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Implementing Agricultural Conservation Practices Improves Furbidity
Levels in Otter Creek (Tillman County)
Waterbody Improved
Elevated turbidity levels resulted in the impairment of Otter Creek
and placement on Oklahoma's Clean Water Act (CWA) section
303(d) list of impaired waters in 2008. Poor grazing, hay production and cropland management
contributed to this impairment. Implementation of conservation practice systems (CPs) to promote
better quality grazing and crop land management decreased turbidity in the creek. As a result, Otter
Creek was removed from Oklahoma's 2012 CWA 303(d) list for turbidity impairment. Otter Creek
now fuily supports its warm water aquatic beneficial use.
Problem
Otter Creek is a 23.1-mile stream that flows through
Kiowa and Tillman counties before discharging to
Oklahoma's Cimarron River (Figure 1). Land use in the
43,000-acre watershed is primarily cropland (66 per-
cent of total) for wheat production. About 20 percent
of the watershed is pasture for cattle and hay produc-
tion and approximately 7 percent is forested.
Poor management of crop and grazing lands contrib-
uted to excess turbidity In Otter Creek. The stream
was listed as impaired for turbidity in 2008 when
21 percent of baseflow turbidity samples violated
standards. A stream violates the turbidity standard
when more than 10 percent of baseflow samples are
higher than 50 nephelometric turbidity units (NTU).
On the basis of these assessment results, Oklahoma
added Otter Creek (OK311500010080_00) to the 2008
CWA section 303(d) list for nonattainment of the warm
water aquatic beneficial use.
Otter Creek Watershed
Project Highlights
Landowners in the watershed worked with the Kiowa
and Tillman county conservation districts, the U.S.
Department of Agriculture (USDA) Natural Resources
Conservation Service (NRCS), the USDA Farm Services
Agency (FSA) and the Oklahoma Conservation
Commission (OCC) to implement CPs through
Oklahoma NRCS's Environmental Quality Incentives
Program (EQIP), Wildlife Habitat Incentives Program
(WHIP), Conservation Stewardship Program (CSP),
Wetland Restoration Program (WRP) and general
conservation technical assistance program; FSA's
Figure 1. Otter Creek is in southwestern Oklahoma.
Conservation Reserve Program (CRP); and the OCC's
Locally Led Cost-Share Program (LLCP). From 2006 to
2010, landowners implemented pasture and grassland
CPs, including 817 acres of prescribed grazing, 7 acres
of critical area planting, one diversion, five ponds,
three wells, two pumping plants, 103 acres of forage
and biomass planting, 94 acres of nutrient manage-
ment, 1,363 acres of brush management, 71 acres of
prescribed burning and 7,900 feet of firebreak.
Landowners implemented multiple cropland CPs,
including 35 acres of conservation crop rotation, 1,692
acres of reduced tillage residue and tillage manage-

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Otter Creek, Turbidity
25%	21%	0%	4%
exceedance exceedance	exceedance	exceedance
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2006 2008	2012	2016
Figure 2. Monitoring data indicate that turbidity levels
in Otter Creek have declined and now meet standards.
cover crops, 461 acres of access control, one diversion,
138 acres of ridge-till and 996 acres of strip-till tillage
management, 4,100 feet of field border, 150 acres of
forage and biomass planting, 2.11 acres of forage har-
vest management, one pond, one pumping plant, 486
acres of seasonal residue management, 38.2 acres of
improved irrigation efficiency through sprinkler Irriga-
tion, 5.5 acres of grassed waterway, 158 acres of nutri-
ent management, 461 acres of range planting, reduced
tillage residue and tillage management on 1,566 acres,
216 acres of integrated pest management (IPM), 770
feet of low-pressure underground irrigation pipeline,
158 acres of irrigation water management, and upland
wildlife habitat management on 1,007 acres.
Partners implemented more CPs in 2011-2015, includ-
ing 101 acres of livestock access control, 126 acres of
brush management, 240 acres of conservation cover,
4 acres of critical area planting, 6,825 feet of cross-
fencing, 2,408 acres of GPS-based precision pesticide
application and 2,459 acres of pesticide application
improvements to reduce drift, 153 acres of herbaceous
weed control, 345 acres of nutrient management,
1,852 acres of prescribed grazing and similar grazing
management practices, 560 acres of split nitrogen
applications, one pond, two wells, 276 acres of range
planting, '1,336 acres of no-till residue and tillage
management, 554 acres of IPM, 516 acres of reduced-
till or ridge-till residue and tillage management, 7,180
feet of terrace, 1,301 acres of supplement/feeding
area rotation, four water control structures, 452 acres
of irrigation systems improvements, 153 acres of
wetlands restoration and 85 acres of seasonal residue
management.
Figure 3. Otter Creek fully supports its warm water
aquatic beneficial use.
Results
Through its statewide nonpoint source Rotating Basin
Ambient Monitoring Program, the OCC documented
Improved water quality in Otter Creek. Monitoring data
compiled for the 2012 integrated report showed that
turbidity values had decreased—no baseflow samples
exceeded 50 NTU and exceedances remain weli below
10 percent for the 2016 assessment (Figure 2). On the
basis of these data, Otter Creek was removed from
the CWA section 303(d) list for turbidity in 2012; it
now fully supports its warm water aquatic beneficial
use (Figure 3). Monitoring will continue to ensure this
water quality improvement Is maintained.
Partners and Funding
The OCC monitoring program is supported in part by
the U.S. Environmental Protection Agency's (EPA) CWA
section 319 funds at an average annual statewide cost
of $1 million. Approximately $500,000 in EPA CWA 319
funds support statewide water quality educational
efforts through Blue Thumb. From 2004 to 2010, NRCS
supplied at least $25,000 through EQIP and additional
funds through CRP to implement CPs. From 2011
through early 2016, NRCS invested $700,000 in CPs
through EQIP and CSP. Additional funds were provided
through FSA for CRP practices, and through NRCS for
WFilP- and WRP-funded practices. In addition, some
practices were funded by landowners based on recom-
mendations through NRCS general technical assistance
and conservation planning. The OCC worked through
the Tillman and Kiowa county conservation districts to
provide $9,026 in LLCP funds, which were matched by
$11,439 from cooperating landowners.
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U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA 841-F-16-001P
August 2016
For additional information contact:
Shanon Phillips
Oklahoma Conservation Commission

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