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NONPOINT SOURCE SUCCESS STORY

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Conservation Leadership and Land Stewardship Improve Caddo Creek

Waterbody Improved LoW pH anc' e'evatec' Escherichia coli (E. coli) and ammonia

concentrations resulted in impairment of Caddo Creek and
placement on Oklahoma's Clean Water Act (CWA) section 303(d) list of impaired waters in 2006
(ammonia) and 2008 (pH and E. coli). Pollution from cropland and grazing lands contributed to this
impairment. Implementing conservation practice systems (CPs) to promote better land management
decreased runoff of nutrients, bacteria, and other pollutants and helped to improve water quality.
As a result, Oklahoma removed the ammonia and pH impairments in 2010 and the E. coli impairment
in 2018 from its CWA section 303(d) list. Caddo Creek now fully supports its Primary Body Contact
(PBC) and partially supports its Warm Water Aquatic Community (WWAC) beneficial uses.

Problem

The Caddo Creek watershed covers approximately
224,297 acres (ac) of scenic hills, prairies and wood-
lands in Carter, Murray and Stephens counties in
Oklahoma (Figure 1). Caddo Creek is located within
the Chickasaw Nation and drains from headwaters in
southwest Stephens County to the confluence with the
Washita River northeast of Ardmore in Carter County.
Land use in the watershed is about 65% grazing lands,
23% shrub land and forested and 5% developed. The
primary agricultural products from the watershed are
cattle, hay and pecans. Between 1900 and 2022, more
than 4,500 oii and gas wells have been developed in
the watershed, approximately 3,200 of which have
been driiied or redrilied since 2005.

Water quaiity monitoring in the early 2000s deter-
mined that challenges with grazing land management
contributed to a 2006 listing of the 44.08-mile stream
as being impaired byammonia when 27% of samples
were outside the acceptable limits for toxicity based
on temperature and pH. A stream is considered to
violate standards for ammonia if more than 10% of
samples are outside the acceptable limits. Oklahoma
added pH as an impairment in 2008 when 15% of
samples were outside acceptable limits. A stream is
considered to be impaired by phi if more than 10% of
samples are less than 6.5 or greater than 9. The stream
was also listed for E. coli in 2008 when the geometric
mean of samples collected during the recreational sea-
son was 208 colonies per 100 milliliters (col/100 mL).
A waterbody is considered impaired for E. coli if the
geometric mean of samples collected between May 1
and September 30 is greater than 126 col/100 mL.

Figure 1. Caddo Creek is In southern Oklahoma.

Based on these results, Oklahoma added segment
310800030010_00 to the CWA section 303(d) iists in
2006 and 2008 for nonattainment of the WWAC and
PBC beneficial uses.

Story Highlights

The Caddo Creek watershed is home to several well-
known Oklahoma ranching operations, including the
Double C Cattle Company and Speake Ranch. These
two operations hold workshops and educational
programs that promote regenerative agriculture and
conservation-focused management. They have been
recognized with environmental awards from the
National Cattlemen's Foundation and the Sand County
Foundation. These producers and more than 130 of
their neighbors in the watershed worked with the
Arbuckle, Murray, or Stephens county conservation
districts; the Natural Resources Conservation Service

^Legend

Oil and Gas Wells

Caddo Creek Monitoring Sitel

Watershed Structures |

Sand Creek

Caddo Creek

Chickasaw Nation

Lakes

County Boundaries


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(NRCS); and the Oklahoma Conservation Commission
(OCC) to implement CPs. They worked through a vari-
ety of programs, including the OCC's State Cost Share
Program (SCSP) and NRCS's Environmental Quality
Incentives Program (EQIP), Conservation Stewardship
Program (CSP), Wetlands Reserve Program (WRP), and
general conservation technical assistance program.

From 2002 to 2020, landowners improved grazing and
animal waste management, which reduced runoff of
sediment, nutrients and other pollutants by increas-
ing vegetative cover and reducing bare soil and by
protecting animal waste from runoff. Landowners
implemented brush management (1,282 ac), conserva-
tion crop rotation (84 ac), cover crop (67 ac), critical
area planting (156 ac), diversion (7,885 feet [ft]),
fence (79,204 ft), firebreak (33,025 ft), forage harvest
management (701 ac), grade stabilization structures
(31), grassed waterways (0.2 ac), groundwater testing
(4 wells), heavy use area protection (3 ac), herbaceous
weed control (191 ac), livestock pipeline (2,000 ft),
nutrient management (1,488 ac), pasture and hayland
planting (873 ac), pest management (3,278 ac), ponds
(163), reduced tillage (797 ac), prescribed burning
(1,153 ac), prescribed grazing (38,566 ac), pumping
plants (6), range planting (25 ac), one seasonal high
tunnel, terrace (2,906 ft), tree planting (0.5 ac), upland
wildlife habitat management (2,686 ac), water control
structures (12), water wells (7), wetland wildlife habitat
management (140 ac), and wetland restoration (160
ac). In addition, at least 6,670 acres were enrolled in
CSP, which facilitated additional practices to improve
animal waste, grazing, soil and nutrient management.
TheArbuckle Rangeland Restoration Association has
also been working with landowners in the water-
shed to use controlled burns to restore and improve
rangeland habitat in the watershed by developing burn
plans, overseeing prescribed fire applications, and
educating landowners about the benefits of prescribed
fire during all seasons.

Results

The OCC documented improved water quality in Caddo
Creek due to installation of CPs through its statewide
nonpoint source Rotating Basin Ambient Monitoring
Program. By 2012, ammonia concentrations dropped
(< 8% exceeded acceptable criteria) and pH values

2012	2014	2016

Figure 2. Caddo Creek E. coli levels declined after
installation of CPs.

improved (< 9% were outside the acceptable range).
By 2018, E. coli concentrations improved to a geomet-
ric mean of 102 colonies/100 mL (Figure 2). Caddo
Creek now fully supports its PBC and partially supports
its WWAC beneficial uses, and Oklahoma removed the
following impairments from the CWA section 303(d)
list: ammonia and pH in 2010 and E. coli in 2018.

Partners and Funding

The OCC monitoring program is supported by U.S.
Environmental Protection Agency's (EPA's) CWA
section 319 funding at an average annual statewide
cost of $1 million. Approximately $500,000 in EPA 319
funds support statewide water quality educational
efforts through Blue Thumb. Approximately $627,532
of these federal and state matching funds have been
devoted to Caddo Creek.

From 2002 to 2020, NRCS invested a minimum of
$593,000 for CP implementation in Oklahoma through
EQIP; additional financial assistance was provided
through CSP and WRP. In addition, many practices
were funded by landowners based on recommenda-
tions through NRCS general technical assistance.
The OCC; Arbuckle, Murray, and Stephens county
conservation districts; and landowners funded more
than $274,647 worth of CPs (at least $112,961 of
which was funded by landowners through the SCSP).
TheArbuckle Rangeland Restoration Association has
worked with several landowners in the Caddo Creek
watershed to plan and implement prescribed fire to
improve rangeland quality and protect water quality.

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U.S. Environmental Protection Agency
Office of Water
Washington, DC

EPA 841-F-22-001EE
December 2022

For additional information contact:

Shanon J Phillips

Oklahoma Conservation Commission
405-522-4728 • shanon.phillips@conservation.ok.gov


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