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NONPOINT SOURCE SUCCESS STORY
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Watershed Projects Reduce Sediment in a Segment of the Big Sioux River
Waterbody Improved
Sedimentation from agricultural nonpoint source pollution degraded
warmwater semipermanent fish habitat in a 49.77-mile segment
(Segment Four) of the Big Sioux River. As a result, the South Dakota Department of Environment and
Natural Resources (DENR) placed the waterbody on South Dakota's 2008 Clean Water Act (CWA) section
303(d) list of impaired waters for total suspended solids (TSS) impairment. Partners implemented seven
CWA section 319 implementation projects spanning the Upper Big Sioux watershed, which reduced
sediment levels. Due to these improvements, DENR reclassified the segment in 2010 as meeting its
beneficial uses for warmwater semipermanent fish life and removed it from the CWA section 303(d) list.
Problem
The Big Sioux River, a major river in eastern South
Dakota, drains some of the most populated and
intensely farmed areas in the state (Figure 1). Many
of the 17 segments of the 418-mile river are desig-
nated as impaired waters due to nutrients, dissolved
oxygen, bacteria and TSS. To meet water quality
standards for TSS, the 30-day average TSS concen-
trations must be less than or equal to 90 milligrams
per liter (mg/L) and the daily maximum must not
exceed 158 mg/L more than 10 percent of the time.
Water quality monitoring during the North Central Big
Sioux River Watershed Assessment from 2001-2006
showed that Segment Four of the Big Sioux River
(segment ID SD-BS-R-BIG _ SIOUX _ 04; Stray Horse
Creek to Near Volga; 49.77 miles) violated these
standards. As a result, DENR added the segment to
the state's list of impaired waters in 2008 for failure
to attain its beneficial uses for warmwater semiper-
manent fish life due to elevated TSS. Segment Four
drains 3,032 square miles of northeast South Dakota
before continuing downstream south of Volga.
Project Highlights
Multiple implementation projects from 2006 to the
present contributed to water quality improvements
in the Upper Big Sioux River. The Upper Big Sioux
River Project was initiated to reduce sediment and
nutrient loads to Lake Kampeska and was later
expanded to include improvements to the Big Sioux
River, upstream of Segment Four. The Lake Poinsett
Project reduced nutrient and sediment loading to the
lake, improving water quality in the northern part of
Segment Four. The Central Big Sioux Project, now
named the Big Sioux River Watershed Implementation
Project (a total maximum daily load [TMDL] imple-
mentation project), addressed water quality impair-
ments in the southern portion of Segment Four.
Best Management Practices
in the Big Sioux Segment 4 Watershed
Best Management Practices
Ag Waste System
Bank Stabilization
Critical Area Planting
Cropland BMPs
Grassed Waterways
Grazing Management
Riparian Area Management (RAM)
Riparian Restoration/Protection r
Sediment Traps
o Wetland Restoration
• Water Quality Monitoring Stations
Big Sioux Segments 1-3
— Restored Big Sioux Segment 4 -—
— Big Sioux Segments 5-8 Kingsbliry
• Upper Big Sioux Waterbodies County
Streams
en Big Sioux Four Subwatershed n c in
en Upper Big Sioux Watershed
Figure 1. Location of the Upper Big Sioux Watershed and Best
Management Practices. Segment Four was listed as impaired
for TSS in the 2008 Integrated Report from Stray Horse Creek
to Volga, shown in red. Segments 5-8 shown in brown remain
impaired for TSS and continue southward off the map.
Other CWA section 319-funded projects in the Big
Sioux River basin include the statewide CWA section
303(d) Watershed Planning and Assistance Project,
Northeast Glacial Lakes Watershed Improvement
and Protection Project, East Dakota Riparian Area
Restoration and Protection Project, and Deuel County
Lakes Watershed Improvement Project. Through
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Figure 2. Farm Service Agency imagery from 2004 and
2014 shows improved riparian function on 4.3-acre
grassed easement on former crop ground along the
Big Sioux River. Hayed area is outside the easement.
these seven projects, 51 agricultural waste systems,
114 bank stabilizations, two critical area plantings,
11 grassed waterways, 26 grazing management
practices, six riparian area management practices,
46 riparian restoration practices, 100 sediment traps
and two wetland restorations were installed through-
out the Upper Big Sioux Watershed (Figure 2).
Results
As of 2010, Segment Four's TSS values no longer vio-
lated water quality standards and the waterbody was
removed from the state's CWA section 303(d) list. This
improvement can be seen in Figure 3, which shows
the decreases in the percent exceedances of the daily
maximum pollutant levels forTSS (from 11 percent in
1998-2005 down to 3 percent in 2006-2015) which
meets the water quality standards. As of June 2015,
nitrogen has been reduced by 234,850 pounds (Ibs),
phosphorus by 59,859 Ibs, and sediment by 14,254
tons peryear across the Upper Big Sioux drain-
age according to the STEPL (Spreadsheet Tool for
Estimating Pollutant Load) model.
Partners and Funding
Local sources were used to fund the majority of
water quality improvements, including grassed
waterways, sediment dams and alternative water
sources to exclude cattle from the streams. CWA
section 319 funds supported riparian grazing man-
agement, information and education, water quality
monitoring as well as agricultural waste systems
which reduce more nutrients than sediment.
Total Suspended Solids in Big Sioux, Segment Four
mg/L percent
80n 12
60-
pre-BMP (1998-2005)
^H average TSS mg/L
post-BMP (2006-2015)
• exceedance of standard
1
Figure 3. Average TSS concentrations and percent
exceedances of 158 mg/L calculated from six water
quality monitoring stations along Segment Four. (Error
bars show standard deviation.) Segment Four supports
beneficial uses for fish/wildlife propagation, irrigation
water, limited contact recreation and warmwater
semipermanentfish life.
Hard work and funds from local, state and federal
agencies and committed landowners restored
Segment Four of the Big Sioux River. The par-
ticipating projects funded BMP installation totaling
$4,436,327. CWA section 319 funds contributed
$588,178 to BMP implementation while $685,913
was from other federal sources. State, local and in-
kind sources provided $3,162,237.
Local partners included participating landowners;
the city of Watertown; Watertown Municipal Utilities;
Kampeska Water Project District; Lake Pelican Water
Project District; Lake Pelican Preservation Society;
Lake Area Technical Institute; Isaak Walton League of
America, Northern Prairies Land Trust; East Dakota
Water Development District; Lake Poinsett Water
Project District; Lake Poinsett Sanitary District; Lake
Poinsett Development Association; Hamlin County
Livestock Improvement Association; KWAT radio
(Watertown); and Brookings, Codington, Deuel,
Hamlin and Kingsbury County Conservation Districts.
Statewide partners included the South Dakota
Department of Game, Fish and Parks; South Dakota
Department of Environment and Natural Resources;
South Dakota State University; South Dakota
Association for Conservation Districts and the South
Dakota Discovery Center. National partners included
the U.S. Environmental Protection Agency, U.S. Fish
and Wildlife Service, U.S. Department of Agriculture
(Farm Service Agency and Natural Resources
Conservation Service), and Ducks Unlimited.
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EEPA841-F-15-001FFF
December 2015
For additional information contact:
Barry McLaury
SD Dept. of Environment and Natural Resources
605-773-4254 • barry.mclaury@state.sd.us
Al Basile
USEPA Region 8
303-312-6551 • basile.alfred@epa.gov
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