The world's largest dam removal project is nearing completion on Elwha River on Washington state’s Olympic Peninsula, and now it's time to enter the next phase of work on one of the greatest salmon rivers in the nation: the restoration of an entire watershed ecosystem.
A fantastic piece from Yale e360 discusses the intensity of the project:
The demolition of these two dams has become an evolving scientific experiment, one that entails the restoration of an entire watershed, from salmon to alders to otters. The two dams had starved the lower reaches of the watershed of sediment, and the lakes that formed behind them were filled with unnaturally warm water. Lake Mills and Lake Aldwell also elevated water temperatures downstream, and marine nutrients failed to cycle into the ecosystem, affecting species throughout the food chain, from black bear, eagles, and osprey at the top, to frogs and flies.
The dams caused the near-extinction of native strains of salmon including chinook, pink, and chum. Given their position at the center of this ecosystem, even a modest return of these migratory fish is crucial to restoring the Elwha watershed. The other major challenge facing the National Park Service is the management of tens of millions of cubic yards of sediment that have built up behind the dams.
Politically, what is happening on the Elwha may alter the landscape for large-scale dam removals in the United States as debates continue over the Pacific Northwest’s heavily-dammed Columbia River basin and Oregon’s Klamath.
Read the full piece -- and it is well worth the read! -- over at Yale e360.