Why we need beavers

Environmental improvements to the landscape

By felling trees and making ponds, beavers create diverse micro-habitats, adding wetlands and deep pools. According to the OAEC report, fish, insects, birds and amphibians and river otters proliferate in beaver-influenced landscapes. Beaver dams slow down streams, reduce erosion, and allow water to sink into the ground. The ponds they make are deep, cool places where young fish, like coho salmon smolt, can survive through the summer.

Beaver increase diversity in plant life as well. Shallow parts of the beaver pond become wetlands and eventually meadows where unusual plant species can flourish. Beaver ponds and marshes help to filter out sediment and pollutants, making the downstream water cleaner. Wetlands support greater plant growth and also wet decomposition of plants which removes 5 to 40% of nitrogen pollution from stream water.

Beaver activity even sequesters carbon. Recent research shows that meadows and wetlands created by beavers capture more carbon than the grassland or forest that they replaced. One estimate by geologist Ellen Wohl is that a beaver meadow contains 10 to 30 times the carbon of a dry grassland, depending on its size and age.

See this kind of article is exactly the cowpusher we need to get reluctant farmers off the tracks and keep them from standing in the way of beaver success: detailed and scientific listings of their benefits, which is great at encouraging folks to think about beaver in a new way. I’m guessing that most of this article was based on the ‘Beaver in California” report from OAEC recently released. Because they got very minor details about general Vallejo right, and very obvious details about Martinez wrong.

Learning to live with the urban beaver

Beaver seem to be slowly moving back to the North Bay. A nonprofit in Martinez called Worth a Dam just held its 9th annual Beaver Festival, celebrating the more or less continuous occupation of a pond on Alhambra Creek since 2007. When beaver first moved into Alhambra Creek, in downtown Martinez, the city made plans to have them trapped and killed. A group of residents persuaded the city council to try an intervention that would keep the pond from flooding and it was successful. Beaver also appeared in downtown Napa in 2014 and are still there.

In Sonoma County there is only one verified beaver pond, on Sonoma Creek in Maxwell Farms Regional Park just outside the city of Sonoma. This is the second recent attempt by beavers to repopulate Sonoma Creek. According to an article in the Bohemian, a beaver family moved up Sonoma Creek to Glen Ellen in the 1990s, but was soon caught eating grapevines and exterminated. Left to themselves though, they will slowly re-populate our streams. Young beavers naturally disperse to find their own territory as adults and move from one watershed to another, either overland or by water.

Getting these techniques right involves understanding how a beaver thinks. When the City of Martinez ran an underwater pipe through the beaver dam to keep the pond below a certain level and prevent flooding, they made sure that the ingress and outlet of the pipe were both placed underwater since the sound of running water will prompt the beavers to build their dam higher. Also necessary is a change of human attitude, regarding beaver as environmental friends rather than enemies.

The funny thing is that this links to OUR description of the flow device and still manages to get the details wrong. The pipe goes over the dam and the outflow was above water in every condition but high tide. People over focus on the noise detail because they love the story about Michel LeClare discovering that beavers covered the tape recorder with mud. But in reality there are other essential things beavers respond to that we have no way of observing. Like feeling the suction created by a leak on their very sensitive vibrissa or guard hairs.

But really, you’re just being picky Heidi. These are minor details in some really good advertising for beavers. Thanks, Sonoma Wildlife!