Cottonwood River

Cottonwood River near New Ulm

The Cottonwood River is located in southwestern Minnesota in the counties of Brown, Cottonwood, Lyon, Murray, and Redwood. It begins near Balaton in southwest Lyon County and flows about 150 miles east to the Minnesota River near New Ulm. The watershed area is approximately 840,000 acres or 1,313 square miles.

The Cottonwood River watershed is one of the 13 major watersheds in the Minnesota River Basin. The entire Cottonwood River watershed has about 88% (739,000 acres) of the land in cultivation, 6% of the land in grassland, 1% is wetlands or water, and just under 3% is still wooded. The remainder of the land is farmsteads, gravel pits, rural development, and other land uses. Counties in the watershed include Lyon, Murray, Redwood, Cottonwood, and Brown.

The topography is that of a rolling upland area. Altitudes descend from west to east with the Coteau des Prairies serving as a watershed divide. Natural drainage patterns in the area were established by valleys formed from glacial meltwaters. End moraines, which were formed during the recession of the last glacier, are the most prominent features. There are 15 incorporated communities in this watershed, including Tracy, Sleepy Eye, Springfield, and New Ulm, and there are seven unincorporated communities.

What's being done

Monitoring and assessment

MPCA’s intensive watershed monitoring effort was conducted in 2017-2018 for the Cottonwood River Watershed. The Cottonwood River Watershed Project (CRWP) was awarded a Clean Water Partnership (CWP) Phase I Diagnostic Study grant by the MPCA in 1997 to begin an intensive study of land use and water quality in the Cottonwood River watershed. The CRWP was awarded a Phase II Implementation grant from the MPCA in 2000 to carry out the remediation strategies determined in the Phase I CWP.

Strategy development for restoration and protection

Following monitoring, a Watershed Restoration and Protection Strategy and an Implementation Plan is in development for the Cottonwood River Watershed. Technical assistance and best management practice cost-share programs are available for the Cottonwood River Watershed. TMDL assessments have been developed for the impaired waters located within the watershed boundaries.

Implementation plans

Subsequent grants were carried out to continue the implementation of best management practices (BMPs) outlined in the CRWP implementation plan as well as continued monitoring of surface waters in the watershed. Total Maximum Daily Load projects include a fecal coliform TMDL assessment in 2006-2009.