The largest dam removal in history began today in Washington as construction crews took a 5000 pound jackhammer to the Glines Canyon Dam. Crews will start demolition on the Elwha Dam, which is five miles down river, on Saturday.
The Glines Canyon Dam, which was built in 1927 and stands 210 feet tall, will be taken apart concrete chunk after concrete chunk by a massive hydraulic hammer. The plan, according to the Seattle Times, is to remove about a foot and a half of the dam every day. The slow process will allow the sediment behind the dams to be gradually released.
Construction crews expect the removal of both dams to take about three years.
The Elwha Dam is even older than the Glines Canyon Dam. The Elwha Dam has been holding back the waters of the Elwha river since 1910. Congress passed the Elwha River Restoration act to restore the legendary fisheries of the Elwha River, but it has taken more nearly 20 years for the demolition to begin.
A press release from the Olympic National Park, reads:
“The Elwha River Restoration is an environmental and cultural restoration project which includes the nation’s largest dam removal and will free the Elwha River after nearly a century. Removing the 108-foot Elwha Dam and the 210-foot Glines Canyon Dam will allow anadromous fish to access more than 70 miles of protected habitat and help restore the river’s salmon populations from 3,000 to more than 300,000.”
On Saturday, a ceremony will be held to mark the removal of the Elwha Dam. Secretary of the Interior Ken Salazar will join Washington Governor Chris Gregoire, and a around 400 guests to watch the massive hammer take the first chunk out of the 100-year-old Elwha Dam.