What is this project all about?
Removing the Elwha and Glines Canyon dams will free the Elwha River after nearly 100 years. Salmon populations will swell, from 3,000 to more than 300,000 as all five species of Pacific salmon return to more than 70 miles of river and stream.
The returning salmon and restored river will renew the culture of the Lower Elwha Klallam Tribe, who have lived along the river since time immemorial. Tribal members will have access to sacred sites now inundated by water, and cultural traditions can be reborn.
Elwha River Restoration creates a living laboratory where people can watch and learn what happens when salmon return to a still wild and protected ecosystem. The return of fish will benefit bears, eagles and other animals that have been deprived of a vital food source for nearly a century.
Just as the dams and their hydroelectric power played a vital role in the history and development of the state of Washington's Olympic Peninsula, removing them will create new opportunities for growth and regional vitality. Removing the dams will reestablish the river's natural flow of sediment from the mountains to the coast—rebuilding wetlands, beaches and the estuary at the river's mouth.
Why remove the dams?
The dams were built in the early 1900s and have provided hydroelectric power to a mill for most of that time. However, neither dam was built to include any method of fish passage: the loss of more than 70 miles of salmon spawning and rearing habitat led to a dramatic decrease in fish populations and wide-ranging effects on the entire Elwha Valley ecosystem.
In the early 1990s, extensive environmental review showed that dam removal was the only way to restore native anadromous fish stocks and the river's ecosystem.
How was the decision made?
Two Environmental Impact Statements were also released. The Final Programmatic EIS, released in June 1995, concluded that removal of both dams was the only way to achieve full restoration of the Elwha River ecosystem and fisheries. The Final Implementation EIS, released in November 1996, studied sediment management and concluded that sediment accumulated within the two reservoirs should be allowed to erode downstream naturally.
A detailed timeline of the process is also available.
How will the dams be removed?
The total cost of Elwha River Restoration is approximately $324.7 million, which includes purchase of the two dams and hydroelectric plants from their previous owner, construction of two water treatment plants and other facilities to protect water users, construction of flood protection facilities, a fish hatchery and a greenhouse to propagate native plants for revegetation.
Will any electricity be lost as a result of dam removal? Why get rid of dams that are making money and creating cheap energy?
How will dam removal affect wildlife?
What will happen to all the sediment once the dams are removed?
To allow for a gradual release of sediment, plans call for a lowering of the water level in Lake Mills prior to the start of dam removal in 2011. A drawdown experiment was conducted in 1994, in which the reservoir was drawn down 18 feet over the course of one week, then allowed to remain stable for one week. As the water level dropped, the river began to cut into the existing delta, creating a deep and narrow channel. A new delta began to form at the new, lowered lake level and the river channel moved laterally along the existing delta. The test indicated that the gradual lowering of the water level would allow for efficient erosion and movement of the delta sediment load downstream.
Based on those findings, the water level in Lake Mills will be lowered in 2011 in preparation for dam removal. After the dam removal period (approximately two-and-a-half to three years), the river will begin to restore itself to natural conditions. Sediment transport will return to natural levels, resulting in restored and rejuvenated habitats downstream from the dams.
Will dam removal affect area beaches?
Last updated: February 28, 2015