Section 319
NONPOINT SOURCE PROGRAM SOCGESS STORY
Implementing Urban Best Management Practices Improves Water Quality
WatPrhndiPS Imnrnvpd P°"u1:ec' runoff from increased development in western
North Carolina had degraded water quality in the
Swannanoa River watershed. As a result, the North Carolina Division of Water Quality (NC
DWQ) placed two Swannanoa River segments (totaling 14 miles) on the Clean Water Act
(CWA) section 303(d) list of impaired waters in 2006 and 2008. Both segments were listed
for impaired biological integrity attributed to urban development, and one segment was also
listed for turbidity. Implementing best management practices (BMPs) led to improved water
quality, prompting NC DWQ to remove the two segments of the Swannanoa River from the
CWA section 303(d) list of impaired waters in 2008 and 2010.
Problem
The Swannanoa River watershed drains a mountain-
ous region of western North Carolina within the
French Broad River Basin. Residential and com-
mercial development contributed high volumes
of sediment-laden runoff, which degraded the
Swannanoa River watershed (Figure 1). Water qual-
ity issues were identified in the Swannanoa River
beginning in 1998. The NC DWQ added segments
6-78c (2.6 miles long) and 6-78d (11.5 miles long) of
the Swannanoa River to the CWA section 303(d) list
of impaired waters in 2006 and 2008. The two river
segments run through the town of Black Mountain,
just outside the city of Asheville in Buncombe
County. Both segments were listed because of
impaired biological integrity linked to urban develop-
ment; segment 6-78d was also listed as impaired by
turbidity.
The 2005 French Broad Basin Plan identified habitat
degradation, poor-quality riparian buffer zones, nutri-
ent enrichment, sedimentation, channelization and
toxicity as water quality problems in the Swannanoa
River watershed. To address the problems, the
2005 Plan recommended increasing water quality
monitoring, local ordinance development and natural
resource protection throughout the watershed.
Project Highlights
RiverLink, a regional nonprofit organization dedicat-
ed to revitalizing the French Broad River watershed,
received CWA section 319 project funds from the
NC DWQ in 2000. Its project goals were to imple-
ment BMPs in the Swannanoa River watershed that
Figure 1. Project partners restored streambanks
along a developed portion of Haw Creek, a tributary
of the Swannanoa River.
would restore the river's biological integrity and
serve as education and outreach tools for citizens
and businesses in the Black Mountain community.
With section 319 funding, RiverLink created a
technical staff position for outreach to landown-
ers, elected and appointed officials, and planning
and stormwater management staff. The group built
community partnerships with the goal of developing
local ordinances to prevent nonpoint source pollu-
tion in the entire Swannanoa River watershed.
RiverLink worked with members of the watershed
community to implement various BMPs (Table 1).
For example, landowners established two conserva-
tion easements that provided extended protection
of the river—a 150-linear-foot buffer on both sides
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of a 1.3-mile segment of the river and an ease-
ment on a 7-acre natural wetland. Along the same
1.3-mile segment, partners restored and stabilized
the streambanks and replanted the riparian area.
In other areas of the watershed, partners restored
streambanks and installed structural BMPs
designed to capture and treat stormwater runoff,
including rain gardens, bioswales and stormwater
wetlands (Figures 2 and 3). Those combined efforts
have all contributed to improved water quality in the
Swannanoa.
Table 1. Swannanoa River Project BMPs
Results
BMP Installed
Riparian
Plantings
Invasive Exotic
Plant Removal
Streambank
Restoration
Conservation
Easements
Bioretention
Cells
Rain Gardens
Location
Haw Creek,
Swannanoa
River
Haw Creek
Haw Creek,
Swannanoa
River
Azalea Park
Black
Mountain
Haw Creek,
Black
Mountain
Total Number Completed
2 projects
3 projects
4 projects
300-foot buffer along
1.3 stream miles
(—25 acres) and a
7-acre wetland
2 projects
3 projects
Area/Size
8,814 feet
1,950 feet
8,814 feet
32 acres
< 0.5 acres
< 0.3 acres
Figure 2. A rain garden
collects and treats
residential runoff in Black
Mountain.
Figure 3. A
rain garden
at Evergreen
Community
Charter School
captures parking
lot runoff.
The Swannanoa River BMP implementation project
exceeded its intended goals. Partners estimate
that the restoration efforts have reduced the annual
sediment load to the river by more than 500 tons. In
2000 and 2005, NC DWQ Environmental Sciences
Section staff members performed biological
monitoring on the Swannanoa River, using estab-
lished protocols to collect and assess multiple grab
samples and kick net samples. They determined the
EPT (short for the orders Ephemeroptera, Plecoptera
and Trichoptera) taxa richness index, which is a mea-
sure of pollution-sensitive aquatic insects inhabiting
a waterbody. A stream showing high EPT richness is
less likely to be polluted than one with low richness
in the same geographic region.
Data show that the macroinvertebrate rating on a
small 2.6-mile segment (6-78c) of the Swannanoa
River from Beetree Creek to Bull Creek improved
from "fair" (in 1987) to "good-fair" (in 2007), which
meets the biological integrity standard. As a result,
NC DWQ removed the segment from the CWA sec-
tion 303(d) list in 2008.
In addition, data show that the macroinvertebrate
rating on an 11.5-mile segment (6-78d) of the
Swannanoa River from Bull Creek to the French
Broad River improved from "poor" (in 1988) to "good-
fair" (in 2007), which meets the biological integrity
standard. Segment 6-78d also no longer violates the
state's turbidity standard of 50 nephelometric turbid-
ity units. NC DWQ therefore removed the segment
from the CWA section 303(d) list in 2010.
Partners and Funding
A total of $547,563 in CWA section 319 grant
funds supported this project. The City of Asheville,
Town of Black Mountain, Warren Wilson College,
Biltmore Estate, Buncombe County Government,
Land of Sky, Evergreen Community Charter School,
Buncombe County Soil and Water Conservation
District, Montreat College, the Mountain Valley
Resource Conservation and Development pro-
gram, NC DENR DWQ (Asheville), Quality Forward,
Rindt-McDuff Associates, Trout Unlimited-Land of
Sky Chapter, University of North Carolina-Asheville
Environmental Quality Institute, Buncombe County
Metropolitan Sewerage District, Pigeon River Fund,
North Carolina Clean Water ManagementTrust
Fund, and Resource Data, Inc., provided an addi-
tional $365,043 in matching funds.
I
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-11-001Z
April 2011
For additional information contact:
Nancy Hodges
RiverLink
828-252-8474 • Nancy@riverlink.org
Heather Jennings
NC Division of Water Quality
919-807-6437 • Heather.B.Jennings@ncdenr.gov
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