Section 319
NONPOINT SOURCE PROGRAM SOGGESS STORY
Installing Best Management Practices and Removing Silt Improved
Bluegill Habitat in Yellow Smoke Lake
Waterbody Improved
Shoreline erosion and runoff from local farms contributed
excess sediment that negatively affected fish populations in
Iowa's Yellow Smoke Lake, prompting the state's Department of Natural Resources (DNR)
to add the lake to its Clean Water Act (CWA) section 303(d) list of impaired waters in 1998
for an aquatic life impairment. Landowners and farm operators installed terraces and grade
stabilization structures to reduce runoff from the lake's watershed. The Crawford County
Conservation Board (CCCB) also removed silt from the lake. These improvements restored
the lake's aquatic life designated use, allowing DNR to classify Yellow Smoke Lake as
restored in 2012.
Problem
Yellow Smoke Lake is a 38.4-acre reservoir in
the Boyer River watershed in west central Iowa's
Yellow Smoke Park (Figure 1). The park is a popular
location for camping, hiking, fishing, swimming,
and boating. Constructed impoundments like
Yellow Smoke Lake often have steeply sloped
shorelines which limit the amount of shallow-
water spawning habitat available for nesting and
reproduction by Centrarchid (sunfish) species,
such as bluegills. Additionally, these shallow-water
spawning areas are usually in the upper reaches of
an impoundment, where sediment-laden drainage
from the watershed enters the lake.
In the late 1990s and early 2000s, the deposition of
sediment from the watershed affected the ability of
bluegills to spawn in Yellow Smoke Lake by making
the water too shallow or by burying the eggs and
suffocating them. The sediment originated from
the inflow of agricultural runoff, as well as from
shoreline erosion made worse by heavy foot traffic
from campers and anglers. Fish survey data col-
lected by DNR Fisheries in the mid-1990s showed
that Yellow Smoke Lake failed to support its aquatic
life designated use. As a result, DNR added the
lake to Iowa's CWA section 303(d) list of impaired
waters in 1998. Although the entire lake was listed
as impaired, most of the sediment deposition was
occurring in the northeast portion of the lake.
Figure 1. Yellow Smoke Lake watershed BMPs
include sediment basins and terraces.
Project Highlights
Because no numeric criteria for siltation that
applied to Yellow Smoke Lake or its sources
existed, DNR developed a total maximum daily
load (TMDL) in 2001 on the basis of the existing
DNR Fisheries survey data. The TMDL stated that
restoring water quality in Yellow Smoke Lake would
require (1) that silt be removed from the lake and
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Figure 2. Riprap was added to stabilize almost 2,000 linear
feet of the upper east arm of Yellow Smoke Lake.
(2) that sediment retention structures be put in
place to prevent sediment from entering the lake
through watershed runoff. The success of restora-
tion efforts would be measured on the basis of
improvements in affected fish populations.
Per the TMDL recommendations, watershed
stakeholders implemented a variety of restora-
tion measures to restore Yellow Smoke Lake's
aquatic life designated use. The CCCB and the
U.S. Department of Agriculture's Natural Resources
Conservation Service worked with private landown-
ers to install 52,000 feet of terraces, 12 sediment
basins, and five ponds (see Figure 1). In addition,
beginning in 2003, the CCCB was awarded multiple
grants to restore bluegill spawning grounds with in-
lake improvements. Over a six-year period, 375 tons
of washed concrete sand was placed on the bottom
of shallow-water areas in the north arm of Yellow
Smoke Lake to create suitable spawning habitat.
CCCB removed 10,000 cubic yards of sediment
from the lake, armored 1,930 feet of shoreline to
curtail erosion in the high-foot-traffic area (Figure 2),
and built two silt-control structures to intercept silt
before it reached the lake. All of these practices led
to improved bluegill spawning habitat.
Results
A fishery survey conducted by DNR Fisheries staff
in 2010 demonstrated that fish populations had
become well balanced and healthy, and that natural
sunfish reproduction was occurring consistently.
Electrofishing samples indicated a relatively strong
size class of bluegill in the 8-to 9.45-inch size
7
s;
LL. D
£
I
2.5 3 3.5 4
4.5 5 5.5 6 6.5
Total length (in)
7 7.5
8.5 9
Figure 3.Length frequency of bluegill in Yellow Smoke
Lake, May 2010 (n = 40).
range, with several strong size classes centered
around 3.5 and 5 inches (Figure 3). The relatively
high abundance of bluegill in the smaller size
classes indicated consistent reproduction, which
bodes well for future survival and growth of the fish
population.
The DNR Fisheries staff observed that sunfish
were nesting, noted that the protected shorelines
of Yellow Smoke Lake were remaining stable, and
confirmed that the areas dredged in the upper east
end of the lake were remaining intact.
As stated in the TMDL, success can be measured
by the response of the aquatic life to improvements
made to the watershed and lake. The fishery survey
indicated that the sunfish species, which were of
primary concern for the lake restoration project, had
responded to the lake improvements by reproduc-
ing successfully and by providing good recreational
fishing opportunities for anglers. On the basis of
these data, DNR classified Yellow Smoke Lake as
restored in 2012. Yellow Smoke Lake now fully sup-
ports its aquatic life designated use.
Partners and Funding
The CCCB undertook most of the restoration work;
the Crawford County Soil and Water Conservation
District and local farm landowners and operators
performed additional work. The CCCB was awarded
$127,000 from DNR's fish habitat grant program
between 2004 and 2009. The Iowa Department
of Agriculture and Land Stewardship's Watershed
Protection and Resource Enhancement and
Protection program invested $70,000 in best manage-
ment practice implementation on private land. Iowa
DNR's CWA section 319 program provided technical
assistance for the TMDL, and DNR Fisheries provided
technical assistance for in-lake improvements.
VSSy
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-14-001D
January 2014
For additional information contact:
Ben Wallace
Iowa Department of Natural Resources
712-657-2638 • Ben.Wallace@dnr.iowa.gov
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