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Section 319
NONPOINT SOURCE PROGRAM SOCGESS STORY
Implementing Erosion Control and Stream Restoration Projects Improves
Aquatic Habitat in Big Creek
Waterbodv Imoroved Sedimentfromforestl°99in9 roads and other ground-disturbing
• - ' r- v - activities degraded water quality in Montana's Big Creek. As a
result, the Montana Department of Environmental Quality (MDEQ) added Big Creek to the state's
Clean Water Act (CWA) section 303(d) list of impaired waters in 1992. A number of public and
private partners collaborated to implement erosion control best management practices (BMPs)
and other stream restoration projects in the Big Creek watershed. Recent monitoring data from
Big Creek show improvements in aquatic life and overall water quality. On the basis of these data,
MDEQ will remove the segment from the state's list of impaired waters for sediment in 2012.
Problem
The Big Creek watershed, in the Rocky Mountains
of northwestern Montana, includes Upper and
Lower Big Creek, Hallowat Creek and Skookoleel
Creek (Figure 1). Big Creek is a 15.7-mile-long
tributary of the North Forth of the Flathead River.
The stream is designated for aquatic life and cold-
water fishery use and includes important spawning
habitat for the endangered bull trout.
Extensive logging activities on public and private
lands in the watershed (largely in the 1950s and
1960s) generated excessive sediment loading in the
creek through the late 1970s and 1980s. Increased
runoff following the timber harvest caused stream
bank instability and increased stream channel
erosion in Big Creek and its tributaries. In 2001, the
Moose Fire burned through much of the watershed,
further altering sediment and water dynamics. The
development of ski runs in the watershed's head-
waters also contributed to sediment loading.
MDEQ used the Pfankuch Stream Channel Rating,
a measure of stream bank stability based on 15 sta-
bility indicators, to assess the overall condition of
the stream's characteristics. Segments of Big Creek
were rated as "good" in the late 1970s, but many
segments received a "fair" or "poor" rating in 1982.
MDEQ also used the riffle stability index (RSI), a
measure of the percentile of mobile particles in the
riffle section of the stream, to estimate sediment
loading in the waterbody. A score of 70 or greater
indicates that a stream is losing stability. In 1993
several samples from Big Creek had scores greater
than 70, including three above 90. Between 1980
Big Creek Watershed, Montana
Big Creek Watershed
Montana
J
Figure 1. The Big Creek Watershed is in Montana's Rocky
Mountains.
and 1990, the percentage of fine sediments in the
streambed increased from 23 to 53 percent, indicat-
ing an increase in sediment loading. Based on these
and other water quality data, MDEQ added Big
Creek to the state's 1992 CWA section 303(d) list as
impaired by sediment.
Project Highlights
In the 1980s and 1990s the U.S. Forest Service
(USFS) acquired all private lands in the upper
watershed. Early watershed planning efforts led the
USFS Glacier View-Hungry Horse Ranger District
staff to develop a document titled Environment
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Evaluation at the Watershed Scale in 1999. This
planning approach identified key action items for
restoration, specifically aimed at reducing sediment
levels in bull trout spawning areas; it also provided
the basis for the Big Creek Watershed Restoration
Plan developed in 2003.
MDEQ submitted the Big Creek Watershed
Restoration Plan to EPA to fulfill requirements for
a total maximum daily load (TMDL) in 2003. The
Restoration Plan/TMDL sediment target required
that channel substrate core samples contain less
than 30 percent fines smaller than 6.35 millimeters.
The Restoration Plan/TMDL also outlined three
major criteria for assessing water quality improve-
ment: (1) determine whether sediment reduction
activities have been implemented as outlined in the
TMDL; (2) show that water quality standards for
sediment are being met; and (3) demonstrate that
the aquatic life use is no longer impaired.
Over the past 15 years, USFS implemented a
number of restoration activities aimed at reducing
sediment loading in Big Creek. Between 1995
and 2008, it decommissioned 60.6 miles of
road and removed 47 culverts. Between 2002
and 2005, it implemented BMPs on 89 miles of
road in accordance with both Montana's and the
U.S. Fish and Wildlife Service's Inland Fish Strategy
standards, enlarged 16 culverts, installed three new
arch culverts, and built two new bridges to replace
culverts.
To prevent erosion in disturbed riparian areas, proj-
ect partners planted vegetation on stream terraces
to help secure eroding banks. During the 1990s,
the Montana Department of Fish, Wildlife and
Parks (MFWP) added large logs to the headwater
tributaries to help restore natural stream functions,
further reducing erosion and sediment input into
the stream. The Montana Conservation Corps also
stabilized 34 acres of upland eroding areas.
Results
MDEQ, USFS and MFWP have assessed post-project
water quality and aquatic life health according to
five parameters related to sediment conditions—
residual pool depth, composition of stream bottoms
as measured by pebble count, stability of stream
bottoms, amount of fine sediment in bull trout
spawning areas, and ecological health of aquatic
insect communities. Three of the parameters
(residual pool depth, composition of stream
Figure 2. This stretch of Upper Big Creek now
supports healthy bull trout spawning habitat.
bottoms, and macroinvertebrate sampling) indicate
thatfine sediment is no longer limiting the viability
of aquatic life communities in Big Creek.
While Big Creek does not yet meet the fine
sediment TMDL target (samples must contain less
than 30 percent fine sediment), subsurface fine
sediment data indicate water quality improvement.
The current 5-year running median is 32.3 percent,
and the most recent annual fine sediment value
(2009) is 31.4 percent, similar to values expected
in reference, undeveloped watersheds. These
current percentfine sediment data are below the
35 percent threshold at which FWP and USFS
consider bull trout spawning threatened. The state
has concluded that subsurface fine sediment is no
longer limiting the fishery and aquatic life beneficial
uses (Figure 2). As a result, MDEQ will remove Big
Creek from the state's 2012 list of impaired waters
for sediment.
Partners and Funding
Partners included USFS, MFWP, MDEQ, Montana
Conservation Corps, Hungry Horse-Glacier View
Ranger District Planning Team, and the public. Each
partner contributed funds and staff time toward
the restoration of Big Creek. Because the Big Creek
watershed is managed by USFS, that agency con-
tributed the greatest amount of time and funding for
restoration projects. MDEQ used CWA section 319
funds and contributed staff time and resources to
develop the TMDL and to conduct monitoring and
assessment activities.
I
c
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-12-001C
February 2012
For additional information contact:
Robert Ray
Watershed Protection Section Manager
Montana Department of Environmental Quality
406-444-5319 • rray@mt.gov
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