Beavers and the Dams They Build Can Improve Water Quality

New study will look at water quality improvement from beaver dams

January 25, 2021, 10:27 am | Billy Beck

a beaver dam.AMES, Iowa – Depending on your perspective, beavers and the dams they build can be an intriguing phenomenon that creates wetland habitat, or a nuisance that leads to unwanted flooding and property damage.

A bit of a trouble maker, beavers do help improve ecosystems and they potentially play a key role in water quality improvement.

A new partnership between Iowa State University Extension and Outreach, the Department of Natural Resource Ecology and Management at Iowa State, and the Iowa Nutrient Research Center will study the water quality and quantity impacts of beaver dams in central Iowa, and how effective these dams are at reducing nitrogen and phosphorus concentrations in Midwest agricultural watersheds.

“Beaver dams have been studied heavily for fish and wildlife habitat, but there’s been limited research on how these dams impact nutrients and flooding in the Midwest,” said Billy Beck, assistant professor and extension forestry specialist at Iowa State University.

Beck is studying the nutrient reduction potential of dams in central Iowa, and results will be provided to the Iowa Nutrient Reduction Strategy science team. The data will be used to help clarify the influence within the stream channel and the processes associated with in-stream nutrient loss on watershed-scale nutrient loads.

Shelby Sterner, an Iowa State graduate student studying environmental science, is tasked with leading the study, which entails elements of forestry, hydrology, biogeochemistry and fluvial geomorphology (how water shapes the earth).

The overall goals of the project are to identify and quantify key nutrient removal processes associated with beaver dams in central Iowa, and estimate the potential impact of dams on watershed-scale nutrient loading within the agricultural Midwest.

Central Iowans who have beaver dams or a history of beaver activity on their property are encouraged to contact Beck to discuss the potential for water quality monitoring related to the study. He can be reached at 515-294-8837 or

Beck said he understands the frustration landowners often have with beaver dams. He’s not looking to promote them – per se – but he believes with some balance, they can be beneficial.

For additional information on this study, as well as other impactful INRC-funded efforts, visit the Projects Page and Water Quality Research Map, both found on the Iowa Nutrient Research Center wbsite.

Original photo: Standing near beaver dam. Caption: Everett Johnson (senior in animal ecology at Iowa State University) stands on the downstream side of an active beaver dam.

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