It's about dam time

 

Switches will be flipped today on the Elwha River, as generators at two notorious hydroelectric dams -- the Elwha and the Glines Canyon -- are turned off. It's a significant first-step in a process that will continue this summer, prepping the dams for their impending destruction.

The removal of the concrete giants, both of which are nearly a century old, has been debated and considered for years. They contribute only a small amount of power to the regional grid, and have contributed to the devastation of the river's once mighty salmon, steelhead, char and cutthroat trout runs (neither dam ever installed fish ladders or other passage devices). In 1992, Congress passed the Elwha River Ecosystem and Fisheries Restoration Act, which directed the Interior Department to complete a "full restoration of the Elwha River ecosystem" and its native sea-run fish. When the final environmental impact statement for the restoration was completed in 1996, it concluded that scrapping both dams was the only way to reach those goals. But funding was slow to catch up to the feds' noble ambitions. As we reported in 2001: "The restoration of the Elwha is a beacon of possibility for Western rivers. But its roller-coaster history is also a reminder that patience, tenacity and luck, as well as money, are needed to take down the dams."

Now, the pieces have finally fallen into place. This September, the first chunks of concrete will come out, kicking off the largest dam removal in U.S. history, and an equally colossal ecological experiment. "The dam removal on the Elwha is a science Olympics of sorts, a chance to watch natural processes in play as the river and its surroundings undergo ecological changes on a scale not seen before," reported the Seattle Times last year. How salmon will recolonize the river, and how the river will respond to a massive release of sediment from the dams' reservoirs, are among the project's great unknowns. 

Here's a quick by-the-numbers look at the historic project:

390,000 Number of salmon and other sea-run fish that annually returned to the Elwha to spawn before the dams went up

3,000 Number of salmon and other sea-run fish that annually spawn in the Elwha today

5 River miles sea-run fish have access to on the Elwha with the dams in place

70 Miles of habitat sea-run fish will have access to on the Elwha and its tributaries once the dams come down

~ 24 million Cubic yards of sediment sitting in the dams' reservoirs, "enough to fill a football stadium two miles high," according to the AP

400,000 Plants expected to be planted to restore habitat where the reservoirs were

$27 million Value of contract to remove the dams

3 Years it's expected to take to remove the dams

Cally Carswell is HCN's assistant editor

Photo courtesy National Park Service