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Section 319
NONPOINT SOURCE PROGRAM SOCCESS STORY
Conservation Practices Result in Improved Bacteria Levels in Walnut Creek
Waterbodv Improved Walnut Creek was imPaired t&Escheffctoa con (E. coin
'"' bacteria and was added to Oklahoma's Clean Water Act
(CWA) section 303(d) list of impaired waters in 2006. Due in part to practices associated
with cattle and hog production, the impairment was addressed through implementation
of a system of conservation practices (CPs) that focused on improving grazingland and
excluding livestock from riparian areas. This effort led to a sustained decrease in bacteria
in the creek, resulting in removal of Walnut Creek for E. coli impairment from Oklahoma's
CWA section 303(d) list in 2014.
Problem
Twenty-eight-mile-long Walnut Creek
(OK520610030010 _ 00) flows through McClain
County in central Oklahoma (Figure 1). The majority
of the land in the 129,852-acre watershed is used
for wheat and cattle production. Many hogs are also
produced, in addition to corn, sorghum and soybeans.
Erosion of both cropland and grazingland, coupled
with improper management of livestock wastes and
direct livestock access to streams, were potentially
the largest nonpoint source (NPS) problems in the
watershed, contributing to high levels of fecal bacteria
in the stream. In the 2006 water quality assessment,
£ coli bacteria levels exceeded the state crite-
rion, with a geometric mean of 179 colony forming
units/100 milliliters (CPU). The primary body contact
recreation designated use is considered impaired if
the geometric mean exceeds 126 CPU for£ coli.
Project Highlights
Landowners implemented numerous CPs with sup-
port from Oklahoma Conservation Commission's
(OCC's) Locally Led Cost Share (LLCS) program and
funds from the U.S. Department of Agriculture's
Natural Resources Conservation Service (NRCS)
general technical assistance programs and the
Pnvironmental Quality Incentives Program. The focus
of most CPs in this watershed was proper grazing
management, including fencing livestock out of
streams, and improved pasture and rangeland qual-
ity, as runoff from poor quality land can carry both
sediment and fecal bacteria into waterbodies.
From 2009 to 2012, landowners installed
30,619 linear feet of fence and implemented
Walnut Creek Watershed
Figure 1. The Walnut Creek watershed flows through McClain
County in central Oklahoma.
10,837 acres of prescribed grazing. Sixteen new
ponds provided alternative water supplies for
livestock after cross-fencing to optimize grazing-
land usage. Landowners also cooperated in nutri-
ent management planning on nearly 9,000 acres.
Brush management on more than 1,200 acres
helped improve pasture and range quality, as did
1,500 acres of supplemental biomass and critical
area planting and 7,330 acres of pest management.
Cover crops increased the soil health of more than
1,800 acres of pasture and range, and no-till or
reduced till methods were used in these areas.
To reduce erosion from sloped areas, producers
installed grassed waterways, terraces, diversions
and grade stabilization structures. Upland wildlife
habitat management practices were implemented
on 149 acres, and stream habitat improvement and
management CPs were conducted over 89 acres.
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Bacteria Data, Walnut Creek
3000-
2500-
3 2000-
LI-
ES
8 1500'
ULJ
1000"
500"
0"
*
Geometr
mean= 1
|
2006
Geometr c
mean = 271
c
79
Geometric
mean = 168
Geometric
mean =46
2008 2010
Assessment Year
2014
Figure 2. Boxplots indicate the interquartile range
(25th-75th percentile) and median of the data for
assessment years 2006, 2008, 2010 and 2014. A
stream meets criteria for £ coli if the geometric
mean, based on no more than five years of data
preceding the assessment year, is less than 126
colony forming units/100 ml (CPU).
Oklahoma's NPS education program, Blue Thumb,
held several volunteer monitoring trainings in the
area. A local high school teacher and her students
monitored Walnut Creek for a year, and another
group of citizens collected water quality, benthic
macroinvertebrates and fish data for two years.
Landowners installed additional CPs from 2013
through 2014 that have enhanced the initial improve-
ments. CPs included prescribed grazing manage-
ment (4,570 acres), nutrient management (159 acres),
grazing management (4,122 acres), supplemental
vegetation planting (285 acres) and fencing practices
(3,700 linear feet).
Results
The OCC's statewide NPS ambient monitoring pro-
gram documented improved water quality in Walnut
Creek due to conservation efforts (Figures 2 and 3).
The installed grazingland and nutrient management
CPs worked to decrease erosion and reduce bacteria
loading. CPs designed to improve pasture and range-
land resulted in denser vegetation and fewer bare
spots, which reduced runoff of soil, nutrients and
bacteria from animal wastes into waterbodies. In the
2014 assessment, monitoring data showed that the
geometric mean of E. coli had decreased to 46 CFU,
which is significantly below the state standard of
Figure 3The OCC Rotating Basin Monitoring Program
documented improved water quality in Commission
Creek, seen here in 2015.
126 CFU. Hence, Walnut Creek was removed for£
coli impairment from the 2014 CWA section 303(d)
list and is in partial attainment of the primary body
contact recreation use. With continued good man-
agement, the waterbody is expected to fully attain its
primary recreation designated use.
Partners and Funding
The improvement in water quality in Walnut Creek
was documented by OCC's statewide NPS ambi-
ent monitoring effort known as the Rotating Basin
Monitoring Program (RBMP). The RBMP is funded
in part with U.S. Environmental Protection Agency
(EPA) CWA section 319 funds at a total annual cost
of $1 million. This funding supports personnel,
supplies, lab analyses and other associated costs.
Sampling efforts comprise 20 water quality collec-
tions at approximately 100 sites every five weeks
per five-year cycle. Instream habitat, fish and macro-
invertebrate samples are also collected during this
period. Statewide educational efforts through OCC's
Blue Thumb Program are also funded by EPA section
319 at a cost of approximately $600,000 annually.
These funds support costs associated with volunteer
monitoring at nearly 100 sites, volunteer trainings and
many outreach activities. The OCC LLCS program pro-
vided $60,000 in state funding for CP implementation
in this watershed through the McClain Conservation
District with landowners contributing $43,148 in
match. The NRCS spent a little over $1 million through
its financial assistance programs for CP implementa-
tion in McClain County from 2009 through 2012 (pre-
delisting period). Implementation is still ongoing, with
NRCS spending an additional $500,000 since 2013.
I
3
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-15-001JJ
August 2015
For additional information contact:
Shanon Phillips
Oklahoma Conservation Commission
shanon.phillips@conservation.ok.gov
405-522-4500
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