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Marmot Dam Removal Underway!

Posted: 07/24/2007
by Thomas O'Keefe

Sandy, OR — Earlier today a blast of explosives cracked the concrete face of Marmot Dam, beginning its demolition and ushering in a new era for Oregon’s Sandy River Basin. The removal will improve salmon and wildlife habitat and public recreation.

The Marmot Dam demolition on the Sandy River will be the largest dam removal in the Pacific Northwest in 40 years and the largest ever in Oregon. It will be the first phase in Portland General Electric’s (PGE) $17 million Bull Run Hydroelectric Project “decommissioning” plan, developed in consensus with 23 diverse organizations including American Whitewater represented by Regional Coordinator Keith Jensen.

“This partnership is taking a great step toward restoring a breathtaking river for fish, wildlife and people,” said PGE CEO and President Peggy Fowler. “We celebrate the future of a watershed that will provide unimpeded salmon and steelhead passage from the slopes of Mt. Hood to the Pacific Ocean.”

Following the detonation, heavy equipment began taking apart the concrete structure. This demolition will take about two months and during this construction period. During that work, the river bypasses Marmot Dam, diverted by earthen coffer dams. Once removal of the dam is completed and the fall rains return the coffer dams will be washed away and paddlers will have an opportunity to enjoy a free-flowing river.

“Free-flowing rivers are great for so many reasons,” said Dave Slover, owner of Alder Creek Kayak & Canoe and another party to the agreement for removal. “For kayakers, the removal of Marmot Dam means additional water in the river through spring and summer. With the eventual removal of the Roslyn Lake diversion, we will now get boatable flows through the incredible Sandy Gorge into August. Just like fish, kayakers love fresh, cool water in their rivers.”

Located about 40 miles east of Portland, the structure was built in 1913 to power a trolley that carried city dwellers out to the countryside and was rebuilt in 1989 after a flood. At 22 megawatts, Bull Run is one of PGE’s smallest generating facilities, and its power has already been replaced with environmentally friendly wind power and other sources.

PGE announced that it would remove the Bull Run Hydroelectric Project in 1999 after the company determined that demolition would be more economical for its customers than maintaining the facility and upgrading it to modern environmental standards. In developing the plan for removal, PGE committed to a collaborative agreement, rejecting the expensive and exhaustive adversarial proceedings that characterize many major environmental decisions.

"What's good for fish is good for paddlers," notes Thomas O'Keefe, American Whitewater's Pacific Northwest Stewardship Director. "We are incredibly excited to see restoration in action and we appreciate PGE's commitment to a vision that recognizes the river as a public resource. The voices of all stakeholders were heard in this process and the outcome is great for fish, great for paddlers, and great for the river."


For more information and to follow the progress of the removal visit the Marmot Dam website. An illustration of key steps in the removal process is provided below.


To remove Marmot Dam a coffer dam is constructed to divert the river around the dam structure. The dam can then be removed.


Following removal of Marmot Dam, the temporary coffer dam will be naturally eroded as flows increase during the fall.


A restored Sandy River following removal of Marmot Dam.


Associated Projects

Sandy River Restoration (OR)
AW is working to protect the Sandy River Gorge and restore the river through removal of Marmot Dam in Oregon.

Associated Rivers

Bull Run OR