Section 319
NONPOINT SOORCE PROGRAM SUCCESS STORY
Implementing Agricultural Best Management Practices Reduces Turbidity
Waterbody Improved
Excess turbidity due in part to practices associated with cattle
production impaired a portion of Oklahoma's California Creek.
As a result, Oklahoma added California Creek to the state's 2004 Clean Water Act (CWA)
section 303(d) list of impaired waters for turbidity. Implementing best management prac-
tices (BMPs) helped reduce erosion from grazing lands, and turbidity levels decreased. As a
result, California Creek was removed from the CWA section 303(d) list for turbidity in 2008.
Problem
California Creek is in Nowata County in the north-
eastern part of Oklahoma (Figures 1 and 2). Land
use in the watershed is primarily cow/calf produc-
tion. Sediment from eroding grazing lands contrib-
uted to turbidity in California Creek. Contributing
to the erosion problem was a lack of pasture and
range cover because of an overgrowth of invasive
weeds such as musk thistle, serecia lespedeza
and eastern red cedar. Sediment eroding from the
watershed's small amount of cropland also contrib-
uted to elevated turbidity levels.
Monitoring showed that seasonal base flow water
samples exceeded 50 nephelometric turbidity
units (NTU) in 2004 (by 13 percent) and 2006 (by
16 percent). A stream is considered impaired by
turbidity if 10 percent or more of the seasonal base
flow water samples exceed 50 NTUs (based on five
years' worth of data prior to the assessment year).
The high turbidity levels prevented California Creek
from attaining the warm water aquatic community
subcategory of the fish and wildlife propagation
designated use, prompting Oklahoma to add a
25-mile segment of California Creek to the 2004
CWA section 303(d) list of impaired waters.
California Creek Watershed
Figure 1. The California Creek watershed is in northeast
Oklahoma.
Project Highlights
Landowners implemented numerous BMPs with
support from Oklahoma's locally led cost-share pro-
gram and Natural Resources Conservation Service
(NRCS) programs such as the Environmental Quality
Incentives Program, Conservation Reserve Program,
Grassland Reserve Program and Wildlife Habitat
Incentives Program (WHIP). From 2003 to 2007, land-
owners implemented prescribed (managed) grazing
on 11,901 acres, which included installing 20,960 lin-
ear feet of cross-fencing and constructing 11 ponds.
Figure 2. This stretch of Oklahoma's California Creek
supports a well-established riparian area.
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Landowners planted hay and pasture vegetation on
295 acres to enhance the quality of grazing lands.
To address the invasive weed problem, they began
weed management efforts on 19,856 acres and
conducted prescribed burning on 3,358 acres.
Landowners also adopted several cropland BMPs,
including converting 456 acres of land from con-
ventional tillage to conservation tillage, implement-
ing conservation/cover crop rotation on nearly
500 acres, constructing two diversions, adding
6 acres of grassed waterways, building 11,370
feet of terraces and adopting nutrient manage-
ment plans for 428 acres. Landowners established
riparian buffers using WHIP funds, which helped to
reduce erosion and enhance wildlife habitat.
Landowners implemented additional BMPs in
2008 and 2009 that built on the initial grazing
land improvements. Recent BMPs included more
conservation tillage (152 acres), conservation crop
rotation (198 acres), fencing (17,604 linear feet),
pasture planting (343 acres), nutrient management
(390 acres), prescribed grazing (3,439 acres) and
terraces (5,685 feet).
Results
The Oklahoma Conservation Commission's (OCC's)
statewide nonpoint source ambient monitoring
program, known as the Rotating Basin Monitoring
Program, documented water quality improvements
in California Creek. As a result of the implemented
practices, turbidity levels decreased in the California
Creek watershed. In the 2008 assessment, no
samples exceeded the 50 NTU turbidity criterion
(Figure 3), prompting Oklahoma to remove California
Creek from the 2008 CWA section 303(d) list of
impaired waters for turbidity. California Creek now
partially meets its fish and wildlife propagation
designated use.
Partners and Funding
OCC's Rotating Basin Monitoring Program, which
now includes a probabilistic component, is funded
using U.S. Environmental Protection Agency (EPA)
CWA section 319 funds at an average annual cost
of $1 million. Monitoring costs fund personnel, sup-
plies and laboratory analysis for 19 parameters from
samples collected every 5 weeks at about 100 sites
for a total of 20 episodes per 5-year cycle. In-stream
habitat, fish and macroinvertebrate samples are
also collected. Approximately $600,000 in EPA
section 319 funds supports statewide education,
outreach and monitoring efforts through the Blue
Thumb program.
The Oklahoma cost-share program provided $15,711
in state funding for BMPs in the watershed, and
landowners contributed nearly $24,000. NRCS
invested approximately $335,203 to implement
BMPs in the area from 2003 to 2007 and just over
$640,000 for additional BMPs in 2008 and 2009.
S loo-
Turbidity
O O
California Creek
13% exceedance 16% exceedance 0% exceedance
•
. .
• • .,•
>• Y •
tt *• * •
2004 2006 2008
Assessment Year
Figure 3. Turbidity levels in California Creek declined from
2004 to 2008. The creek now meets the turbidity water
quality standard.
<
30
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-10-001E
March 2010
For additional information contact:
Shanon Phillips
Water Quality Division
Oklahoma Conservation Commission
shanon.phillips@conservation.ok.gov
405-522-4500
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