Changes in water and land management are needed across the Minnesota River Basin to improve water quality in the state’s namesake river, as well as streams and lakes throughout the 10 million acres of the basin, according to four studies released today by the Minnesota Pollution Control Agency (MPCA) and local partners.
Learn more about the studies and overall goals for the watershed at an open house on Wednesday, July 31, from 4-7 p.m., at the Sibley Park Pavilion, 900 Park Lane, Mankato.
The studies, funded by the Legacy Amendment, determined the total maximum daily load (TMDL) or the maximum amount of a pollutant that a water body can accept and still meet water quality standards. The standards are designed to make sure waters are fishable and swimmable.
One study concerns the major portion of the Minnesota River, focusing on total suspended solids — sediment and other particles that cloud the water. The study calls for decreasing sediment in the river by 50%. The Minnesota River basin is a naturally vulnerable system with erodible soils, but some practices such as artificial drainage worsen the situation by bringing too much water at too fast a rate into the system.
Increasing flows are a major factor in the Minnesota River basin, accelerating erosion of river banks, reducing water quality, and threatening infrastructure. In the past 80 years, flows have doubled in the Minnesota River.
It isn’t just an increase in precipitation causing increased flow; the river actually carries more water now per inch of rain than historically. Increased artificial drainage, fewer wetlands to store water on the land, and lack of perennial vegetation all contribute to higher flows. The end result is erosion of fields and streambanks that send sediment into the water.
The muddy water then makes it hard for fish and other aquatic species to breathe, find food, and reproduce. The sediment is also filling in the Lower Minnesota River and even Lake Pepin downstream at a much faster rate than before European settlement — and intensive farming — of the basin.
"The Minnesota River is a historical, cultural, economic, and recreational asset for Minnesota,” says MPCA Commissioner Laura Bishop. “Improving the Minnesota River’s water quality does not start or end with one community or industry; rather it requires all of us to work together for the common good.”
In addition to the main Minnesota River, TMDL studies for the Lower Minnesota River, Minnesota River-Mankato, and Watonwan River watersheds will be open for comment. Together, these three studies look at dozens of river segments impaired by bacteria, sediment, nutrients, and/or chloride as well as 50 lakes with nutrient levels high enough to cause algae. The MPCA and partners have prepared watershed restoration and protection strategies (WRAPS) reports for the three watersheds, also open for comment.
“These studies are all pieces of the Minnesota River basin puzzle," Bishop says. "Now we need everyone in the basin to help put the pieces together. The good news is that many practices have multiple benefits. Enhancing soil health helps plant growth, can lead to better water quality, and even lessen the impact of climate change."
The Minnesota River flows 335 miles from Big Stone in South Dakota to the Mississippi River near St. Paul. Its basin includes all or parts of 37 counties, draining 17,000 square miles. It provides fishing and other recreation for much of southern Minnesota.
The TMDL for sediment covers nine major watersheds from the outlet of Lac qui Parle Lake in western Minnesota to the mouth of the Minnesota River. In all, 61 sections of the main river and its tributaries carry too much sediment to meet water quality standards. Most of it comes from bluff, ravine, and streambank erosion, driven by higher stream flows that result from field drainage and somewhat from increased precipitation.
The studies are part of the state’s program to monitor the health of Minnesota’s 80 major watersheds every 10 years. Last year, a TMDL for the Lower Minnesota recommended fixing feedlot and septic systems to reduce bacteria in the river.
To learn more about the studies:
- Visit the Minnesota River Basin portal on the MPCA website.
- Attend the July 31 open house, from 4-7 p.m., at the Sibley Park Pavilion in Mankato.
- Call or email Scott Maclean, MPCA watershed supervisor, 507-344-5250
To provide feedback:
- Submit comments in writing by 4:30 p.m., Friday, September. 20.
- Use the comment form on the comment page.
- Written comments must include a statement of your interest in the report and the action you wish the MPCA to take, including specific references to sections of the draft report you believe should be changed and the reasons for making those changes.