Composed of loose particles of sand, clay, silt, and other substances, sediment can flow into bodies of water by way of runoff in both urban and rural areas.
Much of the sediment in MN waters comes from erosion of bluffs and streambanks, urban stormwater, and runoff from construction sites and plowed fields.
Much of the sediment in MN waters is contaminated by toxic substances like phosphorus. Sediment can also affect the turbidity of lakes and streams, and the clarity of water. The more cloudy water is, the less sunlight reaches aquatic plants. In addition, sediment in the water can also harm fish and other aquatic life by affecting their ability to breathe underwater, as well as their ability to develop eggs and larvae. One example of sediment negatively affecting Minnesota waters is Lake Pepin on the Mississippi River. Lake Pepin is a naturally occurring lake, that is 21 miles long and covers 29,295 acres of land. High levels of sediment carried in by rivers surrounding Lake Pepin contribute to the large quantity of sediment coming into the Lake. By taking action to reduce the amount of sediment coming into the lake, we can also reduce the amount of contaminants clinging to sediment, leading to reduced algal growth, and ensuring that the lake is fishable and swimmable.
Strategies for reducing turbidity focus on slowing the rate at which water runs off the land and allowing it to evaporate or soak into soils where possible. How?: Build soil health so it can retain more water reduce tillage (preparation of land for growing crops) to slow erosion and run off
Plant vegetative buffers on the edges of farm fields and next to bodies of water restore eroded bluffs and streambanks
Sediment | Minnesota Pollution Control Agency
Contaminated sediments | Minnesota Pollution Control Agency
Problem Overview — Lake Pepin Legacy Alliance