Section 319
NONPOINT SOURCE PROGRAM SOCGESS STORY
Installing Best Management Practices Improves Clear Creek
Waterbody Improved
Low dissolved oxygen (DO) and high fecal bacteria levels caused
Oklahoma to place Clear Creek on the state's Clean Water Act (CWA)
section 303(d) list of impaired waters for DO (in 2002) and Enterococcus bacteria (in 2008). Impairment
was due in part to practices associated with widespread livestock and wheat production. Implementing
best management practices (BMPs) to promote better quality grazing land and cropland decreased
sediment, nutrient and bacteria runoff into the creek. Water quality improved, prompting Oklahoma to
remove Clear Creek from the 2010 CWA section 303(d) list for the DO and Enterococcus impairments.
Problem
Clear Creek (Figure 1), in northwestern Oklahoma's
Beaver County, is a 24-mile-long tributary to the
Beaver/North Canadian River. Land use in the water-
shed includes mostly cattle and wheat production.
Poor grazing land and cropland management, as
well as a lack of healthy riparian buffer areas, con-
tributed to excess sediment, nutrient and bacteria
runoff in the watershed. Excess nutrients, in turn,
can lead to the overgrowth of nuisance algae, and
the subsequent breakdown of the algae can cause
DO levels to decrease.
Water quality assessments in 2002 showed that
30 percent of samples in Clear Creek fell below
(i.e., did not meet) state DO criteria for warm-water
aquatic communities. A waterbody is considered
impaired if more than 10 percent of samples (based
on no more than five years of data before the assess-
ment year) fall below 6.0 milligrams per liter (mg/L)
from April 1 through June 15 or below 5.0 mg/L dur-
ing the remainder of the year. On the basis of these
assessment results, Oklahoma added Clear Creek to
the 2002 and subsequent CWA section 303(d) lists
for failing to support the fish and wildlife propagation
designated use due to DO impairment.
In addition, water quality assessments in 2008
showed that the geometric mean for Enterococcus
bacteria was 60 colony forming units (CPU) per
100 milliliters water. Enterococcus species are
bacteria common in animal waste and can cause
human illness. Waterbodies with a geometric mean
above 33 CPU during the recreation season (May 1-
Sept. 30) are considered impaired for primary
body contact recreation. As a result, Clear Creek
was also placed on the CWA section 303(d) list for
Enterococcus impairment in 2008.
Figure 1. Clear Creek flows through agricultural land
in northwestern Oklahoma.
Project Highlights
Landowners implemented BMPs with assistance
from Oklahoma's locally led cost-share program and
through the local Natural Resources Conservation
Service (NRCS) Pnvironmental Quality Incentives
Program, No-Till Local Emphasis Area program,
Conservation Stewardship Program, Conservation
Reserve Program and general technical assistance
program. These projects focused on controlling
erosion and reducing nutrients and bacteria in
runoff. Because Clear Creek is in the Beaver and
Cimarron River NRCS Local Emphasis Area, some
projects have focused on increasing the amount of
water flow in these rivers, primarily through removal
of brush species. Increased water flow can lead to
increased DO levels.
From 2005-2011, producers in the Clear Creek
watershed implemented BMPs to address cropland
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erosion, including planting 3,046 acres of cover
crops; adding 1,775 acres in conservation crop rota-
tion; installing 60,075 feet of terraces and 155 acres
of grassed waterways; and using no-till, strip-till,
mulch-till or deep-till on 6,306 acres. Harvest
management occurred on 609 acres of cropland,
with forage planting on 155 acres. To improve the
condition of grazing lands, and thus reduce ero-
sion, producers implemented prescribed grazing on
2,311 acres and developed nutrient management
plans for 6,649 acres. Producers planted supplemen-
tal range vegetation on 230 acres, improved upland
wildlife habitat management on 1,554 acres, con-
ducted brush management on 246 acres and estab-
lished integrated pest management on 5,592 acres.
Five wells and 10 watering facilities were installed to
provide alternative water supplies to livestock.
Results
The Oklahoma Conservation Commission's Rotating
Basin Monitoring Program, a statewide nonpoint
source ambient monitoring program, documented
improved water quality in Clear Creek after res-
toration efforts. Implemented practices and the
accompanying education of landowners helped
reduce nutrients entering the stream, which in turn
improved levels of DO because algae were less
likely to be overgrown and die off.
To meet state DO criteria for warm-water aquatic
communities, Clear Creek samples may not fall
below critical DO levels (5.0 or 6.0 mg/L, depending
on the season) more than 10 percent of the time.
Data collected for the 2010 and 2012 assessments
showed that only five percent of samples fell below
the critical DO level, which met state DO criteria
(Figure 2). In addition, water quality assessment data
showed that the Enterococcus geometric mean fell
from a high of 60 CFU in 2008 to 28 CFU in 2010,
which meets the state criteria of 33 CFU (Figure 3).
On the basis of these data, Oklahoma removed
Clear Creek from the 2010 CWA section 303(d) list
for the DO and Enterococcus impairments. Clear
Creek fully supports its designated uses.
Partners and Funding
The Rotating Basin Monitoring Program, which
includes both fixed and probabilistic components,
is supported with U.S. Environmental Protection
Agency (EPA) CWA section 319 funds at an aver-
age annual cost of $1 million. Monitoring costs
include personnel, supplies and lab analysis for
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