Section 319
NONPOINT SOORGE PROGRAM SOGGESS STORY
Agricultural Best Management Practice Implementation Decreases
Turbidity in Gray Horse Creek
Waterbodv Improved H'9h turbidity- due in part to Practices associated with cattle
production, resulted in impairment of Gray Horse Creek and
placement on Oklahoma's Clean Water Act (CWA) section 303(d) list in 2004. Implementation
of best management practices (BMPs) to promote better quality grazing land decreased
sediment loading into the creek. As a result, the entire length of Gray Horse Creek was
removed from Oklahoma's 2010 CWA section 303(d) list for turbidity impairment. Gray Horse
Creek is now in full attainment of its fish and wildlife propagation designated use.
Problem
Gray Horse Creek is in Osage County in north
central Oklahoma (Figure 1). Land use in the
27,427-acre watershed is primarily rangeland and
pasture for cattle production. Poor grazing land
management contributed to excess sedimentation
in the watershed. In the 2004 water quality assess-
ment, monitoring showed that 18 percent of Gray
Horse Creek's seasonal baseflow water samples
exceeded 50 nephelometric turbidity 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 5 years
of data before the assessment year). On the basis
of these assessment results, Oklahoma added the
entire length of 16-mile-long Gray Horse Creek
(OK621200010400_00) to the 2004 and subsequent
CWA section 303(d) lists for nonattainment of the
fish and wildlife propagation designated use due to
turbidity impairment.
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.
From 2005 to 2009, landowners addressed erosion
from grazing lands by improving pasture condition
with 610 acres of prescribed grazing and enhancing
rangeland condition through 250 acres of brush
management. One pond was installed to provide an
alternative water source for better pasture manage-
ment. From 2010 to 2012, the NRCS Environmental
Monitoring Site
Gray Horse Creek Watershed
Figure 1. The Gray Horse Creek watershed is in north central
Oklahoma.
Quality Incentives Program and the Conservation
Stewardship Program incentivized installation of
3,085 acres of prescribed grazing, 2,021 acres of
nutrient management, 2,483 acres of integrated
pest management, and 151 acres of rotational graz-
ing, all of which promote healthy grazing lands and
reduce erosion potential.
In addition, the Oklahoma Conservation
Commission's (OCC's) education program, Blue
Thumb, has had several active volunteer monitor-
ing sites in Osage County for a number of years.
-------
Figure 2. Blue Thumb volunteers actively monitor streams
in Osage County and help educate area residents about
nonpoint source pollution and stream health.
Educational programs have been offered by Blue
Thumb staff in the county, and volunteers work to
educate watershed residents, including the Kaw
and Osage tribal nations, about nonpoint source
pollution and the status of area streams as well
(Figure 2).
Results
The OCC's Rotating Basin Monitoring Program,
a statewide nonpoint source ambient monitoring
program, documented improved water quality in
Gray Horse Creek due to landowners implement-
ing BMPs. In the 2004 assessment, 18 percent of
seasonal base flow water samples exceeded the
turbidity criteria of 50 NTU. This exceedance was
reduced to zero percent in 2010 and remained at
this level in the 2012 assessment (Figure 3). Gray
Horse Creek was removed from Oklahoma's 2010
CWA section 303(d) list for turbidity impairment
and is now in full attainment of the fish and wildlife
propagation designated use.
Gray Horse Creek
o
!5
.2
o
0)
g
OQ
100 — 18% exceedance
80-
60
40
20-
o-
0% exceedance 0% exceedance
1 I I
2004 2010 2012
Assessment Year
Figure 3. Monitoring data indicate that base flow turbidity
levels in Gray Horse Creek declined by 2010 and currently
meet water quality standards.
Partners and Funding
The Rotating Basin Monitoring Program is sup-
ported through EPA's CWA section 319 program
at an average annual cost of $1 million. Monitoring
costs fund personnel, supplies, and lab analyses
for 18 parameters from samples collected every
5 weeks at about 100 sites. In-stream habitat, fish,
and macroinvertebrate samples are also collected.
Approximately $600,000 in CWA section 319 fund-
ing supports statewide education, outreach, and
monitoring efforts through the Blue Thumb program.
The Oklahoma cost-share program provided approxi-
mately $2,000 in state funding for BMPs in this
watershed through the Osage County Conservation
District. NRCS spent approximately $677,000 for
implementation of prescribed grazing and brush
control BMPs in Osage County from 2005 to 2009
through general technical assistance funds. An
additional $300,000 was spent from 2010 to 2012
to maintain these practices and continue to pro-
mote good grazing land management. Landowners
provided a significant percentage of funding toward
BMP implementation in these programs as well.
UJ
O
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-14-001JJ
June 2014
For additional information contact:
Shanon Phillips
Oklahoma Conservation Commission
405-522-4500 • shanon.phillips@conservation.ok.gov
------- |