Beaver and restoration - the rest of the story


The June 8th HCN edition included an excellent article on the potential for beaver to restore western watersheds and, in the process, improve water supplies. The piece, however, omitted a few important caveats:

  • Before the occupation of the West by white folks, Beaver did not exist in all Western watersheds. This is reflected in the diaries and history of the mountain men. For example, Jedediah Smith scouted from Colorado to Southern California and then North to Oregon. He found some valleys loaded with beaver; but many of the watersheds he scouted – not only in the Southwest but even in Northern California and Oregon -contained no or only a scattering of beaver.
  • Many of the places beaver thrived are now fields of alfalfa or pastures for cattle. The Scott Valley where I lived for 40 years was once known as Beaver Valley. The first year Hudson Bay trappers worked it, they took out 50 mules loaded with beaver pelts. But there is no way the beaver are going to be restored in this valley; that would require moving out the people and the cattle. Beaver are still being killed in the Scott Valley as varmints today.
  • Even where beaver are natural and can be restored the water regime may not return to pre-white-settlement condition. That is because many of the slopes above the steams have been severely altered by humans. The West’s and likely the world’s largest reservoirs are its upland forest soils. Healthy forest soil generally is about 1/3 open space. It is these spaces which fill with water during the wet season and slowly release that water during the dry season. But humans have logged the majority of the West’s upland forests. Most of the logging has been done with big, heavy machines which compress the soil reducing or even eliminating the spaces where water is held and slowly released. Millions of miles of roads have been built to extract the timber and for other purposes and these too cause water to run off without the chance of storage by forest soil. Nobel laureate Wangari Maathai, when asked not too long ago why she chose to plant trees, replied that everyone knew that where there are trees there is also water. Here in the West that knowledge has been lost. We have been encouraged to ignore the critical role that forest soil plays in retaining water and releasing it slowly to streams. 

The movement to make a partnership with the Beaver People in order to restore western watersheds is welcome. But it is not a silver bullet that can solve the West’s thirst or restore our rivers. For that to take place we need not only beaver restoration but also the restoration of our upland forests and healthy forest soil. And in order for that to take place we will need to first overcome the still prevalent myth that logging can enhanced water supplies.

What we need are some pleistocene beaver
Jun 25, 2009 05:13 PM
Big as a volkswagon...

Sweeping generalizations don't pay, and I thank you for pointing this out. Indeed many rivers were historically beaver free, and the little buggers, admirable as they are for their diligence and hard work, can make restoration harder than it has to be.

I think the most important point you bring up is that the disturbance caused by man in the name of progress is really the culprit. Civil engineers, erosion control, a slavish devotion to surface flow as the answer to storm water control and the general disregard for soil is the reason we have so many water woes here in the west. Soil is a living thing, a reservoir of nutrients (water being the primary one) and a couple of careless hours of recreation or another damn road, maybe some culverts, a little flood control, and BLAM!! impaired watershed. Which then leads to more roads to service a Damn dam, or a new well and on and on.

Maybe what we need is some infrastructure decommision,

Can beavers chew through concrete? that would be a good start.
. . . and the beaver is connect to the . . .
Rob Edward
Rob Edward
Jul 02, 2009 04:55 PM
Excellent point, Felice. One other important thing to remember is that beaver rely on healthy riparian vegetation, and prior to European settlement, those conditions were provided in many places throughout the Northern Hemisphere by the hunting behaviors of wolves.

The restoration of wolves to Yellowstone has demonstrated just how integral the presence of wolves is to riparian health. Now, beaver are reclaiming parts of the Lamar Valley that they hadn't been seen in since the 1920s.