Beavers Are Great for the Environment. As Neighbors, Not So Much

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WOODINVILLE, Wash. –- In this case, it’s not just the beavers that are eager.

The dam-building rodents are getting a boost across the West, thanks to their signature water-blocking homes that, it turns out, can have a positive effect on the local environment, and have gained the critters support from local tribes and wildlife biologists. Their dams hold back water flow in elevated regions, propping up groundwater supplies in areas hit by drought and reduced snowpack. They provide habitats for salmon. And while there are other, less natural ways to achieve the same effects, there’s one big advantage to beavers: They work for free.

A team led by Kent Woodruff, a U.S. Forest Service wildlife biologist, has spent eight years refining beaver relocation in Washington’s Methow Valley.

The goal: Make sure that the beavers being brought together are compatible. Think of it as a Match.com for beavers.

It’s not easy, setting up a beaver family. First Woodruff’s team has to determine each animal’s sex -– which is not immediately apparent from their genitalia. They paired the beavers off to see which couples had that special chemistry. Then, in some of the areas targeted for salmon restoration, they had to set up “starter homes” to get the beavers settled into their new neighborhood.

Since 2008, 240 beavers have been relocated to 51 sites in Washington.

The target areas are mostly public lands at higher elevations –- exactly the areas that supply much of the water for humans across the West. “We’re desperate for water storage,” said Woodruff, and “that’s easily enhanced by beavers.”

Fans include Washington’s Tulalip Tribe, which last year started its own relocation program in the Skykomish River Watershed with starter funding from the Environmental Protection Agency.

“We really learned from Kent’s group,” said Tulalip wildlife biologist Jason Schilling.

The Tulalips' short-term goal is to restore salmon runs on their ancestral fishing grounds and Schilling expects a couple dozen more relocations over the next five years. The cost so far has been around $200,000, he said.

But the tribe is also aware that the Skykomish basin is among those expected to see less snowpack due to warming –- and that beaver ponds can increase long-term storage and recharge groundwater.

“This year we’ve had just 30 percent of normal snowfall,” said Ben Dittbrenner, a University of Washington researcher helping with the Skykomish project. Warmer temperatures “changes that snow into rain and it flows straight down, there’s nothing holding that water.”

The new beaver dams, located in areas between 500 and 3,000 feet elevation, “hold that water as high up as possible” and then slowly release it throughout summer, said Dittbrenner, who also runs Beavers Northwest, a non-profit aimed at educating property owners and the public about beaver benefits.

“If we aren’t going to have as much snow as we used to,” he said, “we need to find another way to keep that water in the mountains until summer, and this looks like our best bet.”

Not only that, but “it’s really cost effective,” said Michael Pollock, an ecosystems analyst with the National Oceanic and Atmospheric Administration, citing a study that found that using beavers costs a fraction as much as conventional stream restoration.

Pollock himself oversees a beaver project in Oregon.

“Everything’s trending upward,” he said. His team helped “jumpstart” restoration by building more than 100 temporary dams for existing beavers that cost between $500-$1,000 each.

If there’s one downside to more beavers, it’s that sometimes they make messy neighbors.

Castor canadensis was nearly exterminated in the 1800s by trappers seeking their fur for hats and coats. But recovery means clashes with humans who don’t particularly like losing trees or having their property flooded when water backs up behind beaver dams.

“Beavers do amazing work, and how quickly they can change the landscape is quite remarkable,” said Brooke Jones, whose blueberry bushes and the only road to dozens of nearby homes were flooded for months last year by the beavers’ work in her town of Woodinville, outside Seattle. “It’s just unfortunate that this particular creek is in a very suburban area.”

But the beaver relocation programs run by Woodruff, the Tulalips and increasingly other groups across the West -- from California to Alaska -- show that even nuisance beavers can become helpful ones.

In Jones' case, the beaver family that caused the flooding was relocated by the Skykomish project.

The family was one of six relocated last fall. Three of the six families have stayed at the relocation sites and Schilling’s team hopes to attach GPS tags to a few more beavers this spring.

Back in suburban Woodinville, the next step for Jones and her neighbors is to install a “beaver deceiver” –- a pipe and fence system aimed at fooling beavers into thinking that stretch is not a good place to set up shop.

Whether those neighbors can find a happy balance with the beavers remains to be seen. “There’s usually not a lot of support for the beavers at our community meetings,” said Jonathan Morrison, president of the neighborhood association.

The area around the small local lake has other beavers as well, and Morrison said the challenge is to convince property owners that those are worth keeping since they help a significant salmon population in nearby Bear Creek. “We need to work harder to live with them,” he said, “because they’re a big part of the water system.”

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