Lake Osakis Watershed - Excess Nutrients: TMDL Project

This project addresses excess nutrient impairments in three lakes: Lake Osakis, Smith Lake and Faille Lake. The MPCA and Sauk River Watershed District (SRWD) have been working cooperatively on the TMDL study.

Map and location

Lake Osakis watershed is located in the Sauk River watershed, which lies in the west-central portion of the Upper Mississippi Basin.

TMDL report and implementation plan

Following the Osakis Lake Area Excess Nutrient TMDL approved in 2013, there remained an additional impaired lake in the watershed. "Clifford Lake" was a small, shallow lake for which limited information existed on its physical characteristics. The lake is the receiving water for the city of Osakis Wastewater Treatment Facility (WWTF).

Given the limited amount of physical characteristic data available, the development of a TMDL for the lake was postponed until additional information could be obtained on depth and size. Further examination revealed that the water body was much shallower than previous data had indicated. The lake morphometry and characteristics were determined to describe a wetland rather than a shallow lake. Clifford Lake was delisted (removed from the state's 303d list) and defined as a wetland. Currently there are no numeric eutrophication standards for wetlands in Minnesota. Any previous references to Clifford Lake in the TMDL have been revised to Clifford Wetland.

Faille Lake formerly did not have the discharge of a WWTF in its allocations. The allocations and modeling were reassessed and are shown and described in the addendum found at the very end of the draft TMDL. A new allocation table was created, so there are an original table and a revised table (Tables 4.2 and 4.3) in the draft TMDL.

Contact

Anna Bosch, Watershed Project Manager
218-316-3929