In September 2019, WATER Institute Co-Directors Brock Dolman and Kate Lundquist attended the International Conference on Ecology and Transportation to present on the Bring Back the Beaver Campaign, specifically on their consulting with Caltrans (California Department of Transportation). The conference was a global convening of biologists working to mitigate the impacts of transportation on ecosystems worldwide. Kate and Brock’s innovative strategies were well received by ecologists and transportation specialists – their useful insights are transferable to other places in the world in managing different species who present similar conflicts due to culvert blockage.
About the Caltrans Project
Back in 2015 Caltrans (District 5, San Luis Obispo area) constructed a new roadway in Prunedale CA near a wetland inhabited by beaver who soon dammed up the culverts and began to cause flooding. The wetland was a critical habitat for Western pond turtles and the endangered Red-legged frog and so there was interest in mitigating the flooding while preserving the wetland.
Caltrans invited OAEC WATER Institute and Swift Water Design to advise District 5 staff about benefits of beaver to watersheds and how to utilize non-lethal management strategies. The three entities worked together to install a flow control device (see infographic below) at the Prunedale site.
The pond leveler/flow control device:
- maintains the level of the water at a desired height below the grade of the road, protecting the road bed
- discourages additional dam height, reducing the amount of beaver harvest & damage of mitigation tree plantings
- requires low-impact installation – can be done by two people in one day using only hand tools with no vehicles in the wetland channel
- keeps the beaver dam which continues to maintain valuable habitat for sensitive species
Years later, the device is still working with the desired effects and beaver continue to inhabit the area. The device continues to perform well even during heavy rain years. For a more in-depth explanation on how the pond leveler works and some humorous photos of the installation process at the Prunedale site, check out Swift Water Design.