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m 1 NONPOINT SOURCE SUCCESS STURY

Reducing Erosion Helped Restore Native Freshwater Mussels in
Buffalo Creek
Water bodies 1 m proved PoPu,ations of native freshwater mussels, which are indicators of
biological health in streams, declined in Buffalo Creek between
1984 and 1998 due primarily to soil erosion and sediment delivery from row cropping practices. As
a result, five segments of Buffalo Creek were listed on Iowa's Clean Water Act (CWA) section 303(d)
list of impaired waters by 2008 due to impairments of the creek's aquatic life (biological) designated
use. Support provided through the Upper and Middle Buffalo Creek Watershed Projects assisted
farmers with the installation of practices that reduced sediment loading to the creek and improved
the habitat for mussels. After a 2013 mussel survey showed mussel populations had rebounded,
the aquatic life impairments were removed from the state's list of impaired waters for five
segments of Buffalo Creek in 2014.
Problem
Buffalo Creek, a major tributary of the Wapsipinicon
River, drains a long, narrow, 146,906-acre watershed
in eastern Iowa (Figure 1). The predominant land use
in the watershed is corn and soybean production. The
creek is used for recreation by paddlers and anglers,
A freshwater mussel survey done in the creek in 1984
showed a relatively healthy total population and
species richness of freshwater mussels. A follow-up
survey done in 1998 showed that both the total mus-
sel populations and species richness had declined by
more than 50 percent, which triggered impairments in
the creek's aquatic life designated use (Figure 2). As a
result, five segments of Buffalo Creek were placed on
Iowa's impaired water's list by 2008.
A land use assessment conducted by the Upper Buffalo
Creek Project showed a pre-project estimated sedi-
ment delivery of 21,680 tons per year to the creek in
the upper portion of the watershed. Heavy sediment
loading to the creek reduced the habitat for native
freshwater mussels and was a primary cause for the
low numbers of mussel species found in 1998.
Project Highlights
In 2010-2014, the Upper Buffalo Creek Water Quality
Project, administered by the Buchanan Soil and
Water Conservation District (SWCD) in Independence,
Figure 1. Five impaired segments in eastern Iowa's
Buffalo Creek watershed have been restored.
implemented conservation practices to reduce
sediment delivery in the upper portion of the water-
shed. It was funded primarily by Iowa's Watershed
Improvement Review Board (WIRB), and by programs
administered by the Iowa Department of Agriculture
FAYETTF.
COUNTY
DELAWARE
COUNTY
Segment 1
18 miles
MASONVILLE
DELAWARE
BUCHANAN
COUNTY
QUASQIIETOX
Segment 3
7 miles
JONES
COUNTY
Segment 5
8 miles

BENTON
COUNTY
BUCHANAN
COUNTY
QUASQIIETOX
ROWLEY
DELAWARE
COUNTY
Buffalo Creek Watershed
Mussel Impairment Delistings
Delisted Creek Segments
Segment 4
10 miles

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Figure 2. Biologists conduct DNR mussel survey.
and Land Stewardship (IDALS) and the U.S. Department
of Agriculture (USDA) Natural Resources Conservation
Service (NRCS) and Farm Service Agency (FSA). The
project employed a full -time watershed project coordi-
nator to help landowners implement practices in the
watershed. Next, the Middle Buffalo Creek Project,
funded primarily by WIRB and IDALS, installed conser-
vation practices in the middle portion of Buffalo Creek
downstream for approximately one additional year.
Through the Upper Buffalo Creek Project, landowners
and farm operators installed 93 conservation practic-
es, including 68 grass waterways that addressed much
of the ephemera! gully erosion sediment delivery to
the creek. Three of the waterways included rock check
Table 1. Native mussel species found in Buffalo Creek* before
(1984,1998, 2008) and after (2012-2013) restoration.
Creek Segment
County
# of Live Mussel Species Found
Segment
ADB Code**

1984
1998
2008
2012-
2013
l
!A 01-WPS-
0130_2
Buchanan
7
2
i
5
2
IA01-WPS-
0130_1
Buchanan,
Delaware,
Linn
13
0
0
11
3
!A 01-WPS-
0110_3
Linn
10
3
2
9
4
IA01-WPS-
0110_2
Linn
16
12
Not
Sampled
11
5
IA01-WPS-
QiiOjL
Jones
11
4
Not
Sampled
7
outlet structures, which prevented classic gully sedi-
ment delivery. Other practices implemented included
cover crops, critical planting areas, filter strips, quail
buffers with native plantings, contour buffers, and an
upgraded animal waste storage facility. An additional
12 conservation practices were completed through
the Middle Buffalo Creek Project.
Results
Practices implemented through the Upper Buffalo
Creek Project reduced sediment delivered to Buffalo
Creek by an estimated 4.417 tons per year (a 20
percent reduction), which is equai to 316 dump truck
loads of sediment per year. Phosphorus levels were
reduced by an estimated 5,742 pounds per year.
Sediment and phosphorus load reduction estimates
were based on USDA NRCS Revised Universal Soil Loss
Equation calculations.
The reduced sediment delivery improved the creek
substrate (material on the creek bottom) and improved
the habitat for native mussels. The Iowa Department
of Natural Resources' (DNR's) Statewide Mussel Survey,
funded by a U.S. Environmental Protection Agency
(EPA) CWA section 319 grant, showed that the total
mussel population and number of mussel species had
rebounded significantly in Buffalo Creek (Table 1) by
2013. Of the live mussel species found in the survey,
four are on Iowa's list of threatened animal species:
cylindrical papershell, creek heelsplitter, creeper, and
ellipse. Many of the mussels found were fairly young
(less than five years old), suggesting that conditions
might have improved in the stream for mussels. As a
result, five segments of Buffalo Creek, representing
58 miles of its 59-mile length, were removed from
Iowa's impaired waters list in 2014 (see Figure 1).
Partners and Funding
* At study sites in five segments of Buffalo Creek
** Iowa Assessment Database Code
Partners providing funding and technical assistance
for the Upper Buffalo Creek Project included the
Buchanan SWCD, WIRB ($370,722), IDALS ($1,643),
NRCS Environmental Quality Incentive Program (EQIP)
($32,485), NRCS non-EQIP ($20,250), FSA Conservation
Reserve Program ($41,474), IJOBS (Iowa stimulus
funding) ($11,760), and private landowners ($323,605).
Project funding sources totaled $801,939. The Iowa
DNR statewide mussel survey was funded by an EPA
CWA section 319 grant.
* ^
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PRO"^
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U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA 841-F-17-001GG
December 2017
For additional information contact:
Jennifer Kurth
Iowa Department of Natural Resources
515-725-8381 • jennifer.kurth@dnr.iowa,gov

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