Can the extremes of drought and flood that we increasingly experience be mitigated to even things out (see “Water: Too Little, Too Much,” June 3, 2011)?
It seems that environmentalists, hydrologists and government agencies in the West have been working on mitigation measures for quite a while, and have discovered that often the best way is to work with nature instead of treating every problem as an engineering problem.
In Washington state the effects of Columbia River flooding are a big concern because when the river (or any river) moves very fast, it exercises destructive force downstream while failing to replenish groundwater tables along its course. From early in the millennium, officials in Washington looked at the possibility of building several new dams, at a cost of billions of dollars—and at a potential cost in water loss, because water evaporates from the big impoundments created by dams. And the evaporation factor will likely be worse as the climate warms.
Then along came a proposal to use an unsalaried but highly skilled, tireless work force to help solve the problem: beavers.
Beavers’ dam-building activities help restore wetlands. They create deep ponds that minimize evaporation, remain cool enough to serve as habitat for desirable fish species like salmon, and raise water tables. They restore small streams, including meanders, and actually contribute to flood control by diverting water from the main river channel. Their activity enriches soil and aids the growth of trees, expanding habitat for birds and many species of animals.
And the cost of relocating them to the places where they are needed—around $1,000 per beaver family—is exponentially less than the cost of building dams.
The Land Council in Washington is sponsoring a project called the Beaver Solution, whose participants are placing beaver families at strategic points along the Columbia watershed. The results may eliminate the need for dams.
In other states as well—Wyoming, New Mexico, Utah and Montana—beaver are being used in watershed restoration programs.
People in Martinez, California learned what beavers can do after a pair of the passionate chewers built a dam 30 feet wide in Alhambra Creek, felling willows and other decorative vegetation. But local residents got the City Council to put a pipe through the dam to prevent flooding and let the beavers stay. The creek grew into a rich wetland habitat that within three years was hosting river otter, steelhead trout and mink.
Beavers as climate change heroes in the drought-ravaged West? Why not? They’ve been riparian restorers for thousands of years.
