The Root River’s unique topography, geology, and location make it an outstanding example of a river in need of extra consideration, according to the report recently posted by the Minnesota Pollution Control Agency: Root River Watershed Stressor Identification Report
Of all the rivers that drain to the Mississippi, the Root River in southeast Minnesota is distinct. It is one of the largest watersheds in the state — 1,670 square miles — and touches six Minnesota counties. The river system is famous for trout fishing.
The Root River starts as a drainage ditch in Mower County, then winds 81 miles from intensely farmed areas through more wooded, rolling terrain, and finally through towering bluffs before emptying into the Mississippi River south of La Crescent. Near Forestville State Park, the river literally disappears underground and resurfaces at the Mystery Cave near Preston.
The river flows through some of the most unique geology in the world — karst. Here, the erosive effects of water have sculpted thick layers of limestone over thousands of years. The landscape is characterized by abundant sinkholes, springs, caverns, and underground waterways. Karst is like the Swiss cheese of rock. As water flows through karst, it mixes above and below ground. This mixing means pollutants on land can easily reach groundwater used for drinking.
As part of a health checkup of watersheds across Minnesota, a team of experts identified conditions, many of them driven by land uses, stressing aquatic life in the Root River system:
- Low dissolved oxygen levels
- Water temperature higher than optimal
- Nitrate levels
- Total suspended solids (TSS) clouding the water
- Lack of physical habitat
- Connectivity issues, such as dams or culverts blocking migration of fish
Stressor identification also detects streams in healthy condition with the goal of protecting them. The Root watershed has several streams of exceptional quality and maintaining their condition should be a priority. Several streams are vulnerable to becoming impaired and also need protection to keep them healthy for aquatic life.
To improve water quality in the Root River watershed, the MPCA recommends:
- Making the following high priorities — Reducing sediment and nitrate levels, and restoring habitat. Focus on reducing sediment eroding from cattle pastures and streambanks. Restore habitat by increasing woody debris and shade along streams. Shading will also help reduce temperatures that are stressing fish and bugs.
- Collecting additional data on dissolved oxygen levels, water temperature, and connectivity on some streams.
See the full report and other information on the Root River Watershed webpage. This study and other watershed efforts are funded by the Clean Water, Land and Legacy Amendment.