Ten years ago, on a river revered for its huge wild steelhead, more than a ton of dynamite reduced a 47-foot high dam to rubble. At the time, it was the largest dam ever removed in the United States. It was also the first dam to be removed without first removing entrained silt. The operation was a success in removing the silt within a few days and long term return of steelhead.
As with subsequent dam removal projects on rivers such as the Penobscot, Elwha and Carmel, it didn’t take long for migratory fishes such as salmon and steelhead to begin moving into the upper reaches of the Sandy River, habitat they hadn’t reached for more than a century.
But would taking out the dam lead to a real boost in anadromous fish numbers in the system? This October, in a 10-year retrospective, the Oregon Department of Fish and Wildlife looked at the numbers and offered the answer: an “unqualified yes.” The action was also revealing in that all of the silt was removed in days with the river returning to normalcy.