MONONA -- Silver Creek, a warm water creek winding through Clayton County, had a muddy outlook until a community-led effort helped clear things up.
The stream, a tributary of northeast Iowa’s Turkey River, was taking on almost 15,000 tons of sediment each year, all washing into the creek from the surrounding 18,000 acres of land that drain into it. The extra dirt and sediment, along with the nutrients that wash along with it, were causing problems for the fish and aquatic life in the stream, like insects, snails, mussels and crayfish.
Sediment in waterways can completely bury or fill in gaps around many stream habitat types, like rocks and gravel, that are important to survival for many types of aquatic life. Sediment can fill in spaces between rocks, making this important habitat less suitable for invertebrates and fish, which use the spaces for feeding, shelter, spawning and egg incubation.
In 2007, a DNR study - called a Stressor Identification process - noted the sediment as the cause of the stream’s issues, and helped launch a locally-led watershed improvement project. Farmers, landowners, residents and government agencies joined together to make changes on the land to reduce the amount of sediment reaching the creek.
Launched that same year under the leadership of the Clayton County Soil and Water Conservation District, the Silver Creek Watershed Project has since helped landowners install more than 238,000 feet of terraces, 35 acres of grassed waterways, 830 feet of streambank protection and filter strips along two miles of streambanks.
“The interest demonstrated by Silver Creek landowners and farm operators over the 14 years of the project has been outstanding,” says Eric Palas, project coordinator. Combined with other efforts, the practices have reduced the amount of sediment reaching Silver Creek by about 60 percent.
That decrease in sedimentation has led to improved biological monitoring scores, indicating an improved habitat for Silver Creek’s fish and other aquatic species. “The biological scores for the creek have more than doubled, which is vastly better than I thought possible when we did the stressor identification back in 2007,” says Jen Kurth, DNR watershed project monitoring coordinator.
The Silver Creek Watershed Project was funded and supported by the Iowa DNR through U.S. Environmental Protection Agency Clean Water Act section 319 grants, the Clean Water State Revolving Fund and local landowners and farmers. Other major project partners included the Clayton Soil and Water Conservation District, the U.S. Department of Agriculture’s Natural Resources Conservation Service and Farm Service Agency, and the Iowa Department of Agriculture and Land Stewardship.
To learn more about the Silver Creek success story, go to:
https://www.epa.gov/sites/production/files/2020-12/documents/ia_silver_creek_1944_508.pdf.
Or find more Iowa success stories on EPA's web pages at
https://www.epa.gov/nps/success-stories-about-restoring-water-bodies-impaired-nonpoint-source-pollution#ia by clicking on the Iowa map.