North American Beavers!

Federal and state agencies, including in California, are considering beavers as conservation partners to restore habitat and bolster its resilience to climate change. Not only do the dams build up water reserves but a series of dams can act as speed bumps to slow flooding, and they can even sequester carbon.” Click on this link to watch a presentation (and following Q&A session) given by current, active ranchers to the Marin RCD board and partners on beavers and BDAs implemented in existing ranches. The presentation was given and supported by Jon Griggs with Maggie Creek Ranch, Betsy Stapleton with the Scott River Watershed Council, Tracy Schor with her family operation in Placer County, Occidental Arts and Ecology Center, and Marin RCD.

North American beaver (Castor canadensis) are what biologists call a “keystone species” as the habitat they create benefits many other species. Their dams improve water quantity and quality, increase late season flow and reduce the impacts of flooding. As well, Ben Godfarb states in a recent Water Deeply article, “The primary thing that beavers do is they slow down flows and they impound lots of water. Those slower flows in ponds and wetlands are really important for all kinds of reasons. The big one is water storage; they keep water on the landscape for longer, which makes it available not only to animals, but to human users as well. A lot of that water infiltrates into the ground, so [beavers] help to recharge aquifers. From a salmon standpoint, they’re unbelievably critical. Think about what it’s like to be a baby salmon – you’re this tiny little creature that gets eaten by bigger fish and birds and all kinds of things, and you’re looking for a nice, slow bit of slack water in which you can take refuge. You don’t want to be in the main channel because then you just get blown downstream. For a juvenile salmon or trout, you can’t really conceive of better habitat than a beaver pond or wetland.”

Despite these benefits, current California beaver policy solely focuses on recreational hunting and lethal nuisance management. In response, the WATER Institute has launched a Bring Back the Beaver Campaign to educate citizens about the importance of beaver. In order to improve water supply for humans and the environment and increase resilience to drought and climate change, we are working to integrate their management into California policy and regulation. As well, there is now cutting edge litigation taking place in Oregon over the killing of beavers in which may set a precedent by highlighting the important role that the animals play in ecosystem health. Read the full article by clicking HERE. To learn more, contact Kate Lundquist (ext. 118) or Brock Dolman (ext. 106) or check out THESE BEAVER RESOURCES.

In recent Beaver News (winter 2017-2018), the National Wildlife Federation (NWF) published a great article, Beavers as Ecopartners; These aquatic mammals are helping restore parched ecosystems in the West. In the article, NWF also included recently published research on BDAs (Beaver Dam Analogues) which are man-made, artificial beaver dams that serve the same purpose and reap the same benefits of beaver-made dams. The article, which can be fully enjoyed by clicking HERE, goes on to say, “[s]ince 2015, salmon and trout are thriving with the help of the new beaver ponds, which expand surface water, recharge groundwater reserves and improve water quality by filtering and trapping sediments and recycling nutrients. Their shaded, deep pools also provide cool refuge for fish and support a wide diversity of wildlife.

NOAA Fisheries biologist Michael Pollock is monitoring the region’s BDAs and found that they have raised water tables up to 3 feet as far as 1,500 feet from the dams. In addition, the BDAs have kept water flowing through fish-filled, downstream side channels all summer long, habitat that previously dried up during that time. Pollock says the positive impacts of the BDAs have reached far further than anticipated. “We didn’t expect that,” he says. Additional ponds can’t come too soon. Pollock’s survey of Sugar Creek last fall found 6,400 juvenile coho and steelhead in BDA ponds, which currently can provide habitat for only up to 6,800. If just a few hundred fish come back to spawn, they might run out of room. “It is a good problem to have,” says Pollock.

Any questions about urban streams management in Marin County? Want to inquire about beavers and beaver dam analoges? Contact Program Manager Sarah Phillips.

Beaver News


Chris Jordan and Emily Fairfax, Op-Ed: Want to fight climate change and drought at the same time? Bring back beavers, LA Times


As part of his presentation of the May Revision of the Fiscal Year 2022-23 state budget, Governor Gavin Newsom proposed a new Beaver Restoration program to be run by the California Department of Fish and Wildlife.

Strong Support for Proposed Beaver Restoration program at the California Department of Fish and Wildlife, letter from various environmental, sportfishing, agricultural, and government agencies


Effect of Beaver Dams on Water Surface Elevation and Water Quality –French Creek RKM 3.1 & RKM 2.9
Scott River Watershed Council


Ariel Rubissow Okamoto, Snorkel Surveys Reveal the Fish World of Mount Tam’s Creeks, Bay Nature


Steve Milne, Feds OK New Mercury Protections In California Waters, capradio


Zen Menahem, Ocean Acidification Makes Salmons Lose Ability To Sense Predators, According To Researchers From The University Of Washington, The Science Times

Effects of Ocean Acidification on Salmon and Sablefish Neurobehavioral Function – Evan Gallagher

Mark Prado, Kent Lake water flow study to look at fish impact, Marin Independent Journal

Barry Eberling, Follwing a wet winter, Napa River fish trap yields high salmon count, Napa Valley Register

Monica Heger, Dams Be Damned: California Rebuilds the Salmon Habitat It Destroyed, yes! Magazine


Wendy Culverwell, Learning to love the (Pacific) lamprey, Tri-City Herald

CalFish Lamprey Information


Kristin Hanes, California’s recent storms are devastating endangered salmon, SF Gate

The following is an update from Eric Ettlinger, Aquatic Ecologist with Marin Water on January 13, 2017: “The current state of affairs in Lagunitas Creek can be described as a glass-half-full/glass-half-empty situation. Or more accurately, a reservoir-full, streambed-empty situation. By the end of December the coho salmon run was on track to be larger than the parent generation of three years ago and continue the generational improvements we’ve seen for each of the last five years. But then came the unrelenting storms of the last two weeks. On the positive side those storms filled MMWD’s reservoirs and produced the high flows that can create and improve salmon habitats in Lagunitas Creek. On the negative side those flows destroyed many coho redds, washed away some of our salmon habitat structures, and severely hampered our survey work. We’ve heard rumors of fresh coho out there (and steelhead should be starting to spawn too), but we haven’t been able to see them ourselves. The most recent storm raised Lagunitas Creek flows to 4,300 cubic feet per second, which was the third-highest flow in 35 years. In the coming months we’ll see if this flood had significant impacts on incubating salmon eggs and/or last year’s fry. Previous major floods in 1998 and 2006 resulted in very poor egg survival, and we expect to see relatively few fry again this summer. One-year-old juvenile coho have survived recent large floods successfully, likely by seeking out slow water areas on floodplains.  Ironically, it may be moderate storm events that are most deadly, because flows stay confined in the stream channel and slow water habitats may be hard to find. This summer we’ll be enhancing a number of areas on Lagunitas Creek to provide exactly those kinds of slow water habitats. On an optimistic note, the floods this season have risen and receded rapidly, hopefully subjecting coho fry to fast, confined flows only briefly. In late March we’ll start counting the surviving smolts as they migrate to the ocean and, one way or the other, that data will contribute to our understanding of how salmon survive floods and what we can do to help.”