Dam! That’s Impressive. The HOW and WHY of Tolan Creek Beaver Dam Analogues

This July the Bitterroot Water Partnership worked with the Bitterroot National Forest and Two Wolf Foundation to install over 30 ‘beaver dam analogues’ at our 150-acre Tolan Creek Headwaters restoration site. Here’s more on the how and why of all these dam analogues.

Extreme fire and unusual floods destroyed hundreds of acres of wetland habitat. This headwaters was left suffocated in rock debris and dust.

Such degradation permanently altered many of the foundational features that keep this habitat a ‘wetland’. Instead of slowly meandering, water just rushes off the drying land in straight, jetting streams.

Since the area can no longer hold onto water, you’ll find miles of dust-dry streams. Without proper moisture, plant life declines, sending the habitat into an even drier state.

Staff and volunteers from Two Wolf Foundation installed 30 ‘beaver dam analogues’ (BDAs) that mimic the function of beaver dams – an integral feature that catalyzes wetland recovery.

The team of powerful human beavers spent hundreds of hours collecting woody debris and weaving it into wooden posts to create these natural structures.

See how water is pooled on the upstream side of the BDA?

These dams slow water, so the landscape has time to soak it up like a sponge. The dams also act as natural filters by catching sediment, or fine dust debris, preventing it from settling into downstream fish breeding areas and suffocating eggs and aquatic life.

Just minutes after completion, clean water trickles past this beaver dam analogue. By holding onto water for a slower release, we can keep more cool water in the Bitterroot across our hot, dry summer.

Thank you for your enduring commitment to funding and advocating for conservation of our Bitterroot waters.