Section 319
NONPOINT SOURCE PROGRAM SOGGESS STORY
Changing Road Design and Implementing Grazing BMPs Reduce Sediment
\A/3t6rbody ImprOVGd Runoff from an eroding forest road and from upstream areas
of uncontrolled cattle grazing caused heavy siltation of the
lower portion of Wyoming's Hunter Creek. When the creek failed to meet its designated
use for coldwater game and aquatic life, the Wyoming Department of Environmental
Quality (WDEQ) and the U.S. Forest Service (USFS) initiated a management plan to address
these pollutant sources. The partners implemented best management practices (BMPs),
including establishing a riparian area along the stream, digging a ditch to convey runoff
away from the stream and building stream crossings for cattle upstream. As a result, sedi-
ment loads diminished, and Hunter Creek now fully supports its designated uses. WDEQ
removed Hunter Creek from Wyoming's 2004 303(d) list of impaired waters for sediment.
Problem
Project Highlights
Hunter Creek is a small (approximately 1.9 miles
long) tributary to Clear Creek, in the Powder River
Basin of the Bighorn Mountains of Wyoming. For
the purpose of surface water monitoring, WDEQ
divides Hunter Creek into upper and lower sections.
WDEQ placed the lower section of Hunter Creek
on the state's 1998 Clean Water Act (CWA) sec-
tion 303(d) list because of heavy siltation, which
threatened aquatic life by eliminating important
streambed habitats. WDEQ identified that the likely
sediment sources included the close proximity of
an adjacent road and intensive upstream cattle
grazing.
Lower Hunter Creek is classified as a Class 2AB
waters, which are those known to support game
fish. Excess sediment caused the creek to vio-
late the state's narrative standard, which states,
"floating and suspended solids attributable to or
influenced by the activities of man shall not be
present in quantities which could result in signifi-
cant aesthetic degradation, significant degradation
of habitat for aquatic life, or adversely affect public
water supplies, agricultural or industrial water use,
plant life or wildlife."
To address the two primary pollutant sources—
sediment from the adjacent road and intensive
upstream cattle grazing—WDEQ and the USFS
initiated a management plan. To reduce sediment
inputs from the road,
the partners removed
mineral outcrops from
along the road's edges,
thus allowing the road to
be shifted several feet
away from the stream
(see Figures 1 and 2).
Then, they established
a riparian buffer zone in
the newly created space
using both mineral
particles and vegetation
to separate the stream
from the road (Figure 2).
Finally, they constructed
a new road section that
channeled water away
from the stream and into
a newly dug ditch that
terminated in a sedi-
ment basin (Figure 3).
Figure 1. Hunter Creek before the
project.
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To address the second pollution source (uncon-
trolled cattle grazing), the team constructed desig-
nated cattle stream crossings upstream and began
scheduling grazing permits on a rotating basis.
The project team expects that these two grazing
BMPs will further facilitate the reestablishment of a
healthy riparian zone and lessen bank erosion along
lower Hunter Creek.
Results
After completing the road construction project
in the early summer of 2003, the amount of fine
sediment in lower Hunter Creek declined. Before
the project, sediment covered approximately 57
percent of the streambed in the study reach; within
one year of implementing the BMPs, sediment
covered only 38 percent of the streambed. With the
reduction in new sediment inputs to this stream,
the project team expects that spring runoff from
snowmelt will continue to remove preexisting mate-
rial. WDEQ determined that the road modifications
and changes in maintenance have reduced sedi-
ment impacts and that lower Hunter Creek now fully
supports all its aquatic life uses. Therefore, WDEQ
removed lower Hunter Creek from Wyoming's
303(d) list in 2004 for sediment.
Partners and Funding
A total of $675,000 in annual CWA section 319 per-
formance partnership grants funded Hunter Creek
effectiveness monitoring. These funds supported
WDEQ 319 grant program staff that worked with
the USES to implement this project.
Figure 2. Photo
of the project
site taken
immediately
after WDEQ and
USES realigned
the road and
established a
wider buffer
area. A white
mesh placed on
the new riparian
area will help
hold the soil
until vegetation
can become
established.
Figure 3. A newly-constructed ditch along the road con-
veys water away from stream and into a sediment basin.
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-08-001U
September 2008
For additional information contact:
Jack Smith
Wyoming Department of Environmental Quality
307-673-9337 • jsmith@wyo.gov
U.S. Department of Agriculture, U.S. Forest Service
Bighorn National Forest
307-674-2600
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