Pacific Northwest
Elwha Dam during removal / Seattle Times environment reporter

Washington: Wood chips fly at Elwha River as beavers make a comeback

ELWHA RIVER — The Elwha watershed is booming with new life, after the world’s largest dam removal.

ELWHA RIVER, Clallam County — Beavers are back. It’s not hard to tell.

The signs are everywhere: felled trees and branches, with telltale tooth marks. Soft sedge meadows dimpled with belly tracks from beavers hustling to and fro. And in thickets of young alder and willow  — a 24/7 beaver cafe — multiple dams, built in a side channel of this reborn river.

The dams are subtle, just sticks pushed into a row, bank to bank, and a bit of mud. But the dams do the trick these genius eco-engineers are so good at, creating pools to ease their travels by swimming, rather than walking, to their favorite snack spot.

Created in the making of their dams, too, is a boost for salmon: These pools are perfect spots for juvenile salmon to rest and feed.



The intertwined lives of beaver and salmon emerging here is one more sign that the ecosystem-scale restoration of the Elwha, with the world’s largest-ever dam removal project, begun in 2011 and completed in 2014, is taking hold.

While salmon have always been the marquee species of this recovery, as the river from the mountains to the sea returns to a more natural state, all sorts of other animals also are benefiting, including beavers.

In 2010, the mouth of the Elwha was expected to change when the dams come out and more than 24 million cubic yards of sediment impounded behind the dams were unleashed.  (Anne Shaffer and CWI )
In 2010, the mouth of the Elwha was expected to change when the dams come out and more than 24 million cubic yards of sediment impounded behind the dams were unleashed. (Anne Shaffer and CWI )
Two dams were taken down on the Elwha River beginning in 2011 in the world’s largest dam-removal project. Over the next five years, the river unleased carried rocks, sand, silt, and even trees downstream, reshaping more than 13 miles of river and building a large delta in the Strait of Juan de Fuca. (Anne Shaffer and CWI )
Two dams were taken down on the Elwha River beginning in 2011 in the world’s largest dam-removal project. Over the next five years, the river unleased carried rocks, sand, silt, and even trees downstream, reshaping... (Anne Shaffer and CWI ) More

Two hydropower dams, Elwha and Glines Canyon, were built on the Elwha in the early 1900s to power Port Angeles and give industry a kick start on the Olympic Peninsula. But taking the dams down has given beavers a chance to build some dams of their own in the Elwha’s delta, a natural powerhouse of enterprise, thrumming with new life.

Millions of tons of sediment that had been stuck behind the dams have flowed to the nearshore, building what is today Washington’s newest beach. The Coastal Watershed Institute, a Port Angeles nonprofit, also has been working at removing armoring from the shoreline near the river mouth — more than 43 percent of all of the shoreline armoring removal in Puget Sound in 2015-2017. Thousands of linear feet of old asphalt, concrete and rock were hauled off the beach to once again let the saltwater meet the land.

Not just creatures of fresh water, beavers also have an important place in the newly emerging habitat at the mouth of the Elwha and its tidally influenced floodplain, and juicy marshes and swamps, bristling with native cattails and sedge.

Anne Shaffer, of the Coastal Watershed Institute, has with her team of partners been documenting conditions in the nearshore before and after dam removal. The pool that she has monitored at the delta with the most diversity and greatest number of fish is the one to which the side channel used by beavers connects, Shaffer said. “It’s a beneficial relationship,” she said.

And not only on the Elwha.

Greg Hood is a senior research scientist with the Skagit River System Cooperative in La Conner, which provides natural resource management services for the Swinomish and Sauk-Suiattle tribes. Hood has worked on the Skagit River delta since 2000 and 10 years ago he surprised even himself when out looking for a plant in the delta and instead, discovered a whole new understanding of beavers.

The return of beavers and their dams to the Elwha River signal a recovery of the ecosystem after the removal of the Elwha and Glines Canyon hydropower dams in 2014. (Courtesy of the Coastal Watershed Institute)

Thought to be only freshwater animals, Hood discovered beavers were using the tidal shrub zone. These wetlands were among the first to be diked, drained and filled nearly out of existence in Puget Sound country as the region developed. But a place that is just terrific habitat for tidal beavers. Not a new species, but rather beavers making their living in a place where people did not expect them.

“I was really surprised, what is going on here? Beavers in tidal marshes?” Hood said. His paper published in 2009 was a first of its kind to expose and explain something that had been hidden in plain sight because no one thought to look for it. “People had been looking for beaver where they expected to find them,” Hood said.

In the Skagit, just as in the Elwha, the beavers were making dams that created pools that nurtured salmon — and kept predators at bay. Herons that prey on baby salmon can’t navigate a landing in the pools. And the pools create a nurturing, food-rich environment for the fish.

He learned densities of young salmon were five times greater in the pools than areas of the estuary without them. What emerged from his work was a new understanding of a relationship between rivers, salmon and beavers that had been entirely forgotten, in a kind of “ecological amnesia” — his beautiful phrase.

But on the Skagit, and now on the Elwha, that memory is returning, sharp as beaver-chewed sticks.

Lynda V. Mapes:  206-464-2515 or lmapes@seattletimes.com;  on Twitter: @LyndaVMapes.  Lynda specializes in coverage of the environment, natural history, and Native American tribes.

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See also Elwha: Roaring back to life . . .