Education

What is a watershed?
All the area that drains to a single creek, stream, or river. Watersheds may be large or small, depending on the size of the stream and the topography of an area. Unlike municipal boundaries, watershed boundaries are defined by nature, and therefore watersheds often overlap a number of municipal, county, or state boundaries. The Cedar, the Iowa, the Wapsi, the Skunk, the Des Moines rivers are part of the Mississippi’s watershed. Approximately the eastern 2/3 of Iowa drains to the Mississippi.

What are the details of the Cedar River Watershed?
The Cedar River Watershed includes portions of 23 counties in Iowa and 4 counties in south-central Minnesota. The watershed drains 7,830 square miles of land. During the river’s 335 mile journey, it is fed by the sub-watersheds of the Little Cedar, the Winnebago, the Shell Rock, the West Fork Cedar, Beaver Creek, Wolf Creek, Prairie Creek and many other smaller streams. The Cedar River feeds into the Iowa river in Louisa County.

How is the land in the Cedar River Watershed used?
73% of the land is row crop land.
13% of the land is grassland or pasture.
5% of the land is developed, open space.
3% of the land is forest.
2% of the land is considered wetland.
2% of the land is sod or lawn.
1% of the land is developed/urban.
1% of the land is a water body.
Obviously, the 7,830 square miles of watershed area is dominated by row-crops.

How does the land-use impact the watershed?
Anything that changes the native vegetation of a watershed will have impacts, both positive and negative. By definition, farming changes the native vegetation. Row-crop farming exposes soils to wind and water. Livestock waste can run into streams. Towns and cities change native vegetation. Impermeable surfaces add to run-off. Waste from homes, streets, and businesses ends up in streams.

Streets, yards, businesses have many impermeable surfaces. Storm water is collected into storm sewers and runs directly into the river, carrying with it chemicals from lawns, trash from the streets, and sediment from construction sites or other bare ground. Farms drain to the river as well, by both surface and tile water, carrying with it valuable topsoil, fertilizers and pesticides, and often animal waste spread onto the ground or running off from feedlots. Neither is a wrong way to live—impact is inevitable. We all need to work to find ways to minimize the impact.