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Section 319
NDNPDINT SOURCE PROGRAM SOGGESS STORY
Crooked Creek Attains Designated Use after Agricultural Best
Management Practice Implementation
Waterbody Improved
High turbidity, due in part to practices associated with wheat
and cattle production, resulted in impairment of Crooked
Creek and placement on Oklahoma's Clean Water Act (CWA) section 303(d) list in 2006.
Implementation of best management practices (BMPs) to reduce erosion from cropland
and to promote better quality grazing land decreased sediment loading into the creek. As
a result, the entire length of Crooked Creek (33 miles) was removed from Oklahoma's 2010
CWA section 303(d) list for turbidity impairment. Crooked Creek is now in full attainment of
its fish and wildlife propagation designated use.
Problem
Crooked Creek is in Grant County in northern
Oklahoma, with its headwaters located just across
the border in Kansas. Land use in the 130,000-acre
watershed is primarily wheat production and graz-
ing lands for cattle, with a small amount of corn pro-
duction as well. Large tracts of cropland, coupled
with poor grazing land management, contributed to
excess sedimentation in the watershed. In the 2006
water quality assessment, monitoring showed that
20 percent of Crooked Creek's seasonal baseflow
water samples exceeded 50 nephelometric turbid-
ity units (NTU). A stream is considered impaired by
turbidity if more than 10 percent of the seasonal
base flow water samples exceed 50 NTU (based on
five years of data before the assessment year). On
the basis of these assessment results, Oklahoma
added the 33-mile-long Oklahoma segment of
Crooked Creek (OK621000060010 _ 00) to the
2006 and subsequent CWA section 303(d) lists for
nonattainment of the fish and wildlife propagation
designated use due to turbidity impairment.
Crooked Creek Watershed
Project Highlights
Landowners implemented BMPs with assistance
from Oklahoma's locally led cost-share program and
through the local U.S. Department of Agriculture's
Natural Resources Conservation Service (NRCS)
general Conservation Technical Assistance
Program, Conservation Reserve Program (CRP)and
Environmental Quality Incentives Program (EQIP).
From 2006 to 2009, landowners reduced erosion
Figure 1. The Crooked Creek watershed is in
northern Oklahoma.
potential from cropland with conservation tillage
methods: nearly 6,000 acres of no-till, strip-till, and
mulch-till, in addition to 1,856 acres of conserva-
tion crop rotations, 475 acres of residue manage-
ment and more than 1,000 acres of cover crops.
To slow erosion on sloped cropland, 35 acres of
contour farming, 63 acres of grassed waterways,
73,661 feet of terraces and one grade stabilization
structure were installed. Proper nutrient manage-
ment was implemented on 2,125 acres of cropland.
Project participants improved pasture and range
conditions with 2,944 acres of prescribed graz-
ing, installation of two ponds for alternative water
sources, 9,680 linear feet of fencing, 3,243 acres
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of supplemental range planting and 4,200 acres of
upland wildlife habitat management.
BMP implementation continues in the watershed.
From 2010 to 2012, 6,421 acres of no-till and
reduced-till crop production occurred, along with
41 acres of cover crops, 1,282 acres of conserva-
tion crop rotations, and 169 acres of forage plant-
ing and harvest management. Two more grade
stabilization structures were installed, along with
two diversions, 15 acres of grassed waterways and
9,168 feet of terraces. To optimize grazing condi-
tions, landowners practiced prescribed grazing on
7,786 acres, planted supplemental vegetation on
46 acres, installed 12 watering facilities and two
additional ponds, and managed 1,530 acres of
upland wildlife habitat.
Results
The Oklahoma Conservation Commission's Rotating
Basin Monitoring Program, a statewide nonpoint
source ambient monitoring program, documented
improved water quality in Crooked Creek due to
landowners implementing BMPs. In the 2006
assessment, 20 percent of seasonal base flow
water samples exceeded the turbidity criteria of
50 NTU. This exceedance was reduced to zero per-
cent in 2010, and Crooked Creek was removed from
Oklahoma's CWA section 303(d) list for turbidity
impairment. Crooked Creek is now in full attainment
of the fish and wildlife propagation designated use.
Partners and Funding
The Rotating Basin Monitoring Program is support-
ed by the U.S. Environmental Protection Agency's
CWA section 319 program at an average annual cost
of $1 million. Monitoring costs include personnel,
supplies and lab analyses for 18 parameters from
Crooked Creek
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20%exceedance
0%exceedance
• • •
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2006 2010
Assessment Year
Figure 2. Monitoring data indicate that base flow turbidity levels
in Crooked Creek have declined.
samples collected every 5 weeks at about 100 sites.
In-stream habitat, fish and macroinvertebrate sam-
ples are also collected. Approximately $600,000
in CWA section 319 funding supports statewide
education, outreach and monitoring efforts through
the Blue Thumb program. The Oklahoma cost-
share program provided approximately $3,249 in
state funding for BMPs in this watershed through
the Grant County Conservation District. The NRCS
spent approximately $1.8 million for implementation
of BMPs in Grant County from 2006 to 2009. An
additional $1 million was spent from 2010 to 2012 to
maintain these practices and continue to promote
conservation tillage and good grazing land man-
agement in Grant County. Landowners provided
a significant percentage of funding toward BMP
implementation in these programs as well.
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(9
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-14-001ZZ
September 2014
For additional information contact:
Shanon Phillips
Oklahoma Conservation Commission
405-522-4500 • shanon.phillips@conservation.ok.gov
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