Chapter 18

Chapter 18
Water Resources

18.1 River Basin Hydrologic Units

Under the federal system, the Roanoke River basin is made up of hydrologic areas referred to as
cataloging units (USGS 8-digit hydrologic units). The Roanoke River basin is made up of five
whole cataloging units: Dan River (NC portion), County Line Creek and Hyco Reservoir, Kerr
Reservoir and Tributaries, Lake Gaston and Smith Creek and Cashie River and Roanoke River.
Cataloging units are further divided into smaller watershed units (14-digit hydrologic units or
local watersheds) that are used for smaller scale planning like that done by NCEEP. There are
123 local watershed units in the basin. Table 18 compares the three systems. A map identifying
the hydrologic units and subbasins can be found in Appendix I.

Table 18 - Hydrologic Subdivisions in the Roanoke River Basin
Watershed Name
and
Major Tributaries
DWQ
Subbasin
6-Digit
Codes
USGS
8-Digit
Hydrologic
Units
USGS
14-Digit Hydrologic Units
Local Watersheds*
Dan River (NC Portion)
Town Fork Creek, Snow Creek, Wolf
Island Creek, Big Beaver Island,
Belews Lake, Mayo River, Smith
River
03-02-01
03-02-02
03-02-03

03010103 170010, 170020, 170030, 180010, 170050,
170040, 180020, 190010, 180030, 190020,
180050, 180040, 210100, 210150, 210200,
220020, 220010, 220030, 220050, 220040,
230010, 230020, 250030, 230040,
Country Line Creek and Hyco Reservoir
Hogans Creek, Country Line Creek,
Hyco Creek, Marlowe Creek, Hyco
River, Mayo Reservoir
03-02-03
03-02-04
03-02-05
03-02-06
03010104 021010, 021020, 021030, 021040, 021050,
021060, 021070, 021080, 032010, 032020,
032030, 040040, 061010, 061020, 061030,
061040, 061050, 061060, 061070, 061080,
061090, 062010, 062020, 063010, 065010
Kerr Reservoir and Tributaries
Grassy Creek, Island Creek, Nutbush
Creek
03-02-06 03010102 161010, 161020, 161030, 161040, 170010,
170020, 170030, 170040, 180010
Lake Gaston and Smith Creek
Sixpound Creek, Deep Creek,
Roanoke Rapids Lake
03-02-07
03-02-08
03010106 031010, 041010, 041020, 041030, 041040,
041050, 041060, 041070, 041080, 041090,
041100
Cashie River and Roanoke River
Roquist Creek, Conoho Creek,
Hardison Mill Creek, Quankey Creek,
Conconnara Swamp, Connaritsa
Swamp, Kehukee Swamp
03-02-08
03-02-09
03-02-10

03010107 080010, 080020, 080040, 080030, 070010,
070030, 070020, 080050, 090020, 070040,
110010, 090010, 090030, 160010, 160011,
160020, 100020, 110020, 100010, 160012,
160050, 160030, 130010, 160040, 160070,
110030, 120010, 160060, 120020, 160071,
160090, 130020, 160110, 160080, 120050,
160130, 120040, 160115, 160120, 160081,
120030, 170020, 130030, 120070, 130040,
150020, 170010, 120060, 140050, 150030,
140040, 150010, 140020, 140030, 140010
* Numbers from the 8-digit and 14-digit column make the full 14-digit HU.
Chapter 18 – Water Resources 167
18.2 Minimum Streamflow

One of the purposes of the Dam Safety Law is to ensure maintenance of minimum streamflows
below dams. Conditions may be placed on dam operations specifying mandatory minimum
releases in order to maintain adequate quantity and quality of water in the length of a stream
affected by an impoundment. The Division of Water Resources, in conjunction with the Wildlife
Resources Commission (WRC), recommends conditions relating to release of flows to satisfy
minimum instream flow requirements. The Division of Land Resources (DLR) issues the
permits. The Federal Energy Regulatory Commission (FERC) licenses all dams associated with
hydropower.

Hydroelectric Dams
There are three operational dams in the Roanoke River basin, which are all located on the
Roanoke River (subbasin 03-02-07, 03-02-08). Information on these three dams is presented
below. In addition, there are two dam projects that are under development both of which are
located on the Mayo River (subbasin 03-02-02).

J.H. Kerr Dam is owned and operated by the U.S Army Corp of Engineers and covers 48,900
acres at an elevation of 300 feet. John H. Kerr project is authorized for recreation, flood control,
hydroelectric power generation, fish and wildlife, and water supply. John H. Kerr is not
regulated for low flow augmentation since the Federal Energy Regulatory Commission (FERC)
assigned that requirement to the two Virginia Power Company projects located downstream.
Kerr Reservoir extends into Mecklenburg, Charlotte and Halifax counties in Virginia and
Granville, Vance and Warren counties in North Carolina.

Gaston and Roanoke Rapids Dam is owned and operated by Dominion North Carolina Power.
These projects are regulated by FERC and have minimum flow requirements per FERC license
number P-2009. The life of the license is forty years and was issued on March 31, 2004 and re-
issued as ‘revised’ on March 4, 2005. Several license requirements are listed in the articles
below:

Article 407. Roanoke River Bypassed Reach Flows.
Notwithstanding, the minimum flow in the bypass shall not be less than 325 cfs.

Article 409. Roanoke Rapids Flow Operating Restrictions.
From December 1 through January 15, the licensee shall maintain a minimum flow of 2,000
cubic feet per second (cfs) if the U.S. Army Corps of Engineers’ (Corps) weekly flow
declaration for the Kerr dam is less than 6,000 cfs, or the daily mean of the weekly declaration
(as defined in Settlement Agreement Article GP2), whichever is less. Notwithstanding, the
licensee shall only release flows less than 2000 cfs pursuant to the provisions of article 405 of
this license and settlement agreement article FL2, Section 4.2. If the Corps’ weekly flow
declaration for the Kerr dam is equal to, or greater than, 6,000 cfs, the licensee shall maintain a
minimum flow of 2,500 cfs.

From January 16 through the end of February, the licensee shall maintain a minimum flow of
2,500 cfs if the Corps’ weekly flow declaration for the Kerr dam is less than 6,000 cfs, or the
daily mean of the weekly declaration (as defined in Settlement Agreement Article GP2),
168 Chapter 18 – Water Resources

whichever is less. Notwithstanding, the licensee shall only release flows less than 2000 cfs
pursuant to the provisions of article 405 of this license and settlement agreement article FL2,
Section 4.2. If the Corps’ weekly flow declaration for the Kerr dam is equal to, or greater than,
6,000 cfs, the licensee shall maintain a minimum flow of 3,000 cfs.

From March 1 through March 31, the licensee shall be afforded up to five days with which to
operate in a peaking mode, provided that peaking operations occur only subject to all of the
following conditions: (1) for no more than three consecutive days; (2) for no more than three
days in any 7-day period; (3) during no more than two weeks during the month of March; (4) for
no more than two days from March 25 through March 31; and (5) provided further that the
Corps’ weekly declaration flow is greater than 3,500 cfs. During peaking operations, the
licensee shall maintain a minimum flow of 3,500 cfs, and maintain an 8,500-cfs flow for 1 hour
as flows are increased from the minimum flow to the generation flow and decreased from the
generation flow to the minimum flow. At all other times, the licensee shall maintain a
continuous flow equal to the daily mean of the Corps’ weekly declaration flow for Kerr Dam (as
defined in Settlement Agreement Article GP2).

From April 1 through June 15, the licensee shall maintain, at all times, a continuous minimum
flow equal to the Corps’ weekly declaration flow for the Kerr dam (as defined in Settlement
Agreement Article GP2), and no change in weekly flow shall exceed 5,000 cfs per hour.

From June 16 through November 30, the licensee shall maintain the following minimum flows:
Time Period Discharge (cfs)
June 16 – June 30 2,800
July 1 – September 15 2,000
September 16 – November 15 1,500
November 16 – November 30 2,000

Under drought conditions, as determined by the Corps’, the licensee shall maintain, between
January 1 and August 31, a minimum flow of 2,000 cfs; and between September 1 and
November 30, a minimum flow of 1,500 cfs; and between December 1 and December 31, a
minimum flow of 2,000 cfs.

For complete license, go to Federal Energy Regulatory Commission (FERC) e-Library,
Advanced Search Page at: http://elibrary.ferc.gov/idmws/search/fercadvsearch.asp and enter
“20050304-3070” in “Accession Number” field.

18.3 Interbasin Transfers

In addition to water withdrawals (discussed above), water users in North Carolina are also
required to register surface water transfers with the Division of Water Resources (DWR) if the
amount is 100,000 gallons per day or more. In addition, persons wishing to transfer two million
gallons per day (MGD) or more, or increase an existing transfer by 25 percent or more, must first
obtain a certificate from the Environmental Management Commission (G.S. 143-215.22I). The
river basin boundaries that apply to these requirements are designated on a map entitled Major
River Basins and Sub-Basins in North Carolina, on file in the Office of the Secretary of State.
These boundaries differ from the 17 major river basins delineated by DWQ.
Chapter 18 – Water Resources 169
In determining whether a certificate should be issued, the state must determine that the overall
benefits of a transfer outweigh the potential impacts. Factors used to determine whether a
certificate should be issued include:

• the necessity, reasonableness and beneficial effects of the transfer;
• the detrimental effects on the source and receiving basins, including effects on water supply
needs, wastewater assimilation, water quality, fish and wildlife habitat, hydroelectric power
generation, navigation and recreation;
• the cumulative effect of existing transfers or water uses in the source basin;
• reasonable alternatives to the proposed transfer; and
• any other facts and circumstances necessary to evaluate the transfer request.

A provision of the interbasin transfer law requires that an environmental assessment or
environmental impact statement be prepared in accordance with the State Environmental Policy
Act as supporting documentation for a transfer petition.

In the Roanoke River basin, the Kerr Lake Regional Water System (KLRWS) is a public water
system serving portions of Vance, Granville, Franklin and Warren counties. The System serves
three bulk customers—the City of Henderson, City of Oxford, and Warren County—which
currently supply water to the Town of Kittrell, Town of Norlina, Town of Warrenton, Town of
Middleburg, Franklin County and the City of Louisburg.

In June 2003, KLRWS submitted an Environmental Assessment (EA) to the North Carolina
Department of Environment and Natural Resources (NCDENR) for the Kerr Lake Water System
Expansion to increase their existing water treatment plant capacity from 10 MGD to 20 MGD.
This EA was granted a Finding of No Significant Impact (FONSI) on June 19, 2003. The
treatment plant has been approved for a higher filter rating, allowing the plant to operate under
special circumstances at 15 MGD or potentially operate at 25 MGD after plant expansion.

A meeting was held at NCDENRs office in Raleigh, NC on February 24, 2004 to review and
prepare the scoping document for the KLRWS Interbasin Transfer petition. The compilation of
key environmental issues and relevant agency comments at this meeting revealed greater clarity
as to the requirements for this petition. Since the magnitude of the impacts from this proposed
project is uncertain at this time, an Environmental Assessment (EA) was chosen as the initial
document format. If, however, the EA concludes that the environmental impacts will be
significant and cannot be fully mitigated, an EIS will be prepared. A determination that an EIS
is required may be made at any time during the EA review process.

For more information on interbasin transfers, visit the website at http://www.ncwater.org or call
DWR at [phone].

18.4 Water Quality Issues Related to Drought

Water quality problems associated with rainfall events usually involve degradation of aquatic
habitats because the high flows may carry increased loadings of substances like metals, oils,
herbicides, pesticides, sand, clay, organic material, bacteria and nutrients. These substances can
be toxic to aquatic life (fish and insects) or may result in oxygen depletion or sedimentation.
170 Chapter 18 – Water Resources

During drought conditions, these pollutants become more concentrated in streams due to reduced
flow. Summer months are generally the most critical months for water quality. Dissolved
oxygen is naturally lower due to higher temperatures, algae grow more due to longer periods of
sunlight, and streamflows are reduced. In a long-term drought, these problems can be greatly
exacerbated, and the potential for water quality problems to become catastrophic is increased.
This section discusses water quality problems that can be expected during low flow conditions.

The frequency of acute impacts due to nonpoint source pollution (runoff) is actually minimized
during drought conditions. However, when rain events do occur, pollutants that have been
collecting on the land surface are quickly delivered to streams. When streamflows are well
below normal, this polluted runoff becomes a larger percentage of the water flowing in the
stream. Point sources may also have water quality impacts during drought conditions even
though permit limits are being met. Facilities that discharge wastewater have permit limits that
are based on the historic low flow conditions that may not be as extreme as future droughts.
During droughts these wastewater discharges make up a larger percentage of the water flowing
in streams than normal and might contribute to lowered dissolved oxygen concentrations and
increased levels of other pollutants.

As streamflows decrease, there is less habitat available for aquatic insects and fish, particularly
around lake shorelines. There is also less water available for irrigation and for water supplies.
The dry conditions and increased removal of water for these uses further increases strain on the
resource. With less habitat, naturally lower dissolved oxygen levels and higher water
temperatures, the potential for large kills of fish and aquatic insects is very high. These
conditions may stress the fish to the point where they become more susceptible to disease and
where stresses that normally would not harm them result in mortality.

These decreased flow conditions create linger retention times and allow algae to take full
advantage of the nutrients present resulting in algal blooms. During the daylight hours, algae
greatly increase the amount dissolved oxygen in the water, but at night algal respiration and die
off can cause dissolved oxygen levels to drop low enough to cause fish kills. Besides increasing
the frequency of fish kills, algae blooms can also cause difficulty in water treatment resulting in
taste and odor problems in finished drinking water.

18.5 Source Water Assessment of Public Water Supplies

18.5.1 Introduction

The Federal Safe Drinking Water Act (SDWA) Amendments of 1996 emphasize pollution
prevention as an important strategy for the protection of ground and surface water resources.
This new focus promotes the prevention of drinking water contamination as a cost-effective
means to provide reliable, long-term and safe drinking water sources for public water supply
(PWS) systems. In order to determine the susceptibility of public water supply sources to
contamination, the amendments also required that all states establish a Source Water Assessment
Program (SWAP). Specifically, Section 1453 of the SDWA Amendments require that states
develop and implement a SWAP to:

ƒ delineate source water assessment areas;
Chapter 18 – Water Resources 171
ƒ inventory potential contaminants in these areas; and
ƒ determine the susceptibility of each public water supply to contamination.

In North Carolina, the agency responsible for the SWAP is the Public Water Supply (PWS)
Section of the DENR Division of Environmental Health (DEH). The PWS Section received
approval from the EPA for their SWAP Plan in November 1999. The SWAP Plan, entitled
North Carolina’s Source Water Assessment Program Plan, fully describes the methods and
procedures used to delineate and assess the susceptibility of more than 9,000 wells and
approximately 207 surface water intakes. To review the SWAP Plan, visit the PWS website at
http://www.deh.enr.state.nc.us/pws/index.htm.

18.5.2 Delineation of Source Water Assessment Areas

The SWAP Plan builds upon existing protection programs for ground and surface water
resources. These include the state’s Wellhead Protection Program and the Water Supply
Watershed Protection Program.

Wellhead Protection (WHP) Program
North Carolinians withdraw more than 88 million gallons of groundwater per day from more
than 9,000 water supply wells across the state. In 1986, Congress passed Amendments to the
SDWA requiring states to develop wellhead protection programs that reduce the threat to the
quality of groundwater used for drinking water by identifying and managing recharge areas to
specific wells or wellfields.

Defining a wellhead protection area (WHPA) is one of the most critical components of wellhead
protection. A WHPA is defined as “the surface and subsurface area surrounding a water well or
wellfield, supplying a public water system, through which contaminants are reasonably likely to
move toward and reach such water well or wellfield.” The SWAP uses the methods described in
the state's approved WHP Program to delineate source water assessment areas for all public
water supply wells. More information related to North Carolina’s WHP Program can be found at
http://www.deh.enr.state.nc.us/pws/swap.

Water Supply Watershed Protection (WSWP) Program
DWQ is responsible for managing the standards and classifications of all water supply
watersheds. In 1992, the WSWP Rules were adopted by the EMC and require all local
governments that have land use jurisdiction within water supply watersheds adopt and implement
water supply watershed protection ordinances, maps and management plans. SWAP uses the
established water supply watershed boundaries and methods established by the WSWP program
as a basis to delineate source water assessment areas for all public water surface water intakes.
Additional information regarding the WSWP Program can be found at
http://h2o.enr.state.nc.us/wswp/index.html.

18.5.3 Susceptibility Determination – North Carolina’s Overall Approach

The SWAP Plan contains a detailed description of the methods used to assess the susceptibility
of each PWS intake in North Carolina. The following is a brief summary of the susceptibility
determination approach.
172 Chapter 18 – Water Resources

Overall Susceptibility Rating
The overall susceptibility determination rates the potential for a drinking water source to become
contaminated. The overall susceptibility rating for each PWS intake is based on two key
components: a contaminant rating and an inherent vulnerability rating. For a PWS to be
determined “susceptible”, a potential contaminant source must be present and the existing
conditions of the PWS intake location must be such that a water supply could become
contaminated. The determination of susceptibility for each PWS intake is based on combining
the results of the inherent vulnerability rating and the contaminant rating for each intake. Once
combined, a PWS is given a susceptibility rating of higher, moderate or lower (H, M or L).

Inherent Vulnerability Rating
Inherent vulnerability refers to the physical characteristics and existing conditions of the
watershed or aquifer. The inherent vulnerability rating of groundwater intakes is determined
based on an evaluation of aquifer characteristics, unsaturated zone characteristics and well
integrity and construction characteristics. The inherent vulnerability rating of surface water
intakes is determined based on an evaluation of the watershed classification (WSWP Rules),
intake location, raw water quality data (e.g., turbidity and total coliform) and watershed
characteristics (e.g., average annual precipitation, land slope, land use, land cover, groundwater
contribution).

Contaminant Rating
The contaminant rating is based on an evaluation of the density of potential contaminant sources
(PCSs), their relative risk potential to cause contamination, and their proximity to the water
supply intake within the delineated assessment area.

Inventory of Potential Contaminant Sources (PCSs)
In order to inventory PCSs, the SWAP conducted a review of relevant, available sources of
existing data at federal, state and local levels. The SWAP selected sixteen statewide databases
that were attainable and contained usable geographic information related to PCSs.

18.5.4 Source Water Protection

The PWS Section believes that the information from the source water assessments will become
the basis for future initiatives and priorities for public drinking water source water protection
(SWP) activities. The PWS Section encourages all PWS system owners to implement efforts to
manage identified sources of contamination and to reduce or eliminate the potential threat to
drinking water supplies through locally implemented programs

To encourage and support local SWP, the state offers PWS system owners assistance with local
SWP as well as materials such as:

ƒ fact sheets outlining sources of funding and other resources for local SWP efforts;
ƒ success stories describing local SWP efforts in North Carolina; and
ƒ guidance about how to incorporate SWAP and SWP information in Consumer Confidence
Reports (CCRs).

Information related to SWP can be found at http://www.deh.enr.state.nc.us/pws/swap.
Chapter 18 – Water Resources 173
18.5.5 Public Water Supply Susceptibility Determinations in the Roanoke River Basin

In April 2004, the PWS Section completed source water assessments for all drinking water
sources and generated reports for the PWS systems using these sources. A second round of
assessments were completed in April 2005. The results of the assessments can be viewed in two
different ways, either through the interactive ArcIMS mapping tool or compiled in a written
report for each PWS system. To access the ArcIMS mapping tool, simply click on the “NC
SWAP Info” icon on the PWS web page (http://www.deh.enr.state.nc.us/pws/swap). To view a report,
select the PWS System of interest by clicking on the “SWAP Reports” icon.

In the Roanoke River Basin, 456 public water supply sources were identified. Thirteen are
surface water sources and 443 are groundwater sources. Of the 443 groundwater sources, 15
have a Higher susceptibility rating, 403 have a Moderate susceptibility rating and 25 have a
Lower susceptibility rating. Table 19 identifies the thirteen surface water sources and the overall
susceptibility rating. It is important to note that a susceptibility rating of Higher does not imply
poor water quality. Susceptibility is an indication of a water supply's potential to become
contaminated by the identified PCSs within the assessment area.

Table 19 - SWAP Results for Surface Water Sources in the Roanoke River Basin

PWS ID Number Inherent Vulnerability Rating
Contaminant Rating Overall Susceptibility Rating
Name of Surface Water Source Public Water Supply Name
0217010 M L M Fullers Creek Town of Yanceyville
0217010 M L M Farmer Lake Town of Yanceyville
0273010 M L M Lake Roxboro City of Roxboro
0273409 M L M Hyco Lake Roxboro Steam Plant
0273427 M L M Mayo Lake CP&L-Mayo Elec Gen Plant
0273010 M L M City Lake City of Roxboro
0279010 H H H Dan River Town of Eden
0279025 H L M Mayo River Town of Mayodan
0279030 H M H Dan River Town of Madison
0291010 M L M Kerr Lake
Henderson-Kerr Lake
Regional Water
0442010 M L M Roanoke Rapids Lake
Roanoke Rapids Sanitary
District
0442010 H L M Roanoke River
Roanoke Rapids Sanitary
District
0442020 H L M Roanoke River Weldon Water System
H – higher; M – moderate; L – lower.

174 Chapter 18 – Water Resources
03010103
03010104
03010102
03010106 03010107
03-02-09
03-02-08
03-02-01
03-02-03 03-02-05 03-02-06
03-02-10
03-02-04
03-02-02
03-02-07
®Planning Section
Basinwide Planning Unit
May 15, 2006
0 2040608010
Miles
Figure 25 8-Digit Hydrologic Units in the Roanoke River Basin
176 Chapter 18 – Water Resources