The Mississippi River from Fort Snelling to Lake Pepin used to be clear enough to grow all kinds of water plants and fish. But in the last 100 years, it changed. Now, the state has completed a two-decade long analysis of where most of the sediment that clouds the water is coming from -- the Minnesota River.

Starting this week the public has a chance to weigh in on the the Minnesota Pollution Control Agency's analysis. It's a critical point in the long, long process to clean up the river under the guidance of the Federal Clean Water Act.Once this public comment period closes on April 27 the hard part starts. Each county, town and township in this great watershed will have to figure out how to do their part in reducing sediment run off.

To learn more you can attend an open house on the report March 29, from noon to 9 p.m., at the St. James Hotel in Red Wing.

Star Tribune photo

Nearly half of the state drains into lower part of the Mississippi, along with parts of South Dakota, Iowa and Wisconsin -- nearly 50,000 square miles in all. To get there, water flows through hundreds of miles of ditches, streams and rivers from northern Minnesota, the rich farmland of the southern part of the state and from the Twin Cities. The sediment that pours in as well, which is rapidly filling in Lake Pepin and killing plant and aquatic life, comes from all sorts of land uses.

But the vast majority comes from land that drain the vast corn and soybean fields in central and western Minnesota. Here is how much sediment must be reduced -- the proverbial pollution diet -- in order to restore the river to what it once was, according to the state's analysis, or Total Maximum Daily Load.

• 60 percent from the Minnesota River during high and very high flows; 50 percent during average and low flows

• 50 percent from the Cannon River

• 20 percent from the Upper Mississippi River

• 25 percent from urban runoff

• 20 percent from smaller rivers and streams in Minnesota and Wisconsin that flow directly into the river.

The deadline for comments, which must be in writing, is 4:30 p.m. on April 27. Submit them to Bob Finley, 12 Civic Center Dr., Ste. 2165, Mankato, MN 56001 (fax 507-389-5422, email robert.finley@state.mn.us). Finley can be reached by phone at 507-344-5247 or 800-657-3864.

Written comments must include a statement of your interest in the report; a statement of the action you wish the MPCA to take, including specific references to sections of the draft report you believe should be changed; and specific reasons for your position.