HomeMy WebLinkAboutChapter 2
Chapter 2
Savannah River Subbasin 03-13-02
Including: Horsepasture, Thompson, and Whitewater Rivers
2.1 Subbasin Overview
The Horsepasture and Toxaway Rivers originate in
Jackson and Transylvania counties and flow in a
southeastern direction toward South Carolina’s Lake
Jocassee. The Horsepasture falls more than 2,000 feet in
the North Carolina portion of the watershed and contains
several spectacular waterfalls. Other tributaries in this
subbasin include the Whitewater and Thompson Rivers.
Most of the land within this subbasin is forested (95.6
percent). The Whitewater River watershed lies within the
Nantahala National Forest. The Gorges State Park and
Toxaway Game Lands encompass 10,000 acres in this
subbasin (mostly the Toxaway River watershed). There
are no municipalities; however, several residential and
resort communities exist near Sapphire and Lake
Toxaway.
Water quality in this subbasin is generally good to
excellent. Nearly all waters are classified trout waters.
Several streams including Bearwallow Creek and a
portion of the Whitewater River are High Quality Waters.
Additionally, 4.5 miles of the Horsepasture River are both
a State Natural and Scenic River and a National Wild and
Scenic River.
Additional information regarding population and land use
throughout the entire basin can be found in Appendix I
and III, respectively.
There are eleven NPDES dischargers in this subbasin, two
of which are required to perform whole effluent toxicity
testing. The Carolina Mountain Water WWTP
(NC0067954, 0.006 MGD) discharges to an unnamed
tributary of the Whitewater River and has had no toxicity
violations since 1997. The other NPDES facility in this
subbasin is the Wade Hampton Club WWTP (NC0062553, MGD 0.125). This facility
discharges to an unnamed tributary to Silver Run Creek and has had no toxicity violations since
1998. For the listing of NPDES permit holders, refer to Appendix V.
Subbasin 03-13-02 at a Glance
Land and Water Area
Total area: 98 mi2
Land area: 96 mi2
Water area: 2 mi2
Population Statistics
2000 Est. Pop.: 7,267 people
Pop. Density: 75 persons/mi2
Land Cover (percent)
Forest/Wetland: 95.6%
Surface Water: 2.1%
Urban: 0.3%
Cultivated Crop: 0.1%
Pasture/
Managed Herbaceous: 1.9%
Counties
Jackson, Transylvania
Municipalities
Cashiers
Monitored Streams Statistics
Aquatic Life
Total Streams: 106.6 mi
Total Supporting: 28.7 mi
Total Impaired: 0 mi
Total Not Rated: 0 mi
Recreation
Total Streams: 3.9 mi
Total Supporting: 3.9 mi
Chapter 2 – Savannah River Subbasin 03-13-02 21
!rpo
!(à
!(à
!(à!(à !(à
!(à
[
[
[[#*
#*
#*
#*
#*
#*
#*
#*
#*
#*Lake
Toxaway HB1
Whitewater
Ri
v
e
r
T
h
omp
s
o
n
River
Toxawa
y
Riv
e
r
Bearwallow Creek
Ho
r
se
pa
sture R
iv
e
r
Fairfield
Lake
TRANSYLVANIA
JACKSON
NC-107
NC-281
US -6 4
Fr
o
z
e
n
C
r
e
e
k
HL6
HL5
HL4
HL3
HB8
HB5
HB4 HB3HB2
HB1
HA1
0 2.5 5 7.5 101.25
Miles
Planning Section
Basinwide Planning Unit
July 18, 2006
Figure 5 Savannah River Subbasin 03-13-02
Legend
NPDES Discharges
#*Major
#*Minor
Monitoring Stations
!(à Benthic Community
Fish Community
po Ambient Monitoring Station
[Lake Monitoring Station
ó Recreation Locations
Aquatic Life Use Support Rating
No Data
Not Rated
Supporting
Impaired
County Boundary
Municipality
Subbasin Boundary
Primary Roads
AU Number
Description
Length/AreaClassification
AL Rating REC RatingStation
Year/
ParameterResult % Exc
Aquatic Life Assessment
ResultStation
Recreation Assessment
Stressors Sources
Savannah 03-13-02SubbasinTable 6
Bearwallow Creek
4-7-(2)
From a point 2.3 miles upstream of mouth to Toxaway River
2.2 FW MilesC Tr HQW S ND
HB5 E 2004
Horsepasture River
4-13-(0.5)b
From dam at Sapphire Lake to NC 281
3.9 FW MilesC Tr S SHA1 NCE
HB2 G 2004
HA1 NCE Fecal Coliform Bacteria Unknown
Fecal Coliform Bacteria WWTP NPDES
Habitat Degradation Unknown
Temperature Unknown
Indian Creek
4-5-(3)
From Dam at Indian Lake Estates Recreation Lake to
Toxaway River
5.4 FW MilesC Tr S ND
HB1 E 2004
Thompson River
4-14-6
From source to North Carolina-South Carolina State Line
5.9 FW MilesC Tr S ND
HB4 E 2004
TOXAWAY RIVER
4-(4)
From Dam at Lake Toxaway Estates, Inc. to North Carolina-
South Carolina State Line
6.2 FW MilesC S ND
HB3 E 2004
TOXAWAY RIVER (Lake Toxaway)
4-(1)
From source to Dam at Lake Toxaway Estates, Inc.
524.9 FW AcresB Tr NR NDHL3 ID
HL4 ID
HL5 ID
HL6 ID
Savannah Subbasin 03-13-02Wednesday, November 22, 2006 2:11:3DRAFT
AU Number
Description
Length/AreaClassification
AL Rating REC RatingStation
Year/
ParameterResult % Exc
Aquatic Life Assessment
ResultStation
Recreation Assessment
Stressors Sources
Savannah 03-13-02SubbasinTable 6
Whitewater River
4-14-(1.5)
From Little Whitewater Creek to North Carolina-South
Carolina State Line
5.2 FW MilesC Tr HQW S ND
HB8 E 2004
Use Categories:Monitoring data type: Use Support Ratings 2006:
AL - Aquatic Life HF - Fish Community Survey E - Excellent S - Supporting, I - Impaired
REC - Recreation HB - Benthic Community Survey G - Good NR - Not Rated
HA - Ambient Monitoring Site GF - Good-Fair NR*- Not Rated for Recreation (screening criteria exceeded)
HL- Lake Monitoring F - Fair ND-No Data Collected to make assessment
P - Poor
NI - Not Impaired
Miles/Acres m- Monitored
FW- Fresh Water e- Evaluated CE-Criteria Exceeded > 10% and more than 10 samples
NCE-No Criteria Exceeded
ID- Insufficeint Data Available
Results
Results:
Aquatic Life Rating Summary
S 28.7 FW Milesm
NR 524.9 FW Acresm
ND 77.9 FW Miles
ND 125.6 FW Acres
Recreation Rating Summary
3.9 FW MilesSm
102.8 FW MilesND
650.5 FW AcresND
Fish Consumption Rating Summary
106.7 FW MilesIe
650.5 FW AcresIe
Savannah Subbasin 03-13-02Wednesday, November 22, 2006 2:11:3DRAFT
A map including the locations of the NPDES facilities and water quality monitoring stations is
presented in Figure 5. Table 6 contains a summary of assessment unit numbers (AU#) and
lengths, streams monitored, monitoring data types, locations and results, along with use support
ratings for waters in the subbasin. Refer to Appendix VIII for more information about use
support ratings.
There were 10 benthic macroinvertebrate community samples collected during this assessment
period. The Whitewater River and the Thompson River maintained Excellent bioclassifications,
Indian Creek improved from Good in 1999 to Excellent in 2004, and the Horsepasture River
declined in bioclassification from Excellent in 1999 to Good in 2004. Data were also collected
from one ambient monitoring station. This ambient station is located on the Horsepasture River
mainstem at NC281. No water quality standards were violated. Refer to the 2005 Basinwide
Assessment Report Savannah River Basin at
http://h2o.enr.state.nc.us/esb/Basinwide/SAV2005.pdf and Appendix IV for more information on
monitoring.
Waters in the following sections and in Table 6 are identified by an assessment unit number
(AU#). This number is used to track defined segments in the water quality assessment database,
list 303(d) Impaired waters, and is used to identify waters throughout the basin plan. The AU# is
a subset of the DWQ index number (classification identification number). A letter attached to
the end of the AU# indicates that the assessment is smaller than the DWQ index segment. No
letter indicates that the AU# and the DWQ index segment are the same. For example, index
number 11-3-(14) might be split into two assessment units 11-3-(14)a and 11-3-(14)b.
2.2 Use Support Assessment Summary
All surface waters in the state are assigned a
classification appropriate to the best-intended use of
that water. Waters are regularly assessed by DWQ
to determine how well they are meeting their best-
intended use. For aquatic life, an Excellent, Good,
Good-Fair, Fair, or Poor bioclassification is
assigned to a stream based on the biological data
collected by DWQ. For more information about
bioclassification and use support assessment, refer
to Appendices IV and VIII, respectively. Appendix
IX provides definitions of the terms used
throughout this basin plan.
In subbasin 03-13-02, use support was assigned for
the aquatic life, recreation, fish consumption and
water supply categories. (Table 7) Waters are
Supporting, Impaired, Not Rated, and No Data in
the aquatic life and recreation categories on a
monitored or evaluated basis. Waters are Impaired
in the fish consumption category on an evaluated basis based on fish consumption advice issued
by the Department of Health and Human Services (DHHS). All waters are Supporting in the
water supply category on an evaluated basis based on reports from Division of Environmental
Table 7 Summary of Use Support
Ratings by Category in Subbasin 03-13-02
Use Support
Rating Aquatic Life Recreation
Monitored Waters
Supporting 28.7 mi 3.9 mi
Impaired* 0 0
Not Rated 524.9 ac 0
Total 28.7 mi
524.9 ac
3.9 mi
Unmonitored Waters
No Data 77.9 mi
125.6 ac
102.8 mi
650.5 ac
Total 77.9 mi
125.6 ac
102.8 mi
650.5 ac
Totals
All Waters** 106.6 mi
650.5 ac
106.7 mi
650.5 ac
* The noted percent Impaired is the percent of monitored
miles/acres only.
** The noted percent Impaired is the percent of monitored
miles/acres only.
DRAFT Chapter 2 – Savannah River Subbasin 03-13-02 25
Health (DEH) regional water treatment plant consultants. Refer to Table 7 for a summary of use
support for waters in subbasin 03-13-02.
2.3 Status and Recommendations of Previously and Newly Impaired
Waters
No stream segments were rated impaired in the 2002 basin plan and none were rated as impaired
based on recent DWQ monitoring in the current assessment period (1999-2004). Section 2.4
below discusses specific streams where water quality impacts have been observed.
2.4 Status and Recommendations for Waters with Noted Impacts
The surface waters discussed in this section are not Impaired. However, notable water quality
problems and concerns were documented for these waters during this assessment. Attention and
resources should be focused on these waters to prevent additional degradation and facilitate
water quality improvements. DWQ will notify local agencies of these water quality concerns
and work with them to conduct further assessments and to locate sources of water quality
protection funding. Additionally, education on local water quality issues and voluntary actions
are useful tools to prevent water quality problems and to promote restoration efforts. The current
status and recommendations for addressing these waters are presented below, and each is
identified by an AU#. Nonpoint source program agency contacts are listed in Appendix VII.
2.4.1 Horsepasture River [AU# 4-13-(.5)b] and Headwaters
Including: Hog Back and Little Hogback Creeks, Hogback Lake [AU# 4-13-9 and
4-13-8]
Current Status
DWQ samples the Horsepasture River’s benthic community at site HB2. Between 1999 and
2004 this location declined from Excellent to Good. However, it should be noted that the
bioclassification at this site has varied since DWQ first sampled here in 1985 (Table 8). DWQ
also maintains an ambient monitoring station at this location. Ambient data indicate that
physical water quality did not change significantly at this site between 1999 and 2004 and
suggests the recent variability in bioclassification may be natural. The ambient data also
revealed fecal coliform bacteria concentrations are trending upwards, but do not yet violate state
standards. This could be due to the increased presence of septic systems in the watershed and/or
intense recreational use. The Horsepasture River is a popular swimming destination in the
summer. Sapphire Lakes WWTP #1 has also had difficulty meeting its fecal coliform permit
limit. DWQ is pursuing enforcement actions to correct the problem.
Concerned citizens provided DWQ with photographic evidence of instream habitat degradation
in many tributaries of the Horsepasture River, especially the Hog Back Creek watershed. The
photographs document the impact of development in the watershed and include: removal of
riparian vegetation resulting in bank collapse, erosion near stormwater collection system outfalls,
un-stabilized road cuts, heavy siltation in small streams, and failing erosion control structures.
26 DRAFT Chapter 2 – Savannah River Subbasin 03-13-02
Table 8 Bioclassifications for the Horsepasture River at NC281
Year Bioclassification
1984 Good-Fair
1985 Fair
1986 Good
1987 Good
1989 Good-Fair
1994 Good
1999 Excellent
2004 Good
The average ambient water temperature appears to be rising at site HA1. This was determined
by fitting a linear regression trend line for temperature data from 1985 through 1996. Because
there is no flow information to accompany this data, DWQ could not perform a season-and-flow
adjusted trend analysis, and these results should be considered preliminary. Some possible
causes for a long-term temperature increase include a large-scale climatic shift or direct human
induced changes such as increased impervious cover or riparian vegetation removal coupled with
impacts from small ponds. Despite some new development, impervious surfaces remain a
relatively small percentage (<2 percent) of the landscape in the Horsepasture River watershed
(Figure 6). Therefore, the most likely causes of increasing water temperature include riparian
vegetation removal, small ponds, and climate change. Changes due to riparian vegetation
removal are relatively easy and inexpensive to correct by replanting the riparian zone with shade
trees.
Figure 6 Ambient Water Temperature in the Horsepasture River
0
5
10
15
20
25
30
Jan-85 Jan
-86
Jan-87
Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-9
3
Jan-94
Jan-95 Jan-96
De
g
r
e
e
s
C
e
l
s
i
u
s
Water Temperature
Trend - Linear Regression
DRAFT Chapter 2 – Savannah River Subbasin 03-13-02 27
The NC Ecosystem Enhancement Program (NCEEP) has initiated an approximately 8,000-foot
stream mitigation project on Logan Creek, a tributary to the Horsepasture River near the town of
Cashiers in Jackson County. The project is currently in the early design phase, with construction
expected to begin by the summer of 2007. For additional information about NCEEP watershed
initiatives, see Section 11.3.1.
DWQ received a request to reclassify the Horsepasture River to Outstanding Resource Waters in
2006. In the summer of 2006, DWQ conducted biological studies of the river and its major
tributaries to determine if they would qualify for ORW classification. A great deal of the study
was conducted in rapidly developing areas. Active land clearing activities at several sites will
likely affect the riparian zone's effectiveness at controlling pollutant loading including
sedimentation. In at least one instance, sediment control measures apparently put in place
immediately adjacent to the stream to slow these problems were circumvented. With the
Horsepasture River itself starting out near, and flowing through a relatively low-gradient area
from the confluence of Logan Creek to the confluence of Rock Creek, this area, including many
of the tributaries may be very sensitive to sedimentation and sediment-borne pollutants.
Additional controls on, or better regulation of non-point source pollutants may be needed to
protect the current status of these resources and to maintain the excellent water quality observed
in the lower portion of the Horsepasture River.
2007 Recommendations
Nonpoint source pollution presents the greatest threat to water quality in the Horsepasture River.
In order to protect water quality, development along the river and its many tributaries must be
conducted in an ecologically sound manner including an emphasis on managing stormwater
runoff. Refer to Chapter 5 for information on how local governments can achieve effective
stormwater control on existing and future development.
In addition to local government action, residents should take an active role in water quality
management. Citizens are encouraged to report erosion problems and possible water quality
violations to state and county authorities. They should also work through their homeowner
associations to encourage and establish appropriate stormwater controls in their communities.
Citizens can also track changes in water quality by starting a volunteer monitoring program to
supplement state water quality data. Interested citizens should contact the VWIN program at the
University of Asheville for guidance on how to start such a program. Residential landowners
along the creek can use a variety of techniques to reduce pollution caused by runoff from their
property. Residents should refer to the document “Improving Water Quality in Your Own
Backyard.” This pamphlet is available free of charge through the Division of Water Quality
Website http://h2o.enr.state.nc.us/nps/documents/BackyardPDF.pdf.
2.4.2 Toxaway River (Lake Toxaway) [AU# 4-(1) & 4-(4)]
Current Status
Bottom water in Lake Toxaway was sampled in conjunction with a study being conducted by the
Division of Water Resources (DWR) in response to odor complaints below the dam. In 2001,
2002, and 2003, the DWR received complaints regarding the odor of bottom water released into
the Toxaway River from Lake Toxaway. Bottom water is released from the reservoir in an
attempt to provide colder water in the Toxaway River downstream of the dam to support a trout
fishery. In response to the public complaints, a study of the river downstream of the Lake
Toxaway Dam was conducted by DWR to determine the source of the odor problem. In support
28 DRAFT Chapter 2 – Savannah River Subbasin 03-13-02
of this investigation, DWQ sampled the bottom water of Lake Toxaway near the dam to evaluate
the levels of metals, particularly manganese, an element associated with taste and odor problems
in drinking water. Results of this sampling indicate that both manganese and iron increased
significantly in response to increased hypoxic conditions near the bottom of the lake as the
summer progressed. At these elevated concentrations, staining, odor, and unpleasant taste are
noticeable. Lake Toxaway is Not Rated in the aquatic life use support category because DWQ
did not collect the minimum ten samples necessary to assign a use support rating.
DWQ also sampled the benthic community in the Toxaway River about five miles below the
dam. At this point (Site HB3), the benthic community was rated Excellent, indicating either the
dam did not have a significant impact, or the impact attenuated relatively quickly after release.
The river is rated Supporting for aquatic life from the dam at Lake Toxaway to the state line.
2007 Recommendations
The Toxaway River below the lake is now protected within Gorges State Park. Therefore, the
most likely threats to water quality will manifest in the lake and headwaters. In order to protect
water quality in this area, development must proceed in an ecologically sound manner. Refer to
Chapter 5 for recommendations on how growth and development can be managed effectively.
2.5 Additional Water Quality Issues within Subbasin 03-13-02
The previous sections discussed water quality concerns for specific stream segments. The
following section discusses issues that may threaten water quality in the subbasin that are not
specific to particular streams, lakes, or reservoirs. The issues discussed may be related to waters
near certain land use activities or within proximity to different pollution sources.
This section also discusses ideas, rules, and practices in place to preserve and maintain the
pristine waters of the Savannah basin. In subbasins 03-13-01 (Chapter 1) and 03-13-02, this is
particularly important since many of the waters are designated high quality or outstanding
resource waters (HQW and ORW, respectively).
2.5.1 Management Strategies for Water Quality Protection
Municipalities and smaller outlying communities are expanding. This involves construction and
development along pristine waters in Subbasin 03-13-02. HQW and ORW are supplemental
classifications to the primary freshwater classification(s) placed on a waterbody (Chapter 3).
Management strategies are associated with the supplemental HQW and ORW classifications and
are intended to protect the current use of the waterbody. A summary of the special management
strategies for HQW and ORW waters can be found in Chapter 1. Detailed information can be
found in the document entitled Classifications and Water Quality Standards Applicable to
Surface Waters and Wetlands of North Carolina (NCDENR-DWQ, 2004). This document is
available on-line at http://h2o.enr.state.nc.us/admin/rules/.
Many of the streams in this subbasin are also classified as trout (Tr) waters, and therefore, are
protected for natural trout propagation and maintenance of stocked trout. There are no watershed
development restrictions associated with the trout classification; however, the NC Division of
Land Resources (DLR), under the NC Sedimentation and Pollution Control Act (SPCA), has
requirements to protect trout streams from land disturbing activities. Under G.S. 113A-57(1),
“waters that have been classified as trout waters by the Environmental Management Commission
DRAFT Chapter 2 – Savannah River Subbasin 03-13-02 29
(EMC) shall have an undisturbed buffer zone 25 feet wide or of sufficient width to confine
visible siltation within the twenty-five percent of the buffer zone nearest the land-disturbing
activity, whichever is greater.” The Sedimentation Control Commission, however, can approve
land-disturbing activities along trout waters when the duration of the disturbance is temporary
and the extent of the disturbance is minimal. This rule applies to unnamed tributaries flowing to
the affected trout water stream. Further clarification on classifications of unnamed tributaries
can be found under Administration Code 15A NCAC 02B .0301(i)(1). For more information
regarding land-disturbing activities along designated trout streams, see the DLR website at
http://www.dlr.enr.state.nc.us/.
2.5.2 Septic System Concerns
Development of rural land in areas not served by sewer systems is occurring rapidly in the
Savannah River basin. Hundreds of permit applications for onsite septic systems are approved
every year. Septic systems generally provide a safe and reliable method of disposing of
residential wastewater when they are sited (positioned on a lot), installed, operated, and
maintained properly. Rules and guidelines are in place in North Carolina to protect human
health and the environment. Water quality is protected by locating the systems at least 50 feet
away from streams and wetlands, limiting buildable lot sizes to a ¾-acre minimum, and
installing drain fields in areas that contain suitable soil type and depth for adequate filtration;
drinking water wells are further protected by septic system setbacks.
Septic systems typically are very efficient at removing many pollutants found in wastewater
including suspended solids, metals, bacteria, phosphorus, and some viruses. However, they are
not designed to handle other pollutants that they often receive such as solvents, automotive and
lubricating oil, drain cleaners, and many other household chemicals. Additionally, some
byproducts of organic decomposition are not treated. Nitrates are one such byproduct and are the
most widespread contaminant of groundwater in the United States (Smith, et al., 2004).
One septic system generates about 30 to 40 pounds of nitrate nitrogen per year (NJDEP, 2002).
Nitrates and many household chemicals are easily dissolved in water and therefore move through
the soil too rapidly to be removed. Nitrates are known to cause water quality problems and can
also be harmful to human health (Smith, et al., 2004).
Proper location, design, construction, operation, and maintenance of septic systems are critical to
the protection of water quality in a watershed. If septic systems are located in unsuitable areas,
are improperly installed, or if the systems have not been operated and/or maintained properly,
they can be significant sources of pollution. Additionally if building lots and their corresponding
septic systems are too densely developed, the natural ability of soils to receive and purify
wastewater before it reaches groundwater or adjacent surface water can be exceeded (Smith, et
al., 2004). Nutrients and some other types of pollution are often very slow to leave a lake
system. Therefore, malfunctioning septic systems can have a significant long-term impact on
water quality and ecological health (PACD, 2003).
Local governments, in coordination with local health departments, should evaluate the potential
for water quality problems associated with the number and density of septic systems being
installed throughout their jurisdiction. Long-term county-wide planning for future wastewater
treatment should be undertaken. There are water quality concerns associated with both
continued permitting of septic systems for development in outlying areas and with extending
30 DRAFT Chapter 2 – Savannah River Subbasin 03-13-02
sewer lines and expanding wastewater treatment plant discharges. Pros and cons of various
wastewater treatment options should be weighed for different parts of the county (based on soil
type, depth, proximity to existing sewer lines, etc.) and a plan developed that minimizes the risk
of water quality degradation from all methods employed.
In addition, local governments, again in coordination with local health departments, should
consider programs to periodically inform citizens about the proper operation of septic systems
and the need for routine maintenance and replacement. Owners of systems within 100 feet of
streams or lakes should be specifically targeted and encouraged to routinely check for the
warning signs of improperly functioning systems and to contact the health department
immediately for assistance in getting problems corrected.
2.5.3 Wooly Adelgid Pesticide Use
Citizens in the Savannah River basin informed DWQ of widespread, improper pesticide use by
untrained persons attempting to control the spread of wooly adelgid infestations in eastern
hemlock stands. The eastern hemlock is common along streams in the southern Appalachians.
When used improperly or excessively, pesticides intended for use on trees can runoff into nearby
streams causing catastrophic declines in aquatic communities. The NC Division of Forrest
Resources can advise concerned citizens on the proper techniques for wooly adelgid control.
http://www.dfr.state.nc.us/
DRAFT Chapter 2 – Savannah River Subbasin 03-13-02 31
32 DRAFT Chapter 2 – Savannah River Subbasin 03-13-02