerr Scott Reservoir Above W. Kerr Scott W. Kerr Scott Min Release 367 11,941 1030
16 Lag Reservoir*Below W. Kerr Scott W. Kerr Scott
170 Allred Mill Reservoir Ararat R High Rock 32 50 1000
180 JK Boyd Reservoir Ararat R High Rock 67 300 1030
350 5-D Reservoir South Deep Ck High Rock 22 660 1000
380 Salem Lake Salem Ck High Rock Min Release 26.4 1,045 795.6
560 Thom-A-Lex Abbotts Ck High Rock 69.8 1,980 500
570 City Lake Lexington Abbotts Ck High Rock 7.33 100 500
590 High Rock Lake High Rock Lake High Rock Min Release 3973 77,518 623.9
610 Tuckertown Reservoir Tuckertown Tuckertown 4080 13,741 564.7
640 Narrows Reservoir Narrows Reservoir Narrows 4180 46,380 509.8
660 Falls Reservoir Falls Reservoir Falls Min Release 4190 795 332.8
670 Lake Lucas Uwharrie R Tillery Min Release 15.8 1,250 500
676 lake McCrary Uwharrie R Tillery 0.9 40 600
680 Lake Bunch Uwharrie R Tillery 2.5 110 583
690 Lake Reese Uwharrie R Tillery Min Release 103 2,400 600
700 Tillery Reservoir Tillery Basin Tillery Min Release 4640 45,626 278.2
770 Lake Howell Coddle Ck Blewett Falls Min Release 47.6 6,297 650
760 Kannapolis Lake Irish Buffalo Ck Blewett Falls 10.5 1,251 726
780 Lake Fisher Coldwater Ck Blewett Falls 18.9 831 646
790 Lake Concord Coldwater Ck Blewett Falls 4.67 180 658
820 Black Run Ck Reservoir Dutch Buffalo Ck Blewett Falls Min Release 6 178 608
870 Monroe Quarry Richarson Ck Blewett Falls 0.18 80 500
860 Lake Twitty Richarson Ck Blewett Falls 35 481 576.5
840 Lake Monroe Richarson Ck Blewett Falls 9.6 331 540
850 Lake Lee Richarson Ck Blewett Falls 51.4 91 520
920 Blewett Falls Reservoir Rocky R Blewett Falls Min Release 6820 10,068 178.1
950 Roberdale Lake Pee Dee R Pee Dee R 90.8 300 200
980 Hamlet Water Lake Pee Dee R Pee Dee R 2.91 192 200
No Reservoir Data Associated

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minimum release flow. Wilkes County and the City of Winston-Salem withdraw water from this
storage or through releases from the dam, as necessary. A new raw water intake facility is being
planned for the Town of North Wilkesboro to withdraw water from the Yadkin River in 2026
(LWSP 2024).
- Fish and Wildlife Conservation is accomplished by tiered releases to maintain healthy river
conditions downstream. A minimum instantaneous flow is maintained all the time to achieve fish
and wildlife objectives. These objectives also are met by maintaining a relatively stable water
level in the reservoir during spawning seasons and other important times in different aquatic
species’ life cycles (USACE 1993).
- Recreation objective is supported by operating the lake level at elevation of 1030 feet-msl to
the maximum extent possible during main recreation season in all but extremely dry years.
Lake Operation During Low Flows for W. Kerr Scott Reservoir
The 1993 USACE Water Control Plan described how the lake should be operated. The minimum flow
releases during low flows are based on reservoir elevation as well as the observed stage at Yadkin River
at Wilkesboro gage located downstream of the dam. Table 5 lists the minimum flows prescribed at
different reservoir elevation ranges.
Table 5: W. Kerr Scott Reservoir Minimum Releases
W. Kerr Scott Reservoir Elevation,
ft-msl
Minimum Releases,
cfs
Stage at Wilkesboro Gage,
ft
1029 and above 400 2.11
1028 - 1028.99 350 2.01
1027 - 1027.99 300 1.90
1026 - 1026.99 250 1.78
1024 - 1025.99 200 1.66
1023 - 1023.99 150 1.53
1000 – 1022.99 125
Note: Minimum release should not be less than 125 cfs at any time, except during inspection and maintenance
periods.

ii. Downstream Mainstem Reservoirs
There are 27 more reservoirs downstream of the W. Kerr Scott Reservoir on the Yadkin-Pee Dee River
and on the tributaries. High Rock Lake, Tuckertown Lake, Badin Lake (Narrows Reservoir), Lake Tillery and
Blewett Falls Lake are the major reservoirs on the mainstem, known as the chain of lakes, built for
multipurpose objectives. A sixth small two-mile long lake, Falls Reservoir, is located between Badin and
Tillery.

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Lake Operation During Low Flows for Downstream Mainstem Reservoirs
A low flow protocol known as LIP was established for the hydroelectric projects located on the six major
reservoirs mentioned above. LIP established procedures for adjusting operations during periods of low
inflow to the Yadkin and Yadkin-Pee Dee River hydroelectric projects. Cube Hydro operates four chains of
reservoirs – High Rock Lake, Tuckertown Reservoir, Badin Lake (Narrows Reservoir) and Falls Reservoir
known as Yadkin Hydroelectric Projects. Below Falls Reservoir there are two more reservoirs operated
by Duke Energy – Lake Tillery and Blewett Falls Lake also known as Yadkin-Pee Dee Hydroelectric
Projects. Each reservoir has its own operating range of levels or elevations that vary throughout the
months of the year as shown in Table 6. Table 7 shows the summary of LIP triggers established in the LIP
document referred to as Yadkin-Pee Dee LIP. LIP has five drought stages, from Stage 0 to Stage 4. During
low inflow conditions, reservoir releases will be reduced, reservoir operating ranges will be changed, and
PWSS will be required to reduce water withdrawal to percent reductions in response to the LIP
declaration and conditions. Initiation of this LIP is based on analysis of the trigger conditions on the first
day of each month. The High Rock Reservoir water elevation as of midnight between the last day of the
previous month and the first day of the current month will be used in combination with the U.S. Drought
Monitor Three-Month Numeric Average and the Stream Gage Three-Month Rolling Average Flow to
determine the need to declare a Low Inflow Watch or change the stage of Low Inflow Conditions. Table 8
provides the seasonal prescribed flow targets for the reservoirs as per the Yadkin-Pee Dee LIP. More
information and detailed procedures can be found from Yadkin-Pee Dee LIP document.

Table 6: Normal Minimum Elevations for Hydropower Reservoirs in LIP, (Feet USGS datum - NGVD 1929)

Note: NGVD - National Geodetic Vertical Datum

14

Table 7: Summary of LIP Triggers

Note: NME – Normal Minimum Elevation

Table 8: Prescribed LIP Flows (1), Cubic Feet per Second (CFS)

15

iii. Tributary Reservoirs
There are five lakes in the mainstem tributaries operated by the PWSSs. Two of these reservoirs are Lake
Howell operated by Water and Sewer Authority of Cabarrus County (WSACC) and Salem Lake operated
by Winston – Salem. These reservoirs have minimum releases based on the drought management
protocol trigger levels for the respective PWSSs. The other three reservoirs are Lake Lucas, Lake Reese,
and Black Run Reservoir. Those three reservoirs have minimum releases not tied to low flow conditions.
Table 9 provides the minimum release patterns for the five lakes in the tributaries.
Table 9: Tributary Lakes Minimum Release for Drought Triggers
Lakes Trigger Minimum Release, cfs
Lake Howell: WSACC
>=2 2
=1 3
=0 6
Salem Lake: Winston – Salem
>=2 1.1
=1 1.33
=0 1.55
Black Run Reservoir: WSACC 0.2
Lake Lucas: Asheboro 6
Lake Reese: Asheboro 0.5

iv. PWSS - Drought Responses
The PWSSs that rely on hydropower reservoirs are required to follow LIP established for those reservoirs
as well as WSRPs. The PWSSs relying on other reservoirs, rivers or tributaries are required to follow the
WSRPs only. Additionally, LIP applies to the PWSSs withdrawing more than 1 MGD. During the low flow
conditions and declaration of drought stages, the PWSSs are bound to reduce water withdrawals in
response to the low flow conditions or drought stages. Even though the purchasers are required to
follow the seller’s WSRP in real operations, however, to simplify the operation in the model, the
purchasers aren’t set to reduce demand, instead the sellers are set to reduce their demands as scripted
in the model. The exception is water purchases involving IBTs. In general, most would need to reduce
consumption based on the drought management protocol for source system/basin(s). Demand reduction
for any IBT sourced outside of the major river basin isn’t set in the model such as Concord and Union
County. Concord only follows Yadkin-Pee Dee LIP in the model. Union County’s drought responses are
not simulated at all in the model. The PWSSs usually have four to five levels of drought stages. However,
for modeling purposes it is assumed that there are four stages for all the systems. Table 10 provides the
list of the PWSS and the drought response types for each system.

16

Table 10: WSRP Induced Triggers
Municipality Drought
Response Water Sources WSRP Trigger Based on #
Stages % Reduction
WSACC*
Kannapolis WSRP & LIP Rocky River Lake Howell 4 5, 10, 20, 25
Concord**
WSRP, LIP &
Catawba LIP
Albemarle/Rocky
River/Catawba Lake Howell 4
5, 10, 20, 25
Mt Pleasant WSRP & LIP Rocky River Lake Howell 4 5, 10, 20, 25
Union
County**
LIP &
Catawba LIP Lake Tillery Lake Tillery 4
5, 10, 20, 25
Anson
County*** WSRP Pee Dee River Stage @ Intake 4
5, 10, 20, 25
Albemarle WSRP & LIP Tuckertown/Narrows Lake Narrows 4 5, 10, 20, 25
Denton WSRP & LIP Tuckertown Lake Tuckertown 4 5, 10, 20, 25
Montgomery WSRP & LIP Lake Tillery Lake Tillery 4 5, 10, 20, 25
Norwood WSRP Lake Tillery Lake Tillery 4 5, 10, 20, 25
Davidson WSRP Yadkin River Yadkin River 4 5, 10, 20, 25
Lexington WSRP Lake ThomALex Lake Level 4 5, 10, 20, 25
Davie County WSRP Yadkin River Demand/Streamflow% 4 5, 10, 20, 25
Elkin WSRP Big Elkin River Inflow 4 5, 10, 20, 25
King WSRP Yadkin River
YR at Enon Gage
(02115360) Flow 4
5, 10, 20, 25
Mocksville WSRP Hunting Creek Demand/Streamflow% 4 5, 10, 20, 25
Salisbury WSRP Yadkin River
YR at Yadkin College
Gage (02116500) Flow 4
5, 10, 20, 25
Wilkesboro WSRP W. Kerr Scott/Gage
KScott/YR at Wilkesboro
Gage (02112000) 4
5, 10, 20, 25
Winston Salem WSRP W. Kerr Scott/Gage
KScott/Enon Gage
(02115360) 4
5, 10, 20, 25
Monroe WSRP Lake Twitty/Quarry SupplyRemaining@Lakes 4 5, 10, 20, 25
Asheboro WSRP
Lake Lucas/ Bunch/
Reese SupplyRemaining@Lakes 4
5, 10, 20, 25
Mt Airy WSRP
Allred Mill and JK
Boyd Reservoir
Lake Elevation@Stewart
Creek Dam Weir 4
5, 10, 20, 25
* WSACC serves Concord, Kannapolis and Mount Pleasant.
** Concord and Union County IBTs are affected by both Catawba-Wateree (C-W) and Yadkin-Pee Dee (YPD) LIPs in
real operation. C-W LIP is not modeled here. Only YPD LIP is effective. However, Union County is not added as a
Demand Node in the model to simulate the drought responses. Instead, a constant flow value is assigned in the
delivery arc for flows based on the years and permitted amounts.
*** Anson County WSRP isn’t measurable and not modeled.

17

v. Sedimentation
The storage content of any reservoir has multiple zones for operation. As shown in Figure 5, Zone D is
the flood control zone up to the highest level of the reservoir. Zones C and B are for conservation and
water supply purposes. Zone A is the dead storage zone reserved for sedimentation and isn’t used for
water supply purposes. Gradual deposition of sediments raises the dead storage zone level that
eventually reduces the conservation storage volumes or the capacity of the reservoirs over time.
Sedimentation in the reservoirs is a great threat in the Yadkin-Pee Dee River basin.
Figure 5: Diagram of Reservoir Operational Zones and Rule Curves.

vi. Fish Spawning
In-lake fish spawning season starts in April. For enhancement of fish spawning, FERC licenses for Cube
Hydro and Duke Energy limits the operations of hydropower reservoirs to drawdown no more than +/- 1
to 2 ft of water level from the upper rule curves on the spawning dates for the next one month. Table 11
shows the lake level requirements during the fish spawning season as modeled.
Table 11: Fish Spawning Season Requirements as Modeled
Lakes Dates Lake Level, feet- msl Drawdown +/- Limits, ft
High Rock 15 Apr – 15 May 623.9 1
Tuckertown 15 Apr – 15 May 564.7 1
Narrows 15 Apr – 15 May 509.8 1
Falls 15 Apr – 15 May 332.8 1
Tillery* 1 Apr – 15 May 278.2 1.5
Blewett Falls* 15 Apr – 15 May 178.1 2
*Tillery operation is simplified in the model, basing April 1st, not 15th. Blewett Falls operated
differently. It can override the spawning lake level stabilization as needed to meet the minimum flow.

18

2.4. Model Output Options
The hydrologic model can produce a variety of customized output files in a variety of configurations. The
primary outputs include the following:
• Node Flows – daily flows and flow statistics into / out of a node, or through an arc.
• Reservoir - releases, levels, storages volumes and storage percentages.
• Water Use – Water demands, and corresponding adjusted water supplies based on whether the
simulation was completed with or without drought management plans (LIP/WSRP) activated for
the municipal systems.
• Return Flows – from the municipal/industrial water use nodes as a direct return flow or indirect
for sources outside the basin or from other sources.
Other manipulated output options are:
• Demand Shortages – The annual average shortages with and without drought management
plans (LIP/WSRP), largest shortages, longest stretch in number of days when demand was not
met, and number of years which experienced demand shortages.
• Drought Stages – The total number of days the systems were in any stage of drought conditions
and number of days at different drought stages.
• Hydropower – The productions, revenues or revenue losses for low flows.
• Safe Yield – The values for any water supply reservoir.
• Forecasting – The reservoir level or river flow conditions predicted into the future for up to one
year based on observed or real-time hydrology, water use and reservoir operations data (used
for Position Analysis configurations only. More information on Position Analysis is available in the
Modeling Yadkin Pee Lumber River Basin Operations with OASIS report).

19

3. Modeling Results: Basinwide Impact
3.1. Demand Scenarios Modeled
The Yadkin-Pee Dee and Lumber River Basin Hydrologic Model is used to evaluate different demand
scenarios and evaluate the ability of public water systems that rely on surface water from the basin to
meet current demand as well as projected demands. For planning purposes, three demand scenarios
(2019, 2040 and 2070) are considered for evaluation to represent current, short-term and long-term
demands respectively. Current conditions are characterized using 2019 demands, discharges and
operation policies. This base case demand scenario (also known as Simbase Scenario) is based on actual
water usage in 2019 and provides a point of comparison for changes that may result from increasing
water withdrawals to meet increasing water demands in the future. Demand projections for the years
2040 and 2070 are used for the future scenarios. Therefore, the 2040 and 2070 demand scenarios
represent estimates of future demands based on the current visions of how these communities may
develop. This analysis does not evaluate conditions in 2040 or 2070. It evaluates two different levels of
water demands based on historical flows.
3.2. Water Use and Wastewater Discharge
The PWSSs withdraw water as it is available from their respective source(s) for daily demands. After the
water is consumed, wastewater is returned to the same river somewhere downstream or to a different
river which is added to the overall volume of streamflows making it available to the downstream users.
Some water systems rely on a combination of surface water and groundwater or groundwater only but
discharge the wastewater as surface water into a river. Some water systems purchase water from nearby
water systems to fully serve their area or as additional source(s). Those systems have their own
wastewater discharge points or send the wastewater to another system for discharge. This makes the
networking complex for such a large river basin. As the water flows from upstream to downstream the
continuous daily withdrawal and return flow amounts and their relative locations make the accounting
complex to determine whether the PWSSs in the basin have sufficient water in each day. The model
simulates the streamflows and conditions and optimizes the volume of water in daily timestep as it flows
downstream based on the operating rules, weights and priorities set in the model.
The demands or water use from 2019 condition (Simbase scenario) can be compared for different types
of use or at watershed level. Figure 6 compares the surface water demands by the three major types of
uses (municipal, industrial and agricultural). Figure 7 compares the surface water withdrawn in different
watersheds. It is shown that municipal use by PWSS is the major use in this basin, totaling approximately
76% of all the surface water use. High Rock Lake is the most active watershed compared to the other
watersheds. Being the smallest one, Falls watershed has only a tiny withdrawal for agricultural uses.
Overall annual average water use, and wastewater return flows are summarized for the entire basin for
the Simbase scenario and is presented in Table 12. Please note that these values are simulated annual
average adjusted demands with the drought plan ON setting from the specific watershed as a source, not
the actual demand used in demand node as input, which uses sources from several locations and/or
watersheds. These values are comparing the watershed wise withdrawals, not the place where it’s been
consumed. This summary also includes direct wastewater coming from local withdrawals and indirect

20

wastewater from groundwater (if any) or any other sourced outside the basin but consumed and
discharged within the basin. It also shows the three types of water used at different watershed levels.
The demands for the PWSS nodes from the Yadkin-Pee Dee River basin for Simbase, as well as the 2040
and 2070 future demand scenarios are summarized in Table 13. The future demand scenarios are
created based on the projected demands from LWSP data reported for year 2021, including any sales,
contracts and IBTs for the future. The PWSS or municipal total for Simbase in Figure 7 and Table 12 won’t
match Table 13. Table 13 presents the demands as input used for the Yadkin-Pee Dee demand nodes
only, whereas Table 12 lists the watershed-based simulated amounts includes few IBTs going in and out
of the basin and few emergency transfers in-between watersheds as needed.
Figure 6: Comparison of Simulated Annual Average Water Use by Types for Simbase Scenario

Figure 7: Comparison of Simulated Annual Average Water Use by Watershed for the Simbase Scenario

Municipal ,
136.6, 76%
Industrial ,
12.0, 7%
Agricultural,
30.8, 17%
ANNUAL AVERAGE USE, MGD
1.70
107.88
4.99 4.27 0.01
9.74
44.38
6.42
0.00
20.00
40.00
60.00
80.00
100.00
120.00
Annual Average Use, MGD
W. Kerr Scott High Rock Tuckertown Narrows Falls Tillery Blewett Falls Pee Dee

21

Table 12: Simulated Annual Average Adjusted Demand, Delivery and Wastewater Return Flows (WW RF)
for Simbase Scenario

Node
No Node Name Demand TypeSource River Segment Watershed
Annual Avg
Demand, MGD
Annual Avg
Delivery, MGD
WW RF,
MGD
5 Blue Ridge Patterson Mill IND Yadkin R Above W. Kerr Scott W. Kerr Scott 0.23 0.23 0.22
7 W. Kerr Scott Basin Ag Ag W. Kerr Scott Reservoir Above W. Kerr Scott W. Kerr Scott 1.47 1.47
1.70 1.70 0.22
25 Wilkesboro Mun Yadkin R Above Reddies R High Rock 4.61 4.58
35 N Wilkesboro Mun Reddies R Reddies R High Rock 2.68 2.68
55 Louisiana Pacific Intake IND Yadkin R Below Reddies R High Rock 2.35 2.35
115 Jonesville Mun Yadkin R Yadkin R above Elkin Gage High Rock 0.49 0.49
75 Elkin Mun Big Elkin Ck Yadkin R above Elkin Gage High Rock 0.85 0.85
65 Duvaltex IND Yadkin R Yadkin R above Elkin Gage High Rock 0.08 0.08
135 Dobson Mun Fisher R Fisher R High Rock 0.97 0.97
185 Mt Airy Mun Allred Mill and JK Boyd Res Ararat R High Rock 2.02 2.02
205 Pilot Mt Mun Toms Ck Ararat R High Rock 0.3 0.3
345 King Mun Yadkin R Yadkin R above Enon Gage High Rock 1.59 1.58
355 Yadkinville Mun South Deep Ck South Deep Ck High Rock 0.82 0.82
395 Winston Salem Mun Salem Lake Salem Ck High Rock 37.87 37.86
425 Davidson Water Mun Yadkin R
Yadkin R above Yadkin R at
Yadkin College High Rock 10.16 10.16
295 Mocksville Mun Hunting ck Hunting Ck High Rock 0.88 0.88
375 Davie Co Mun Yadkin & S. Yadkin R South Yadkin R High Rock 2.93 2.93
255 Statesville Mun Third ck South Yadkin R High Rock 3.14 3.14
465 Salisbury Mun Yadkin R Yadkin River /S Yadkin R High Rock 9.31 9.31
525 Duke Buck Steam Plant IND Yadkin R Yadkin R High Rock 2.6 2.6
555 Thomasville Mun Thom-A-Lex Abbotts Ck High Rock 2.65 2.65
565 Lexington Mun City Lake Lexington Abbotts Ck High Rock 2.89 2.88
597 High Rock Basin Ag Ag High Rock Lake High Rock Lake High Rock 18.69 18.69
107.88 107.82 148.69
615 Denton Mun Tuckertown Tuckertown Tuckertown 1.26 1.25
617 Tuckertown Basin Ag Ag Tuckertown Tuckertown Tuckertown 0.35 0.35
625 Albemerle - TT portion Mun Tuckertown Tuckertown Tuckertown 3.38 3.38
4.99 4.98 0.58
647 Narrows Basin Ag Ag Narrows Reservoir Narrows Reservoir Narrows 0.14 0.14
625 Albemerle - Narrow Portion Mun Narrows Reservoir Narrows Reservoir Narrows 4.13 4.13
4.27 4.27 0.2
667 Falls Ag Ag Falls Reservoir Falls Reservoir Falls 0.01 0.01
0.01 0.01 0
685 Asheboro Mun Lk Lucas, Bunch, Reese Uwharrie R Tillery 4.72 4.72
705 Montgomery Mun Tillery Tillery Basin Tillery 2.57 2.56
707 Tillery Basin Ag Ag Tillery Tillery Basin Tillery 1.9 1.9
715 Norwood Mun Tillery Reservoir Tillery Basin Tillery 0.55 0.55
9.74 9.73 0.38
775 Kannapolis Mun kannapolis Lk/Lk Howell Irish Buffalo Ck Blewett Falls 3.19 3.07
785 Concord Mun Lk Concord/Lk Fisher Coldwater Ck Blewett Falls 9.57 9.29
825 Mt Plesant Mun DutchBuffalo Ck Dutch Buffalo Ck Blewett Falls 0.92 0.91
845 Flowe Farm IND Rocky R Rocky R Blewett Falls 0.18 0.18
885 Hendrick Aquadale Quarry IND Big Bear Ck Big Bear Ck Blewett Falls 0.28 0.28
855 Monroe Mun lk twitty/Monroe Quarry Richarson Ck Blewett Falls 6.43 6.38
875 ATI Allvac IND Richarson Ck Richarson Ck Blewett Falls 0 0
915 Hendrick Co Sand Co IND Rocky R Rocky R Blewett Falls 0.3 0.3
935 Duke Energy Smith IND Big Bear Ck Rocky R Blewett Falls 4.18 4.18
927 Blewitt Falls Basin Ag Ag Blewitt Falls Reservoir Rocky R Blewett Falls 7.07 7.07
975 Anson Mun Blewitt Falls Reservoir Rocky R Blewett Falls 7.65 7.65
925 Richmond Co Mun Blewitt Falls Reservoir Rocky R Blewett Falls 4.61 4.61
44.38 43.92 79.61
945 Henrick GS Mine IND Pee Dee R Pee Dee R Pee Dee R 1.79 1.79
955 RockingHam Mun Roberdale Lk/City Pond Hitchcock Ck Pee Dee R 2.43 2.43
985 Hamlet Water Lake Mun Hamlet Lake Pee Dee R Pee Dee R 1.07 1.07
987 Pee Dee Basin Ag Ag PD at Stateline Pee Dee R Pee Dee R 1.13 1.13
6.42 6.42 10.15
179.39 178.85 239.83
-60.98
Blewett Falls Watershed
Pee Dee Watershed
Yadkin Pee Dee Total
Total Consumptive Surface Water Use
W. Kerr Scott Watershed
Tuckertown Watershed
Narrows Watershed
Falls Watershed
Tillery Watershed
High Rock Watershed

22

Table 13: Annual Average PWSS Demand Node Inputs for Simbase, 2040 and 2070 Scenarios
Node
No PWSS Name & ID Simbase,
MGD 2040, MGD 2070, MGD
25 Wilkesboro 01-97-025 4.61 5.53 6.02
35 North Wilkesboro 01-97-010 2.68 6.38 6.53
75 Elkin 02-86-020 0.85 1.32 1.34
115 Jonesville 02-99-010 0.49 0.71 0.81
135 Dobson 02-86-030 0.97 0.96 1.05
185 Mt Airy 02-86-010 2.02 3.32 4.27
205 Pilot Mountain 02-86-025 0.30 0.29 0.36
345 King 02-85-010 1.59 1.75 2.26
255 Statesville 01-49-010 3.14 7.89 16.77
465 Salisbury 01-80-010 9.30 14.71 19.73
295 Mocksville 02-30-010 0.88 1.09 1.37
375 Davie County 02-30-015 2.93 4.23 6.15
355 Yadkinville 02-99-015 0.82 0.91 0.95
395 Winston-Salem 02-34-010 37.83 56.67 74.16
425 Davidson Water 02-29-025 10.16 16.76 22.24
555 Thomasville 02-29-020 2.65 2.79 3.12
565 Lexington 02-29-010 2.89 3.56 4.05
775 Kannapolis 01-80-065 4.95 6.29 10.49
615 Denton 02-29-030 1.26 1.83 1.92
625 Albemarle 01-84-010 4.73 10.87 11.05
785 Concord 01-13-010 11.93 25.04 30.17
685 Asheboro 02-76-010 4.72 7.38 9.33
705 Montgomery 03-62-010 2.57 3.64 4.02
715 Norwood 01-84-015 0.55 0.88 1.07
825 Mount Pleasant 01-13-020 0.24 0.56 1.06
855 Monroe 01-90-010 6.61 8.43 13.27
925 Richmond Co. 03-77-109 4.14 4.28 5.02
955 Rockingham 03-77-015 3.25 3.45 3.96
985 Hamlet 03-77-010 1.07 1.18 1.22
975 Anson Co. 03-04-010 4.84 7.39 8.10
865 UNION Co IBT 0.00 19.67 22.95
Total PWSS Demand 134.97 229.77 294.81

23

Sales and Purchases
The major PWSSs have their own intakes to withdraw water directly from the sources (river or reservoir).
Some smaller PWSSs in the basin do not have any direct withdrawal from the sources. Instead, those
smaller systems have purchase – sale contracts with the major systems for their supply or supplement
their supply on an annual average amount. There are two categories of contracts – regular and
emergency. Emergency contracts are used only for emergency cases, and the interconnections are
established but the flows are not modeled as daily supply. However, the regular contracts are used on a
regular basis and included in the model for operation. For future use or scenarios, it is assumed that the
purchasers used their full contract amounts for the contracted years reported in the LWSP.
Typical within the model, demand for any withdrawal node includes sales coming from that node but
doesn’t include the purchases. The purchased amount is included in the respective seller’s node. Most
seller demand nodes include the sale (service area demand + sale); however, some are hardcoded and
put in the arcs as a target flow for the contract amounts coming from the withdrawal/intakes at “Total
Withdrawal” node and are not added into the demand nodes directly. Therefore, the LWSP data is
manipulated to consider the purchase – sale values for correct accounting of the withdrawers.
One example is in Figure 8. Node 0922 is a total withdrawal node withdrawing water from reservoir
0920. The demand node 0925 has the actual demand as an input for Richmond County and a sales
contract amount is included in arc 0922.0955 to supply to node 0955 for Rockingham. Future contract
amounts are added to respective users’ demand amounts for the future scenarios, but not in the
Simbase scenario. Most of the contracts will be active for the years 2030-2070.
Figure 8: Purchase – Sale Connections Example

24

Table 14 shows all purchase – sale contract amounts used as hardcoded in the model. Please note that
Davidson contract to High Point is zero in the table. Davidson interconnection is established in the
model, but there is no transfer of water for the simulation years. Concord and Kannapolis have contract
with Albemarle for 5 MGD, only 2.8 MGD was used for Simbase. The future contract of a total of 10 MGD
from Concord-Kannapolis full IBT amount is distributed as 6 MGD to Concord and 4 MGD to Kannapolis.
Concord will be using their full 6 MGD, however Kannapolis plans to use only 2 MGD, leaving 2 MGD for
future. Therefore, the total through Albemarle is 8 MGD, instead of 10 MGD. Total for all purchases from
all sources for Concord for the future is 14.5 MGD, the highest purchase amount in the basin.
Table 14: Purchase – Sale Contract Amounts in Model, MGD
Seller Purchaser Arc Source Basin - Receiving
Basin
Simbase,
MGD
2040,
MGD
2070,
MGD
Mt Airy Dobson 0182.0135 High Rock - High Rock 0.20 0.20 0.20
Mt Airy Pilot Mt 0182.0205 High Rock - High Rock 0.00 0.25 0.25
Winston
Salem Greensboro 0382.0391 High Rock - Cape Fear 0.30 3.00 3.00
Davidson3 High Point 0422.0435 High Rock - Cape Fear 0.00 0.00 0.00
Albemarle2 Concord 0622.0785 Tillery - Rocky R 2.80 8.00 8.00
Charlotte Concord 0755.0785 Catawba - Rocky R 0.00 5.00 5.00
Kannapolis Concord 0772.0785 Rocky R - Rocky R 0.17 1.50 1.50
Concord Charlotte 0782.0755 Rocky R - Catawba 0.00 1.00 1.00
Concord Kannapolis1 0782.0775 Rocky R - Rocky R 1.30 3.50 3.50
Union
County Monroe 0865.0855 Catawba - Rocky R 0.17 1.99 1.99
Richmond Rockingham 0922.0955 Rocky R - Pee Dee 0.43 0.43 0.43
Anson
County Union County 0972.0855 Rocky R - Catawba/Rocky R 2.10 4.00 4.00
Anson
County Richmond 0972.0925 Rocky R - Pee Dee 0.71 0.80 0.80
Total in Contract 8.18 29.67 29.67
1: Kannapolis has two contracts. 1.5 MGD regular and 4 MGD IBT through Concord from 10 MGD total from
Albemarle.
2: Concord and Kannapolis currently have a contract with Albemarle for 5 MGD. Part of this water is
allocated to Concord (60% or 3 MGD) and the remainder is allocated to Kannapolis (40% or 2 MGD). The
future supply of 3 MGD from Albemarle is the remainder of the allocation for Concord to bring the total
Yadkin transfer to 6 MGD. However, Kannapolis will use only 2 MGD of its total 4MGD allocation from IBT
[Note 1], however Concord will use its full 6MGD. So, total from Albemarle is 6 +2=8 MGD, leaving 2 MGD
remaining from 10 MGD IBT for Kannapolis's future source.
3: Davidson future connection is established in the model, but no water supply set yet.

25

Interbasin Transfer (IBT)
There are four IBT basins in the Yadkin-Pee Dee River basin as shown in Figure 1. As of 2024, there are
four IBT certificates regulating large surface water transfers outside or inside of the Yadkin-Pee Dee River
basin. Two of them are sourced from outside and the Yadkin-Pee Dee River basin is the receiving basin.
For the other two, the Yadkin River IBT basin is the source basin. A list of all the IBTs is published in the
2022 Yadkin-Pee Dee River Basin Plan and shown here in Table 15. More detailed information on IBTs are
available in the Yadkin-Pee Dee basin plan (Chapter 6). Among the four IBTs, Union County received the
latest certificate. Union County (ID 01-90-413) was awarded an IBT amount of 23 MGD average day over
a maximum month in the future to supply into the Rocky River IBT basin’s Union County’s service area
from the Yadkin River IBT basin. Union County serves 40% in Rocky River IBT basin of Yadkin River IBT
basin and 60% in Catawba IBT basin. The breakdown of the expected supply and year online is shown in
Table 16. Scenarios 2040 and 2070 include the projected IBT amount in the model.
Table 15: Yadkin Pee Dee River Basin Interbasin Transfer Certificates5

5 Yadkin-Pee Dee basin plan (Chapter 6)

26

Table 16: Union County IBT Future Sources as Modeled

3.3. Outputs – Changes in Water Availability and Reliability
As the hydrologic model produces a variety of output files in a variety of configurations, it is very
important to communicate the output options along with the assumptions and the purpose of the
analysis. If not used or interpreted correctly, the output values will be misleading. The user can further
analyze the output data and evaluate the conditions and potential impacts. It should be kept in mind
that the assumptions are the same for all runs, only demands and operating conditions are changed for
future runs. The results are compared with Simbase scenario results. This section summarizes the
impacts or changes in water availability.
As part of the Session Law 2010-143, the hydrologic model is designed to simulate the flows of each
surface water resources within the basin that is identified as a source of water for a withdrawal
registered in response to different variables, conditions and scenarios. The model is specifically designed
to predict the places, times, frequencies, and interval at which any of the following may occur:
1. Yield may be inadequate to meet all needs
2. Yield may be inadequate to meet all essential water uses.
3. Ecological flow may be adversely affected.
Please note that the use of ecological flows in the hydrologic models is on hold due to a resolution passed
by the NC Environmental Management Commission (EMC) in 2014 to resolve its concerns.
To answer the yield questions, the model shall determine the yield of water sources from reservoirs and
run-of-river intakes. For modeling and analysis purposes the following are a few definitions used:
• All needs will be the water use that is needed to meet demands when no water use restrictions
are required by WSRP. Model is set with Drought Plan OFF.
• Essential water use will be the water use that is needed to meet demands during the periods
when the WSRPs are at the most severe mandatory level of restrictions measures. Model is set
with Drought Plan ON.
Source
Name PWSID Source Type Year Online
Avg Day
Additional
Supply, MGD
Yadkin
River 01-90-413 Surface 2023 9.84
Yadkin
River 01-90-413 Surface 2032 9.84
Yadkin
River 01-90-413 Surface 2044 3.28
23Total Union Co Future IBT

27

The Simbase and other scenarios are initially set with Drought Plan ON, to be consistent with real-time
operations. Drought Plan OFF is an additional simulation for the yield estimate purposes only. Therefore,
six sets of scenarios are compared here regarding the yield questions for the availability of water to meet
all needs or essential uses as required by the session law.
3.3.1. Impacts on PWSSs
a) Shortages – Place, Time, Frequency and Interval of Inadequacy
All needs or essential water use yield adequacy is determined for the water demands by checking for any
deficits that occurred during the period of records of hydrology. As shown earlier in Table 2, there are 51
demand nodes – 31 municipal (MUN), 10 industrial (IND) and eight agricultural (AG) nodes. Out of those
31 MUN demand nodes for PWSSs, 11 PWSSs do not have any WSRP or LIP plan, the other 19 PWSSs
have WSRP and/or LIP for drought management purposes. One node is added as future demand node
without any operation. These different PWSSs nodes are presented in separate tables for the purpose of
this analysis. The following tables summarize the deficits for each scenario set with Drought Plan ON and
Drought Plan OFF.
I. Nodes without a WSRP or LIP:
All Needs and Essential Water Use Shortages
Table 17 provides a list of shortages or deficits identified for the 10 PWSSs located in the mainstem river
or tributaries within the basin that do not have a WSRP or LIP plans. Since these systems don’t have a
WSRP or LIP to adjust their demand or reduce supply, the impacts are the same for both scenario sets
with Drought Plan ON and OFF. The demand and simulated supply through the nodes and arcs from
sources are compared to estimate the shortage (Demand minus Supply). The average shortage here is
estimated only for the days when there were shortages. Any PWSSs with deficits are highlighted in Table
17. There are two PWSSs showing deficits for all three scenarios.
• Yadkinville experienced shortages for a few days and years out of the 90-year period of record.
Notably, the Simbase simulation average deficit of 0.86 MGD shown in Table 17 is more than the
average demand of 0.82 MGD. This occurred because the monthly demand patterns (variations)
resulted in summertime demand being weighted as higher than demand during other times of
the year.
• Rockingham experienced shortages for longer stretches of days, but their system was impacted
for fewer years during the Simbase and 2040 simulations compared to Yadkinville.

28

Table 17: Shortage Summary for PWSSs Nodes without a WSRP or LIP with Drought Plans ON/OFF

NOTE: * - Non-zero deficits calculated as avg of non-zero deficit amounts only
Shortage = Demand – Supply
Anson County’s WSRP is not measurable, so WSRP isn’t considered in the model

II. Nodes with a WSRP and/or LIP:
Essential Needs Water Use Shortages
The PWSSs that follow drought management protocols are grouped together. These systems must
respond to their own WSRP, Yakin-Pee Dee LIP and/or Catawba-Wateree LIP if they receive water from
Catawba River IBT basin through an IBT connection. Note the Catawba basin is not modeled here. That
means during low flow conditions if drought is triggered, the system demands will be curtailed for that
level. As discussed earlier, the systems purchasing water from other systems will not have to curtail their
water use for the amount in the contract. Instead, the seller will curtail their water use. The only
exception is for an IBT where both parties will be curtailing water use. Table 18 summarizes the
shortages for those nodes with Drought Plan ON scenarios. The reduced demand and supply through the
nodes and arcs from sources are compared to the estimated shortage (adjusted for each incremental
drought stages following percent reductions from their respective WSRP and/or LIP). The annual average
shortage (Reduced Demand minus Supply) is estimated for the days when there were shortages. Any
PWSS with deficits are highlighted in Table 18. There are two systems that showed deficits during future
scenarios.
• Asheboro experienced deficits in the future scenario simulations for a few years.
• Concord experienced deficits for longer stretches of days and a considerable number of years in
the 2040 and 2070 simulations compared to other systems in the basin.
035 N Wilkesboro 2.68 0.00 0.00 0.00 0.00 6.38 0.00 0.00 0.00 0.00 6.54 0.00 0.00 0.00 0.00
115 Jonesville 0.49 0.00 0.00 0.00 0.00 0.71 0.00 0.00 0.00 0.00 0.81 0.00 0.00 0.00 0.00
135 Dobson 0.97 0.00 0.00 0.00 0.00 0.96 0.00 0.00 0.00 0.00 1.05 0.00 0.00 0.00 0.00
205 Pilot Mt 0.30 0.00 0.00 0.00 0.00 0.29 0.00 0.00 0.00 0.00 0.36 0.00 0.00 0.00 0.00
255 Statesville 3.39 0.00 0.00 0.00 0.00 7.88 0.00 0.00 0.00 0.00 16.76 0.00 0.00 0.00 0.00
355 Yadkinville 0.82 0.86 3.00 8.00 4.00 0.91 0.86 3.00 9.00 5.00 0.95 0.90 3.00 9.00 5.00
555 Thomasville 2.65 0.00 0.00 0.00 0.00 2.80 0.00 0.00 0.00 0.00 3.13 0.00 0.00 0.00 0.00
925 Richmond Co 4.15 0.00 0.00 0.00 0.00 4.29 0.00 0.00 0.00 0.00 5.03 0.00 0.00 0.00 0.00
955 Rockingham 3.25 1.75 11.00 11.00 1.00 3.45 2.29 27.00 27.00 1.00 3.96 3.15 56.00 113.00 5.00
975 Anson County 4.84 0.00 0.00 0.00 0.00 7.40 0.00 0.00 0.00 0.00 8.11 0.00 0.00 0.00 0.00
985 Hamlet 1.07 0.00 0.00 0.00 0.00 1.18 0.00 0.00 0.00 0.00 1.23 0.00 0.00 0.00 0.00
Avg
Deficit
(MGD)*
Longest
Deficit
(Days)
No of
Years
Demand
Not Met
Out of
90
Total
Deficit
(Days)
Total
Deficit
(Days)
Total
Deficit
(Days)
No of
Years
Demand
Not Met
Out of
90
Avg
Demand
(mgd)
Avg
Deficit
(MGD)*
Longest
Deficit
(Days)
No of
Years
Demand
Not Met
Out of
90
Avg
Demand
(mgd)
Model Scenario Simbase 2040 2070
Model
Node Water Systems
Avg
Demand
(mgd)
Avg
Deficit
(MGD)*
Longest
Deficit
(Days)

29

Table 18: Shortage Summary for WSRP and/or LIP Nodes with Drought ON

NOTE: * - Non-zero deficits calculated as avg of non-zero deficit amounts only
Shortage = Reduced Demand – Supply

All Needs Water Use Shortages
Table 19 summarizes shortages or deficits for the PWSSs nodes for the Drought Plan OFF setup. The
demand and simulated supply through the nodes and arcs from the sources are compared to estimate
the shortage (Demand minus Supply). The average shortage in Table 19 is estimated for the days when
there were shortages. Any PWSSs with deficits are highlighted in Table 19. There are three systems that
show deficits for all three scenarios.
• Asheboro experienced deficits only during the future scenarios for a few years.
• Concord experienced shortages during all three scenario runs. The Simbase simulation had the
largest average deficit compared to the other scenarios. Future scenarios indicate this system
will experience a considerable number of days and years with deficits.
• Monroe experienced deficits only during the 2070 scenario simulation run. Notably, during the
Drought Plan ON setup, Monroe didn’t show any shortage (Table 18).
25 Wilkesboro 4.58 0.00 0 0 0 5.49 0.00 0 0 0 5.97 0.00 0 0 0
75 Elkin 0.85 0.00 0 0 0 1.32 0.00 0 0 0 1.34 0.00 0 0 0
185 Mt Airy 2.02 0.00 0 0 0 3.31 0.00 0 0 0 4.26 0.00 0 0 0
295 Mocksville 0.88 0.00 0 0 0 1.09 0.00 0 0 0 1.37 0.00 0 0 0
345 King 1.58 0.00 0 0 0 1.74 0.00 0 0 0 2.25 0.00 0 0 0
375 Davie Co 2.93 0.00 0 0 0 4.24 0.00 0 0 0 6.16 0.00 0 0 0
395 Winston Salem 37.86 0.00 0 0 0 56.71 0.00 0 0 0 74.21 0.00 0 0 0
425 Davidson Water 10.16 0.00 0 0 0 16.77 0.00 0 0 0 22.25 0.00 0 0 0
465 Salisbury 9.31 0.00 0 0 0 14.72 0.00 0 0 0 19.74 0.00 0 0 0
565 Lexington 2.88 0.00 0 0 0 3.54 0.00 0 0 0 4.04 0.00 0 0 0
615 Denton 1.25 0.00 0 0 0 1.83 0.00 0 0 0 1.91 0.00 0 0 0
625 Albemerle 4.71 0.00 0 0 0 13.82 0.00 0 0 0 14.00 0.00 0 0 0
685 Asheboro 4.72 0.00 0 0 0 7.38 0.72 16 28 1 9.33 0.58 19 63 2
705 Montgomery 2.56 0.00 0 0 0 3.62 0.00 0 0 0 4.01 0.00 0 0 0
715 Norwood 0.55 0.00 0 0 0 0.88 0.00 0 0 0 1.07 0.00 0 0 0
775 Kannapolis 4.84 0.00 0 0 0 8.10 0.00 0 0 0 12.18 0.00 0 0 0
785 Concord 11.65 0.00 0 0 0 20.04 0.64 34 1959 54 25.01 3.62 86 7598 88
825 Mt Plesant 0.24 0.00 0 0 0 0.55 0.00 0 0 0 1.05 0.00 0 0 0
855 Monroe 6.55 0.00 0 0 0 8.16 0.00 0 0 0 10.92 0.00 0 0 0
Model
Node Water Systems
Avg
Reduced
Demand
(mgd)
Avg
Deficit
(MGD)
Longest
Deficit
(Days)
Model Scenario Simbase 2040 2070
Avg
Deficit
Longest
Deficit
(Days)
No of
Years
Demand
Not Met
Out of 90
Total
Deficit
(Days)
Total
Deficit
(Days)
Total
Deficit
(Days)
No of
Years
Demand
Not Met
Out of 90
Avg
Reduced
Demand
(mgd)
Avg
Deficit
Longest
Deficit
(Days)
No of
Years
Demand
Not Met
Out of 90
Avg
Reduced
Demand
(mgd)

30

Table 19: Shortage Summary for WSRP/LIP Nodes with Drought OFF

NOTE: * - Non-zero deficits calculated as avg of non-zero deficit amounts only
Shortage = Demand – Supply

Although not presented alongside the PWSS shortages, shortages for industrial and agricultural use
categories are estimated as well; however, these shortages were equal to zero for all runs and therefore
are not presented here. The variations in the magnitude and durations of the shortages for the PWSSs
can be further explained by checking the drought stages triggered by the model and fluctuations of
simulated level or storage of the reservoirs operated by the respective PWSSs. This analysis is presented
in the following sub-sections.
b) Drought Stages – Depicted and Predicted
Historical Context of Drought - Depicted
The North Carolina Drought Management Advisory Council started monitoring North Carolina drought
conditions evaluated weekly since 2000. The record shows that the Yadkin-Pee Dee River basin was hard
hit twice by drought in the last two decades, first in summer of 2002 and again in fall 2007 as shown in
Figure 9 and Figure 10. December 2007 was the worst time for the recorded drought condition reaching
D4 drought category for greater percentage of area, and basin remained in D2 and/or D3 category for
the longest duration as well. Figure 11 shows the drought map for the entire state.

25 Wilkesboro 4.61 0.00 0 0 0 5.53 0.00 0 0 0 6.02 0.00 0 0 0
75 Elkin 0.85 0.00 0 0 0 1.32 0.00 0 0 0 1.34 0.00 0 0 0
185 Mt Airy 2.02 0.00 0 0 0 3.32 0.00 0 0 0 4.27 0.00 0 0 0
295 Mocksville 0.88 0.00 0 0 0 1.09 0.00 0 0 0 1.37 0.00 0 0 0
345 King 1.59 0.00 0 0 0 1.75 0.00 0 0 0 2.26 0.00 0 0 0
375 Davie Co 2.93 0.00 0 0 0 4.24 0.00 0 0 0 6.16 0.00 0 0 0
395 Winston Salem 37.87 0.00 0 0 0 56.74 0.00 0 0 0 74.24 0.00 0 0 0
425 Davidson Water 10.16 0.00 0 0 0 16.77 0.00 0 0 0 22.25 0.00 0 0 0
465 Salisbury 9.31 0.00 0 0 0 14.72 0.00 0 0 0 19.75 0.00 0 0 0
565 Lexington 2.89 0.00 0 0 0 3.56 0.00 0 0 0 4.06 0.00 0 0 0
615 Denton 1.26 0.00 0 0 0 1.83 0.00 0 0 0 1.92 0.00 0 0 0
625 Albemerle 4.73 0.00 0 0 0 10.87 0.00 0 0 0 11.05 0.00 0 0 0
685 Asheboro 4.72 0.00 0 0 0 7.38 0.72 16 28 1 9.33 0.80 19 75 2
705 Montgomery 2.57 0.00 0 0 0 3.64 0.00 0 0 0 4.02 0.00 0 0 0
715 Norwood 0.55 0.00 0 0 0 0.88 0.00 0 0 0 1.07 0.00 0 0 0
775 Kannapolis 4.95 0.00 0 0 0 6.29 0.00 0 0 0 9.00 0.00 0 0 0
785 Concord 11.93 7.90 55 295 2 25.03 2.79 86 5003 79 30.16 5.61 158 10141 88
825 Mt Plesant 0.24 0.00 0 0 0 0.57 0.00 0 0 0 1.08 0.00 0 0 0
855 Monroe 6.61 0.00 0 0 0 8.43 0.00 0 0 0 13.27 7.89 56 163 6
Model
Node Water Systems
Avg
Demand
(mgd)
Avg
Deficit
(MGD)
Longest
Deficit
(Days)
Model Scenario Simbase 2040 2070
No of
Years
Demand
Not Met
Out of 90
Total
Deficit
(Days)
No of
Years
Demand
Not Met
Out of 90
Avg
Demand
(mgd)
Avg
Deficit
[MGD]
Longest
Deficit
(Days)
Total
Deficit
(Days)
No of
Years
Demand
Not Met
Out of 90
Avg
Demand
(mgd)
Avg
Deficit
[MGD]
Longest
Deficit
(Days)
Total
Deficit
(Days)

31

Figure 9: Upper Pee Dee Percent Area Drought Monitor Categories in 2002

Figure 10: Upper Pee Dee Percent Area Drought Monitor Categories in 2007-2008

Figure 11: North Carolina Drought Monitor Map on December 25, 2007

32

Drought Stages Triggered - Predicted
Even though the model determines drought categories mostly based on reservoir levels and stream
flows, the US drought monitoring depicts drought condition based on other indices such as groundwater,
rainfall, soil moisture content, etc. Therefore, the drought levels depicted in real-time may not be exactly
aligned with the model predicted levels but should follow the similar trend and intensity.
Table 20 presents the summary of drought stages predicted by the model runs for the PWSSs with WSRP
and/or LIP. The results are highlighted for higher duration of drought stages and number of years
impacted. By comparing the previously estimated shortages to drought stages for the same systems, it
appears the WSRP and LIP triggered by the different drought stages are minimizing the magnitude,
frequency and duration of shortages. Although drought conditions are triggered for many PWSSs at
durations of a month or more with many systems experiencing sustained drought conditions for many
years, the reduced demands didn’t result in widespread deficit impacts or persistent shortages over
numerous years for many of the PWSSs. Notably, the WSACC three PWSSs and seven additional PWSSs
showed stretches of drought stages for almost the entire period of record for all three scenario runs.
Here is the list of the systems evaluated based on the availability or combined impacts:
• WSACC serves raw water to three systems (Concord, Kannapolis and Mt Pleasant). The main water
source is Lake Howell, WSRPs are based on Lake Howell useable storage volume and reservoir inflow.
These systems have multiple sources from multiple basins; therefore, three sets of drought protocols
are applicable here – WSRPs, Yakin-Pee Dee LIP and Catawba-Wateree LIP for its potential IBT
amount from Charlotte Water.
o Concord is the hard-hit system among all systems. Its shortages for both drought plan ON
and OFF setup presented in Table 18 and Table 19 are aligned with drought stages in Table
20. Their Simbase simulation shortages are more than their future scenario shortages for the
Drought Plan OFF run. The potential IBT from Charlotte Water supplements Concord’s water
supply for future runs, even though it is still in shortage due to higher demands and in real
time operation the supply will be curtailed based on Catawba-Wateree LIP status. Concord’s
delivery was very low due to unavailability of water from the sources during the 2002
drought. Simulated Lake Howell water level and storage volume went to zero and remained
at that level for months during that period.
o Kannapolis has relatively smaller withdrawals than Concord. They receive water from three
different sources and show no shortages even though they experienced drought conditions.
o Mt Pleasant has comparatively smaller withdrawals and shows no shortages even during
drought conditions.
• Monroe shows a higher deficiency in 2070 with higher stages of droughts for the longest durations
amongst all systems for all runs. The simulation started in drought conditions and remained above
the Stage 1 drought levels for the entire 2070 run. Since their WSRP is based on number of days
remaining in storage, 5% reduction in storage for evaporation and 150 MG less storage for
inaccessibility due to intake, the system triggers more frequently. Monroe withdraws water from
Lake Monroe, Lake Lee, Lake Twitty and Monroe Quarry. Since 2014, Monroe also has had an IBT
contract with Union County for 1.99 MGD, which will be used for future runs. However, the system

33

storage dropped to zero for many years in the 2070 run as shown in Figure 18. Additionally, Monroe
faces sedimentation issues for its reservoirs.
• Asheboro didn’t trigger their WSPR for the 2040 run but they are showing shortages. Since their
WSRP didn’t trigger, demand reductions weren’t in effect and therefore Asheboro’s reduced demand
and regular demand were the same. Drought triggers for Stage 1 and Stage 2 did occur in the 2070
run, but demand reduction didn’t prevent shortages.
Table 20: Summary of Drought Stages for the Yadkin-Pee Dee PWSSs with WSRP and/or LIP

* Norwood uses <1 MGD, not bound by LIP
** Monroe WSRP is based on days remaining in storage and 150 MG less storage for inaccessibility due to intake.
*** Mt Airy triggers are tied to elevation through weir in Stewarts' Creek Dam, with max elevation of 1030 ft.
Stage1 Stage 2 Stage 3 Stage 4 Stage 1 Stage 2 Stage 3 Stage 4 Stage 1 Stage 2 Stage 3 Stage 4
Simbase 42.01%2.21%0.93%0.19%566 184 153 61 90 6 3 1 98.9%
Demand 2040 42.07%3.81%0.93%0.19%590 274 153 61 90 11 3 1 98.9%
Demand 2070 42.28%4.62%1.52%0.35%663 589 232 103 90 14 4 1 98.9%
Simbase 3.78%1.79%0.93%0.19%214 184 153 61 12 6 3 1 13.2%
Demand 2040 3.90%1.80%0.93%0.19%214 184 153 61 13 6 3 1 14.3%
Demand 2070 3.91%1.80%0.93%0.19%214 184 153 61 13 6 3 1 14.3%
Simbase 3.63%1.77%0.93%0.19%214 184 153 61 10 5 3 1 11.0%
Demand 2040 3.72%1.77%0.93%0.19%214 184 153 61 10 5 3 1 11.0%
Demand 2070 3.84%1.77%0.93%0.19%214 184 153 61 10 5 3 1 11.0%
Simbase 0.00%0.00%0.00%0.00%0 0 0 0 0 0 0 0 0.0%
Demand 2040 0.00%0.00%0.00%0.00%0 0 0 0 0 0 0 0 0.0%
Demand 2070 0.00%0.00%0.00%0.00%0 0 0 0 0 0 0 0 0.0%
Simbase 3.63%1.77%0.93%0.19%214 184 153 61 10 5 3 1 11.0%
Demand 2040 3.72%1.77%0.93%0.19%214 184 153 61 10 5 3 1 11.0%
Demand 2070 3.72%1.77%0.93%0.19%214 184 153 61 10 5 3 1 11.0%
Simbase 0.10%0.05%0.02%0.00%11 5 4 0 2 2 2 0 2.2%
Demand 2040 0.10%0.06%0.02%0.00%11 6 4 0 2 2 2 0 2.2%
Demand 2070 0.08%0.04%0.00%0.00%7 5 1 0 2 2 1 0 2.2%
Simbase 3.79%1.89%0.98%0.21%214 184 153 61 13 8 5 3 14.3%
Demand 2040 4.05%1.99%1.06%0.29%214 184 153 61 17 12 6 3 18.7%
Demand 2070 4.21%2.17%1.15%0.33%214 184 153 61 23 14 9 4 25.3%
Simbase 0.06%0.00%0.02%0.00%12 0 7 0 1 0 1 0 1.1%
Demand 2040 0.09%0.00%0.04%0.02%13 0 10 7 1 0 1 1 1.1%
Demand 2070 0.19%0.00%0.07%0.04%15 0 13 10 5 0 1 1 5.5%
Simbase 0.24%0.23%0.19%0.13%36 27 22 21 2 4 4 4 4.4%
Demand 2040 0.24%0.23%0.19%0.13%36 27 22 21 2 4 4 4 4.4%
Demand 2070 0.24%0.23%0.19%0.13%36 27 22 21 2 4 4 4 4.4%
Simbase 10.47%1.38%0.00%0.15%162 48 0 24 55 14 0 2 60.4%
Demand 2040 10.93%1.57%0.00%0.14%163 48 0 22 60 17 0 2 65.9%
Demand 2070 11.30%1.65%0.00%0.12%164 47 0 11 61 17 0 2 67.0%
Simbase 0.00%0.00%0.00%0.00%1 0 0 0 1 0 0 0 1.1%
Demand 2040 0.02%0.00%0.00%0.00%5 0 0 0 1 0 0 0 1.1%
Demand 2070 0.04%0.00%0.00%0.00%8 0 0 0 1 0 0 0 1.1%
Simbase 0.07%0.00%0.00%0.00%6 0 0 0 1 0 0 0 1.1%
Demand 2040 0.08%0.00%0.00%0.00%7 0 0 0 2 0 0 0 2.2%
Demand 2070 0.07%0.00%0.00%0.00%6 0 0 0 2 0 0 0 2.2%
Simbase 13.30%1.03%0.01%0.00%223 69 3 0 57 8 1 0 62.6%
Demand 2040 13.33%1.13%0.06%0.00%223 69 9 0 57 8 3 0 62.6%
Demand 2070 13.39%1.39%0.22%0.00%223 116 24 0 57 8 4 0 62.6%
Simbase 0.81%0.00%0.00%0.00%46 0 0 0 10 0 0 0 11.0%
Demand 2040 0.82%0.00%0.00%0.00%46 0 0 0 11 0 0 0 12.1%
Demand 2070 0.80%0.00%0.00%0.00%36 0 0 0 11 0 0 0 12.1%
Simbase 10.07%4.21%0.86%0.00%226 199 134 0 54 29 8 0 59.3%
Demand 2040 36.89%18.44%3.40%0.00%287 261 190 0 88 70 25 0 96.7%
Demand 2070*0.00%99.91%69.62%9.94%0 32841 633 224 0 91 91 57 100.0%
Simbase 0.00%0.00%0.00%0.00%0 0 0 0 0 0 0 0 0.0%
Demand 2040 0.00%0.00%0.00%0.00%0 0 0 0 0 0 0 0 0.0%
Demand 2070 0.36%0.03%0.00%0.00%80 10 0 0 3 1 0 0 3.3%
Simbase 0.01%0.01%0.00%0.02%4 4 0 3 1 1 0 1 1.1%
Demand 2040 0.01%0.03%0.01%0.05%2 7 2 8 1 2 2 3 3.3%
Demand 2070 0.04%0.00%0.00%0.10%4 0 1 9 4 0 1 3 6.6%
Asheboro
Mt Airy***
Wilkesboro
Winston Salem
Monroe**
King
Mocksville
Salisbury
Lexington
Davie Co
Elkin
Norwood*
Montgom
Davidson
WSACC (Serves
Concord, Kannapolis
& Mt Plesant)
Albemerle
Denton
PWSS Name Scenario
% of Days in Drought Longest Days in Drought No of Yrs in Drought % of Yrs
in any
Drought

34

3.3.2. Impacts on Reservoirs
a) Elevation and Storage
Reservoirs are operated based on drought conditions and/or season. Reservoir storage and levels drop
with reduced inflows, increased water demands, higher evaporation and gradual sedimentation. Some of
the impacts on tributary water supply reservoirs are discussed here.
Asheboro Lakes: Asheboro’s water supply sources are Lake Reese (node 0690), Lake Lucas (node 0670),
Lake Bunch (node 0680) and Lake McCrary (node 0676). However, the main sources are 10% from Lake
Lucas and 90% from Lake Reese. Asheboro’s WSRP is based on storage contents in these reservoirs.
Drought triggers occur when the system’s combined storage is below <60% [<190 days of supply]. Lake
Lucas’ storage capacity is almost half of Lake Reese and experiences larger fluctuation in water levels at a
higher frequency. It reached zero percent storage during the 2002 drought as shown in Figure 12. The
elevation duration plot in Figure 13 shows about 60% of the time the elevations were below full pool
level of 500 ft-msl. The minimum releases through the dam were also impacted by the low flow
conditions as shown in Table 21.
Concord Lakes: Concord withdraws water from Lake Howell (node 0770), Lake Concord (node 0790) and
Lake Fisher (node 0780). Lake Howell is the primary source, representing 74 percent of the total useable
storage for the combined reservoir system. Their WSRP is based on storage contents and inflow to Lake
Howell. Lake Concord with Drought Plan On and OFF both options show same lake level fluctuations
(Figure 16). Concord gets constant supply through contract from Albemarle.
o Drought Plan OFF - Concord water delivery was very low due to the unavailability of water from their
sources during the 2002 drought. Lake Howell water level and storage percent went to bottom of the
lake at 615 ft at dead or zero storage and remained at that level for months during that period as
shown in Figure 14 and Figure 15. Lake Concord storage also dropped to bottom of the lake at 641 ft
at dead or zero storage for the 2070 scenario run as shown in Figure 16.
o Drought Plan ON – Lake Howell didn’t go to its lowest level as the drought plan was in effect and
that reduced the withdrawals and minimum releases through the dam as shown in Figure 14 and in
Table 21.
WSACC serves Concord, Kannapolis and Mt Pleasant. All together there are five reservoirs serving their
system. Alongside the three Concord lakes (discussed previously), Kannapolis Lake (node 0760) and Black
Run Creek Reservoir (node 0820) are used as water supply sources for WSACC supplying the Kannapolis
and Mt Pleasant water systems. Even though most of the WSACC system’s reservoirs were impacted
during the 2002 drought, only Black Run Creek Reservoir (node 0820) was impacted more in 1994. Figure
17 shows how storage percents were impacted in 1994 and 2002 for the three scenarios for Black Run
Creek Reservoir.
Monroe Lakes: Monroe also has multiple water supply reservoirs including Lake Monroe (0840), Lake
Lee (0850), Lake Twitty (0860) and Monroe Quarry (0870). Lake Twitty is the largest and main supply
source. Figure 18 shows the fluctuations of the Monroe system combined useable storage percentages
for the reservoirs for three runs with Drought Plan ON and 2070 Drought Plan OFF. It is shown that the
reservoirs dropped to low storage level for all runs for almost all the years and 2070 with Drought Plan
OFF and was zero for many months and years including 2008 (pink dotted line).

35

Figure 12: Asheboro System Lake Storage Percentage During 2002 Drought – Demand 2070

36

Figure 13: Asheboro Lake Lucas Elevation Durations for Simbase, 2040 and 2070

37

Figure 14: Lake Howell Elevation Comparison During 2002 Drought – Simbase, 2040 and 2070

Note: Dead storage at 615 ft

38

Figure 15: Lake Howell Storage with Drought Plan On/OFF for Simbase During 2002 Drought

39

Figure 16: Lake Concord Elevation Comparison During 2002 Drought

Note: Dead storage at 641 ft; Drought On/OFF resulted in same lake level fluctuations

40

Figure 17: Storage Percent Comparison for Black Run Creek Reservoir – 1994 and 2002 Drought

41

Figure 18: Useable Storage Percent for Monroe Lakes

Note: 2040 storage remains above Simbase. Monroe has contract for additional supply for 2040, which puts less stress on its reservoirs.

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b) Minimum Flow Releases
• Through Tributary Reservoir Dams
The minimum flow requirements and the lowest minimum flow estimate for the three runs are
summarized for the tributary reservoirs and shown in Table 21.

Table 21: Simulated Lowest Value of Required Minimum Releases Estimates Through Dams for Tributary
Water Supply Reservoirs
Lakes Tiered Requirements Simbase, CFS 2040, CFS 2070, CFS
Lake Lucas* 6 6 0 0
Lake Reese 0.5 0.5 0.5 0.5
Lake Howell 6, 3 & 2 2 2 2
Salem Lake 1.55, 1.33 & 1.1 1.33 1.33 1.33
Black Run Creek 0.2 0.2 0.2 0.2
* 2002 August Min Release was 0 for few day

• Through Main Stem Reservoir Dams
The mainstem reservoir releases are presented separately in the following section.

3.3.3. Overall Performance Measures
Overall performances for the mainstem larger reservoirs are summarized in this section. USACE, Cube
Hydro and Duke Energy operate those reservoirs for multipurpose uses. Some reservoirs have a wide
range of operating elevations where some are operated in a smaller range of elevations. The measures
are grouped by the operators. The criteria are based on the reservoir operation ranges and other
requirements similar to Union County IBT EIS document (Appendix CD-2, page 1219). Tables 22 through
28 present the performance measures for the mainstem reservoirs and LIP summary.

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Table 22: Performance Measure for USACE Reservoir
Performance Measures Criterion Scenarios
USACE Project
W. Kerr Scott Reservoir (Node 0010) Full Pond 1030' Simbase 2040 2070
Elevation - Recreational
Max Elevation Reached Max Elevation Reached, ft 1076 1076 1076
Fluctuation from reservoir guide curve
(EL 1030.0 ft. msl)
% of time reservoir level 1 ft < guide curve (1029 ft) 31.64% 31.67% 31.68%
% of time reservoir level 2 ft < guide curve (1028 ft) 21.04% 21.06% 21.08%
% of time reservoir level 3 ft < guide curve (1027 ft) 13.22% 13.26% 13.31%
Flooding over Normal Pool # of days reservoir level > normal pool (1030 ft) 291 291 291
Elevation - Water Withdrawal/Operation
Critical Intake Level # of days reservoir elevation < operational minimum
elevation (1000 ft) 0 0 0
Lowest Elevation Reached Lowest Elevation, ft 1018.75 1017.86 1015.46
Flow
Min Flow Through Dam # of days flows < min release [125 cfs] 0 0 0
Max Flow Through Dam Max release, cfs 5400 5400 5400
Min Flow reached Wilkesboro Gage Min Flow target at Wilkesboro Gage, 125 cfs 135.64 139.18 138.24

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Table 23: Performance Measure for Cube Hydro – High Rock Lake
Performance Measures Criterion Scenarios
CUBE Hydro Projects
High Rock Lake (Node 0590) Simbase 2040 2070
Elevation – Aesthetics Full Pond 623.9 ft USGS Datum, 655' Yadkin Datum
Max Elevation Reached Max Elevation Reached, ft 623.9 623.9 623.9
Fluctuation from Reservoir Guide Curve
(EL 623.9 ft. msl)
% of time reservoir level 1 ft < guide curve (622.9 ft) 91.23% 91.30% 91.30%
% of time reservoir level 2 ft < guide curve (621.9 ft) 88.34% 88.43% 88.43%
% of time reservoir level 3 ft < guide curve (620.9 ft) 85.43% 85.56% 85.55%
Flooding over Normal Pool # of days reservoir level > normal pool (623.9 ft) 0 0 0
Elevation - Water
Withdrawal/Operation
Critical Intake Level
# of days reservoir < critical level for shallowest water
supply intake (613.9 ft) 120 127 127
# of days reservoir < critical level for hydro production
(599.9 ft) 0 0 0
Lowest Elevation Reached Lowest Elevation, ft 613.13 613.06 613.06
Fish Spawning Season # of years elevation below Target Elevation on April 15 13 12 12
Flow
Min Flow Through Dam Min Flow Through Dam, cfs 155 164 171
Max Flow Through Dam Max release, cfs 8500 8500 8500
Total Outflow from HR Reservoir [LIP
Flows]
Number of days < = 2,000 cfs [Feb 1 - May 15] 723 731 732
Number of days at or below <= 1,500 cfs flow [May 16 -
May 31] 59 61 62
Number of days =< 1,000 cfs flow [June 1 -Jan 31] 913 940 984
Number of days < critical flow (770 cfs) 203 196 192

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Table 24: Performance Measure for Cube Hydro – Tuckertown & Narrows (Badin Lake)
Performance Measures Criterion Scenarios
Tuckertown Reservoir (Node 0610) Simbase 2040 2070
Elevation - Aesthetics Full Pond 564.7 ft USGS Datum, 596 ft Yadkin Datum
Max Elevation Reached Max Elevation Reached, ft 564.7 564.7 564.7
Fluctuation from reservoir guide curve
(EL 564.7 ft. msl) % of time reservoir level 1 ft < guide curve (563.7 ft) 0% 0% 0%
Elevation - Water Withdrawal/Operation
Critical Intake Level # of days reservoir < critical level (560.7 ft. msl) for
shallowest water supply intake 0 0 0
Lowest Elevation Reached Lowest Elevation, ft 563.7 563.7 563.7
Fish Spawning Season # of years elevation below Target Elevation on April 15 0 0 0
Narrows Reservoir (Badin Lake) (Node 0640) Simbase 2040 2070
Elevation - Aesthetics Full Pond 509.8 ft USGS Datum, 541.1 ft Yadkin Datum
Max Elevation Reached Max Elevation Reached, ft 509.8 509.8 509.8
Fluctuation from reservoir guide curve (EL
509.8 ft. msl)
% of time reservoir level 1 ft < guide curve (508.8) 80.7% 80.9% 80.9%
% of time reservoir level 2 ft < guide curve (507.8) 5.0% 5.6% 5.7%
% of time reservoir level 3 ft < guide curve (506.8) 0.78% 0.94% 0.95%
Elevation - Water Withdrawal
Critical Intake Level # of days reservoir < critical level (486.8 ft. msl) for
shallowest water supply intake 0 0 0
Lowest Elevation Reached Lowest Elevation, ft 502.7 502.6 502.6
Fish Spawning Season # of years elevation below Target Elevation on April 15 0 0 0

46

Table 25: Performance Measure for Cube Hydro – Falls Reservoir
Performance Measures Criterion Scenarios
Falls Reservoir (Node 0660) Simbase 2040 2070
Elevation - Aesthetics Full Pond 332.8 ft USGS Datum, 364 ft Yadkin Datum
Max Elevation Reached Max Elevation Reached, ft 332.8 332.8 332.8
Fluctuation from reservoir guide curve
(EL 332.8 ft. msl)
% of time reservoir level 1 ft < guide curve (331.8) 0% 0% 0%
% of time reservoir level 2 ft < guide curve (330.8) 0% 0% 0%
% of time reservoir level 3 ft < guide curve (329.8) 0% 0% 0%
Elevation - Water Withdrawal
Critical Intake Level # of days reservoir < critical level (322.8 ft. msl) for shallowest
water supply intake 0 0 0
Lowest Elevation Reached Lowest Elevation, ft 331.8 331.8 331.8
Fish Spawning Season # of years elevation below Target Elevation on April 15 0 0 0
Flow
Min Flow Through Dam Min Flow Through Dam, cfs 770 770 770
Max Flow Through Dam Max release, cfs 8400 8400 8400
Total Outflow from Falls Reservoir [LIP
Flows]
Number of days < = 2,000 cfs [Feb 1 - May 15] 625 660 662
Number of days at or below <= 1,500 cfs flow [May 16 - May 31] 81 89 90
Number of days =< 1,000 cfs flow [June 1 -Jan 31] 1,122 1273 1313
Number of days < critical flow (770 cfs) 0 0 0

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Table 26: Performance Measure for Duke Energy – Lake Tillery
Performance Measures Criterion Scenarios
Duke Energy Projects
Lake Tillery (Node 0700) Simbase 2040 2070
Elevation - Aesthetics Full Pond 278.2 ft USGS Datum
Max Elevation Reached Max Elevation Reached, ft 279.0 279.0 279.0
Fluctuation from full pond
elevation (EL 278.2 ft. msl)
% of time reservoir level 1 ft < Full Pond (277.2ft) 0.04% 0.06% 0.06%
% of time reservoir level 2 ft < Full Pond (276.2ft) 0% 0% 0%
% of time reservoir level 3 ft < Full Pond (275.2ft) 0% 0% 0%
Elevation - Water
Withdrawal/Operation
Critical Intake Level
# of days reservoir < critical level for shallowest water supply
intake (268.2 ft) 0 0 0
# of days reservoir < critical level for hydro production (drop 70 ft,
202.2 ft) 0 0 0
Lowest Elevation Reached Lowest Elevation, ft 276.90 276.79 276.77
Fish Spawning Season # of years elevation below Target Elevation on April 1 15 14 15
Flow
Min Flow Through Dam Min Flow Through Dam, cfs 330 330 330
Max Flow Through Dam Max release, cfs 18000 18000 18000

48

Table 27: Performance Measure for Duke Energy – Blewett Falls Reservoir
Performance Measures Criterion Scenarios
Duke Energy Projects
Blewett Falls Lake (0920) Simbase 2040 2070
Elevation - Aesthetics Full Pond 178.1 ft USGS Datum
Max Elevation Reached Max Elevation Reached, ft 182.3 182.3 182.3
Fluctuation from reservoir full pond
elevation (EL 178.1 ft. msl)
% of time reservoir level 1 ft < Full Pond (177.1 ft) 69.1% 69.3% 69.3%
% of time reservoir level 2 ft < Full Pond (176.1 ft) 61.9% 62.1% 62.2%
% of time reservoir level 3 ft < Full Pond (175.1 ft) 1.6% 1.9% 1.8%
Fluctuation from reservoir normal
minimum elevation (EL 172.1 ft. msl)
% of time reservoir level 1 ft < NME (171.1 ft) 0.03% 0.04% 0.04%
% of time reservoir level 2 ft < NME (170.1 ft) 0.02% 0.02% 0.02%
% of time reservoir level 3 ft < NME (169.1 ft) 0.01% 0.01% 0.01%
Elevation - Water Withdrawal
Evaluate days of restricted operation
at lake-located intakes
Number of days reservoir elevation below critical level
(168 ft. msl) for shallowest public water supply intake
operation
0 0 0
Lowest Elevation Reached Lowest Elevation, ft 169.24 168.28 168.42
Flow
Min Flow Through Dam Min Flow Through Dam, cfs 925 925 925
Max Flow Through Dam Max release, cfs 9,200 9,200 9,200
Total Outflow from Blewett Falls
Reservoir [LIP Flows]
Number of days < = 2,400 cfs [Feb 1 - May 15] 145 148 150
Number of days at or below <= 1,800 cfs flow [May 16 -
May 31] 118 122 123
Number of days =< 1,200 cfs flow [June 1 -Jan 31] 1,159 1,236 1236
Number of days =< critical flow (925 cfs) 34 37 37

49

Table 28: Performance Measure for LIP - Drought Management
LIP - Drought Management Simbase 2040 2070
LIP Drought Stage
Percent of time in Normal Conditions 87% 87% 87%
Number of years attaining LIP Stage 0 15 16 16
Number of years with more than 60 days in LIP Stage 0 4 4 4
Number of years attaining LIP Stage 1 10 10 10
Number of years with more than 60 days in LIP Stage 1 2 2 2
Number of years attaining LIP Stage 2 5 5 5
Number of years with more than 60 days in LIP Stage 2 1 1 1
Number of years attaining LIP Stage 3 3 3 3
Number of years with more than 60 days in LIP Stage 3 2 2 2
Number of years attaining LIP Stage 4 1 1 1
Number of years with more than 60 days in LIP Stage 4 0 0 0

50

3.3.4. Future Works:
This document mainly focuses on the water supply data for planning purposes and is limited to
appropriate analysis options. There are other separate model set ups and analysis options that can
be performed by users for other interests such as -
- Sedimentation – future scenarios can be created with reduced storages considering future
increasing sedimentation on reservoirs if the appropriate data is available for the impacted
reservoirs in question.
- Safe Yield Analysis – safe yield values can be estimated with proper sedimentation information
for correct estimation.
- Model Sensitivity – for model sensitivity test scenarios with overall reduced (or increased)
percent of inflows can be performed. The model doesn’t support any climate change scenario
set up within itself. However, preprocessed hydrology data for climate change can be used as a
new set of inflows as input.

51

References
Cube Hydro FERC New License for Yadkin Projects, 2016 (previously Alcoa):
https://savehighrocklake.org/FERCdocs/Alcoa40YearLicense.pdf
Duke Energy FERC New License for Yadkin-Pee Dee Projects, 2015: https://www.duke-energy.com/-
/media/pdfs/community/yadkin-pee-dee-order-issuing-new-license-
20150401.pdf?rev=8b9e1a4b5ea8474fbad3365e28aaa567
Hazen and Sawyer, 2021, Yadkin-Pee Dee and Lumber RB OASIS Model Input and Data:
https://www.deq.nc.gov/water-
quality/planning/tmdl/hydrologicmodeling/yadkinpeedeeandlumber/appendix-model-static-input-data-
and-runcode/download
Hazen and Sawyer, 2021. Yadkin-Pee Dee and Lumber RB OASIS Modeling Operations:
https://edocs.deq.nc.gov/WaterResources/DocView.aspx?dbid=0&id=2743764
LIP for Yadkin-Pee Dee River basin, 2007: https://cubecarolinas.com/wp-
content/uploads/2017/03/LIP_Feb_2007.pdf
NCDEQ Yadkin – Pee Dee River Basin Plan, 2022:
https://edocs.deq.nc.gov/WaterResources/Browse.aspx?id=2650300&dbid=0&repo=WaterResources
NCDEQ LWSP: https://www.ncwater.org/wudc/app/lwsp/search.php
NCDEQ WSRP: https://www.ncwater.org/wudc/app/lwsp/search.php
NCDEQ WWATR: https://www.ncwater.org/WUDC/app/WWATR/page
NCDEQ Union County IBT, 2017 : https://www.deq.nc.gov/about/divisions/water-resources/water-
planning/water-supply-planning/interbasin-transfer-certification/regulated-interbasin-transfers/union-
county-interbasin-transfer-certificate
USACE, 2012. W. Kerr Scott Dam and Reservoir Master Plan:
https://www.saw.usace.army.mil/Portals/59/docs/recreation/Master%20Plan/WKerrScott/W.%20Kerr%2
0Scott%20Final%20Master%20Plan_wi.pdf
USACE, 1993. Water Control Manual: W. Kerr Scott Dam and Reservoir Project: Yadkin River Basin, North
Carolina: https://www.deq.nc.gov/water-resources/planning-section/water-supply-planning/kerr-scott-
water-control-manual-1993/open