Otter Tail River Watershed Restoration and Protection Strategy Report

The Otter Tail River Watershed (OTRW) encompasses approximately 1,952 square miles in west-central Minnesota, with the southwestern most portion of the watershed ending at the Minnesota/North Dakota border. The watershed extends across major portions of Otter Tail and Becker counties with smaller areas of the watershed within Wilkin, Clay, Clearwater, and Mahnomen counties. It contains the cities of Fergus Falls, Detroit Lakes, Breckenridge, Perham, Pelican Rapids, Frazee, and New York Mills, and smaller towns with populations under 1,000. In 2016, the Minnesota Pollution Control Agency (MPCA) began its intensive watershed monitoring (IWM) within the OTRW (MPCA 2019a, 2019b, DNR, and MPCA 2019). Biological data were collected from 26 of the 231 individually defined stream reaches in the watershed during the 2-year sampling period (2016-2017). Water chemistry samples were also collected from 12 stream reaches. Of the over 1,300 lakes within the OTRW, 233 were assessed to determine if they met aquatic life and/or aquatic recreation water quality standards. Water quality within the OTRW is generally very good, with a majority of streams and lakes supporting aquatic life and/or aquatic recreation. Of the stream reaches that were assessed, 68% met aquatic life use standards and 63% met aquatic recreation use standards. Lake water quality in the watershed is also excellent. Eighty-five percent of assessed lakes met aquatic life use standards and 91% of assessed lakes met aquatic recreation use standards (MPCA 2019a).