Impaired Water - Lake Wissota (Little Lake Wissota)
Chippewa County, Wisconsin
LC19, LC21
2152800
395.79
Water is impaired due to one or more pollutants and associated quality impacts.
Notes
Little Lake Wissota is a 400-acre eutrophic embayment of Lake Wissota, an impoundment of the
Chippewa River near Chippewa Falls, Wisconsin (Hydrologic Unit Code 07050005, Wisconsin
Waterbody Identification Code 2152800). The embayment has a maximum depth of 43 feet and a
drainage area of approximately 67 square miles. Paint Creek is the primary source of surface
water inflow to Little Lake Wissota.
The Little Lake Wissota watershed is located in the North Central Hardwood Forest Ecoregion
(Omernick and Gallant, 1988). This EPA Ecoregion is characterized by nearly level to rolling
glacial till plains, significant agricultural land use and lakes with phosphorus concentrations
greater than 50 ppb, indicative of eutrophic conditions. The lake was placed on the Wisconsin
303(d) impaired waters list in 1998 with a high priority ranking due to eutrophication and pH
criteria exceedances. In addition, recreational uses are limited during the summer due to poor
water quality from excess phosphorus (P) and sediment loading (Table 1). Land cover in the
watershed is primarily agricultural and forest (Table 2). The goal of this TMDL is to reduce
levels of phosphorus and sediment loading and decrease the extent and severity of summer algal
blooms in Little Lake Wissota. The TMDL was approved by US EPA in April, 2010.
Listing Details
Pollutant
Total Phosphorus
Listed For
Fish and Aquatic Life
Impairments
Eutrophication, Elevated pH
Current Use
Reservoir
Listing Status
TMDL Approved
Attainable Use
WWSF - Warmwater Sport Fishery
Priority
Not Applicable
Designated Use
WWSF - Warmwater Sport Fishery
303(d) ID
538
Listing Date
4/1/1998
Impaired Water Notes
Little Lake Wissota is highly eutrophic with excessive concentrations of phosphorus and
chlorophyll (a measure of algal densities) in its surface waters during the months of May through
September (USACE 2004, Brakke 1997). Sediment and phosphorus from nonpoint sources of
pollution enter the lake primarily from the Paint Creek watershed. Phosphorus is dissolved in the
water or bound to sediment particles, and once in the system, this phosphorus becomes available
to plants and algae. The lake’s relatively shallow depth, phosphorus-laden sediments and
excessive water column phosphorus levels, contribute to significant algal blooms during the
growing season (May - September). These eutrophic conditions impair recreational activities in
the lake. In addition, algal blooms in Little Lake Wissota are accompanied by pH exceedances.
The elevated lake pH levels are due to removal of carbon dioxide from water during
photosynthesis (by macrophytes and algae). This reduction in carbon dioxide levels during
daylight results in pH levels that frequently exceed the state criterion of 9.0. A reduction in
sediment and phosphorus loads to the lake would result in a decrease in chlorophyll levels and
reduction in maximum pH levels.
Date
9/17/2009

Impaired Water Notes
Little Lake Wissota (South Bay on Lake Wissota) Listed for pH, eutrophication (sediment and total phosphorus). TMDL submitted to USEPA for approval in 2010.
Date
2/17/2010

Impaired Water Notes
The TP and sediment TMDLs for Little Lake Wissota were approved by the USEPA April 13, 2010.
Date
4/13/2010

 
Pollutant
Sediment/Total Suspended Solids
Listed For
Fish and Aquatic Life
Impairments
Eutrophication
Current Use
Reservoir
Listing Status
TMDL Approved
Attainable Use
WWSF - Warmwater Sport Fishery
Priority
Not Applicable
Designated Use
WWSF - Warmwater Sport Fishery
303(d) ID
538
Listing Date
4/1/1998
Impaired Water Notes
Little Lake Wissota is highly eutrophic with excessive concentrations of phosphorus and
chlorophyll (a measure of algal densities) in its surface waters during the months of May through
September (USACE 2004, Brakke 1997). Sediment and phosphorus from nonpoint sources of
pollution enter the lake primarily from the Paint Creek watershed. Phosphorus is dissolved in the
water or bound to sediment particles, and once in the system, this phosphorus becomes available
to plants and algae. The lake’s relatively shallow depth, phosphorus-laden sediments and
excessive water column phosphorus levels, contribute to significant algal blooms during the
growing season (May - September). These eutrophic conditions impair recreational activities in
the lake. In addition, algal blooms in Little Lake Wissota are accompanied by pH exceedances.
The elevated lake pH levels are due to removal of carbon dioxide from water during
photosynthesis (by macrophytes and algae). This reduction in carbon dioxide levels during
daylight results in pH levels that frequently exceed the state criterion of 9.0. A reduction in
sediment and phosphorus loads to the lake would result in a decrease in chlorophyll levels and
reduction in maximum pH levels.
Date
9/17/2009

Impaired Water Notes
The TP and sediment TMDLs for Little Lake Wissota were approved by the USEPA April 13, 2010.
Date
4/13/2010