* Heron Lake Phosphorus Reduction Project


• Funded through a Clean Water Partnership loan program administered by the MPCA
• Timeframe: June 6, 2012 to May 23, 2016
• Loan funds: $320,031.73
• Inkind match (HLWD): $6,903.05
• Total project cost: $326,934.78

The Heron Lake watershed, a subwatershed of the West Fork Des Moines River (WFDMR) watershed, encompasses approximately 472 square miles and is located in portions of Nobles, Jackson, Murray, and Cottonwood Counties in southwestern Minnesota. In December 2008, the Environmental Protection Agency approved a Total Maximum Daily Load (TMDL) Report encompassing 32 impairments in the WFDMR watershed. These impairments include phosphorus, turbidity, and bacteria. The WFDMR and Heron Lake TMDL Study states the sources contributing to excess phosphorus in North and South Heron Lake were divided between point source, primarily wastewater treatment facilities and nonpoint sources, including cropland/pasture runoff and streambank erosion. The primary contributing sources to bacteria were found to be livestock on overgrazed ripairian pasture, surface-applied manure on cropland, feedlots lacking adequate runoff controls, and inadequate septic systems. To meet the water quality goals, a 10 percent to 86 percent reduction in bacteria, a 20 percent to 90 percent reduction in turbidity, and a 79 percent reduction in phosphorus is needed.

Decreasing the amount of phosphorus and bacteria entering the Heron Lakes is necessary to meet the TMDL goals. The Heron Lake Watershed District (HLWD) Watershed Management Plan, WFDMR and Heron Lake TMDL Implementation Plan, and county water plans recognize on-the-ground best management practices (BMPs) as being the most effective way to address these nutrients. 

From June of 2012 through May of 2016, HLWD staff worked with watershed landowners to achieve project implementation. During that time period 27 septic systems were replaced as shown in the map below. It is estimated that these replacements will reduce phosphorus by 277 pounds per year, nitrogen by 730 pounds per year, total suspended solids by 5,783 pounds per year, biochemical oxygen demand by 10,468 pounds per year, and bacterial colony forming units by 1.93 E+15.


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