Elwha River Dams are Gone

For one hundred years, the Elwha Dam stood resolute on the Elwha River just outside Olympic National Park in Washington. On September 27, 2011, the largest dam deconstruction project in history began and 13 months later, the Elwha Dam was gone and the once constrained river began to flow once again.

Glines Dam was just eight miles upstream. Glines, completed in 1926, faced the same fate as the Elwha: Complete removal of the 210 foot high dam over a period of several years. Early this week, engineers nearly reached bedrock when targeted blasts crumbled most of Glines’ remaining 35 foot section. The river is now primed to return to its former glory.

The Elwha River begins in the heart of Olympic National Park and makes a relatively short 75 mile run to the sea at the Strait of Juan de Fuca. At one time, the river supported spawning runs of Chinook, coho, chum, pink and sockeye salmon along with steelhead, cutthroat and bull trout. The runs were huge, with over 400,000 fish in 10 distinct populations that had the river full of spawning fish all year long.

 Power was needed to run the paper mills in Port Angeles, though, and the local timber company bought the land surrounding the dam sites and commenced construction. Despite an 1890 Washington law requiring dams to incorporate fish ladders, the developer fudged and built a hatchery instead. Thehatchery was a failure and closed in 1922 but 35 miles of pristine mainstem and 40 miles of tributary spawning habitat had still been plugged like a cork in a bottle.

 The dams and the hydropower they generated ruled for 80 years and fueled economic growth of Port Angeles.  Electrical power demand grew to the point where both dams combined could only supply 38% of the power needed by a single paper mill.

The question was asked more and more frequently: is that much power worth the loss of the entire river ecosystem? After an intense political battle, the “Elwha River Ecosystem and Fisheries Restoration Act of 1992” authorized the Federal Government to purchase the dams and decommission both of them. The re-birth of a river began.

 While removing huge concrete plugs from a river might seem to be a daunting problem, it was really the 34 million cubic yards of sediments—enough to cover 11 square miles three feet deep—that had collected behind the dams that caused the greatest challenge. The dams had to be dismantled in stages so that the sediment didn’t all wash into the river system at once.

Salmon are already beginning to return to the Elwha. Normal sediment loads are finding their way to the Strait and rebuilding the delta and its once extensive clambeds and sandy beaches. Recovery is expected to take 20-30 years, but when it is done, the Elwha experiment may show that though costly, the removing dams and restoring ecosystems is possible. Then it simply becomes a matter of choices and will for the American Public.