/©% Section 319
K.*ZJ honpiint source prigum success story
PRO^
Tennessee
Implementing Grazing and Erosion Control Best Management Practices
Improves McKnight Branch
M/aterbodv ImDroved Pasture 9razin9 alon9 Tennessee's McKnight Branch contributed
to damaged riparian areas, increased stream siltation, and
habitat alteration, prompting the Tennessee Department of Environment and Conservation
(TDEC) to add the stream to the state's Clean Water Act (CWA) section 303(d) list of impaired
waters in 2000. Project partners implemented agricultural best management practices (BMPs)
that reduced siltation and improved water quality. As a result, TDEC removed McKnight Branch
from the state's CWA section 303(d) list of impaired waters in 2010.
Problem
McKnight Branch is an 18.8-mile-long stream that
flows across rural Cannon and Rutherford counties
in central Tennessee, just east of Murfreesboro.
McKnight Branch is in the McKnight Branch-East
Fork Stones River watershed (HIJC 051302030104),
and it is a part of the larger Stones River watershed
and the Inner Nashville Basin (Figure 1).
Streams in this ecoregion are typically low-gradient
and flow over limestone (Figure 2). The primary land
use in the watershed is farmland. McKnight Branch's
designated uses are livestock watering and wildlife,
irrigation, fish and aquatic life, and recreation.
Monitoring data in 2000 indicated that McKnight
Branch had failed two biological reconnaissance
(biorecon) studies, one in the spring and one in the fall.
Biorecon is a tool used to recognize stream impair-
ment as determined by species richness measures,
emphasizing the presence or absence of indicator
organisms without regard to relative abundance. Low
dissolved oxygen was also observed at one of the
monitoring sites. These data showed that the water-
body failed to support its fish and aquatic life designat-
ed use Therefore, in 2000 TDEC placed the 18.8-mile
McKnight Branch segment (TN05130203026-0200) on
the state's CWA section 303(d) list of impaired waters
for riparian loss and habitat alterations due to pasture
grazing activities. This impaired segment included
Northcutt Branch, a tributary that runs into McKnight
Branch from the east. In 2002 TDEC developed a
siltation and habitat alteration total maximum daily
Figure 1. Landowners implemented numerous BMPs at
priority sites in the McKnight Branch watershed.
load (TMDL) for the Stones River watershed, which
includes McKnight Branch.
Project Highlights
Soil Conservation District (SCD) offices in Cannon
and Rutherford counties helped local landowners
enhance wildlife habitat and implement BMPs to
Cannon County

2 Miles
Note: 1 dot might represent more than 1 BMP
McKnight Branch in the East Fork
Stones River-McKnight Branch Watershed
051302030104 (HUC12) with

McKnight Branch
Watershed
/" Best Management Practices (BMPs)
Porterfield
BMP
Practice
Size

1
Fencing for Rotational Grazing System
3721 feet
2
Heavy Use Area
1HUA
2
Pipeline
1560feet
2
Watering Facility
1 waterer
3
Heavy Use Area
3 HUAs
3
Pipeline
2300feet
3
Watering Facility
2 troughs

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Hgure 2. I his Cannon County stream is typical of
those found in this ecoregion.
improve water quality (Table 1). The SCDs organized
hands-on field days to help farmers understand the
harmful effects of sediment loss and to encourage
them to implement BMPs.
With the encouragement of the SCDs, many farm-
ers installed livestock exclusion fencing to prevent
erosion by keeping animals away from sensitive
streambank areas. They also installed fencing for
rotational grazing, which allowed pasture vegetation
to recover and begin providing greater yields. To
deliver readily available clean water to their animals
in rotational grazing areas, the farmers installed
water distribution systems that included pipelines,
heavy-use areas, and watering facilities (Figure 3).
Table 1. BMPs installed along McKnight
Branch (2006-2007)
NRCS Code
Practice
Size of Practice
382D
Fencing for Rotational
Grazing System
3,721 feet
516
Pipeline
3,860 feet
561
Heavy-Use Area
4 units
614
Watering Facilities
3 units
Results
BMPs implemented along McKnight Branch (see
E gure 1 for BMP locations) are helping to control
erosion and reduce siltation, which in turn has
allowed the waterbody to meet water quality
standards. In 2007, following BMP implementation,
TDEC staff performed a biorecon study at River
Mile 3,0 (upstream of Trimble Road in Porterfield).
The principal metrics used for the survey are (1) the
number of families (or genera) of mayflies, stone-
Hgure 3. Farmers offer alternative water sources for
their animals in rotational grazing areas.
flies, and caddisflies (collectively referred to as
EPT-—short for the order names Ephemeroptera,
Plecoptera, and Trichoptera); (2) the number of
other pollution-intolerant families (or genera); and
(3) the total number of macroinvertebrate families
(or genera) in a stream. The biorecon survey is
scored on a scale from 1 to 15—a score of less
than 5 is regarded as very poor, while a score of
more than 10 is considered good.
The 2007 survey documented 8 EPT families,
5 pollution-intolerant families, and 25 total families,
which translated into a perfect biorecon score of
15 out of 15 and a habitat score of 130 out of 200
(considered good in this ecoregion). These data
indicated significant improvements in the biology
of the stream. McKnight Branch now fully supports
its designated uses, including the fish and aquatic
life use. On the basis of these data, TDEC removed
McKnight Branch from Tennessee's list of impaired
waters in 2010.
Partners and Funding
Many federal and state agencies, local organiza-
tions, and individual landowners worked together
to improve water quality in the McKnight Branch
watershed. Key partners included the SCD offices
of Cannon and Rutherford counties, the U.S.
Department of Agriculture's Natural Resources
Conservation Service (NRCS), the Tennessee
Department of Agriculture's Nonpoint Source
Program, TDEC, and local farmers. BMP installation
was supported by the state's Agricultural Resources
Conservation Fund (created through Tennessee's
real estate transfer tax), NRCS Farm Bill funding,
and matching funds from landowners.
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U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA 841-F-14-Q01K
April 2014
For additional information contact:
Sam Marshall
Tennessee Department of Agriculture
615-837-5306
Sam.Marshall@tn.gov

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