Effects of Beaver Dams on Sediment Transport

Beaver dams and associated ponding affect sediment transport and trapping by pushing water onto the floodplain and decreasing stream velocity, allowing for increased sediment deposition.

For this part of the Tualatin beaver study, USGS assessed changes in sediment dynamics along beaver-affected reaches of Fanno Creek at Greenway Park and Bronson Creek. Here, we highlight results from the Fanno Creek reach. Fanno Creek is a high-energy urban stream with sufficient velocity and turbulence to erode and transport huge loads of sediment during storms.

Findings will be helpful for quantifying the effects of beaver dams and ponds on sediment dynamics in flashy urban streams that have the erosive power and capacity to carry large amounts of sediment during storm events.