Phosphorus in lakes and nitrates in streams are a top concern in the Cannon River watershed, according to intensive water monitoring and assessment by the MPCA and Cannon River Watershed Partnership. Other concerns include bacteria in the water, soil and other particles clouding the water, and mercury levels in fish.High levels of nutrients that cause algal blooms are hurting aquatic life and recreation in many lakes in this southeast Minnesota watershed. Nitrate levels in four trout streams are high enough to violate the standard for coldwater streams (the same standard is used for drinking water). Nitrates are a concern because of karst areas in the watershed — where the bedrock is porous and pollutants can easily reach groundwater.
Few of the water bodies studied in the Cannon watershed fully meet the swimmable and fishable standards. The vast majority fail to meet standards all the time.“People have extensively changed the land in the watershed with farming, drainage, building towns and applying fertilizers, which have all taken a toll on lakes and streams. While much has already been done in the Cannon watershed, additional work is needed to restores its lakes and streams,” the report concludes.Bright spots in the watershed include five lakes that are fully supportive of water quality standards: Beaver, Dudley, Fish, Kelly, and Roemhildts. These lakes need protection strategies to maintain their high quality.The Cannon River Watershed Partnership is holding a series of meeting to gather input on developing the Watershed Restoration and Protection Strategies for the Cannon. See the details on the partnership’s website.For more information on the watershed’s intensive monitoring results, visit the MPCA website.Photo above: The Wolf-Cannon river confluence shows the problems of high sediment and nutrient levels.
