The department’s decision follows a multi-year process to evaluate the environmental risks associated with removing the hydroelectric project on the White Salmon River, which borders Klickitat and Skamania counties. PacifiCorp is proposing, under a multiparty settlement agreement, to remove the dam, built in 1913, instead of renewing its Federal Energy Regulatory Commission (FERC) operating license. License renewal would require fish passage upgrades.

Before receiving FERC approval to remove the dam, PacifiCorp Energy needed to obtain certification from the Department of Ecology that water quality standards and other water-protection regulations are met during dam removal and subsequent habitat restoration. The certification, required under the federal Clean Water Act, outlines the steps PacifiCorp must take to protect water quality during dam removal and habitat restoration.

“The issuance of the 401 certification makes it possible to remove the dam and meet the objectives of the Clean Water Act to restore and maintain the nation’s waters” said Polly Zehm, deputy director for the Department of Ecology. “Removal of the dam will allow the river to return to its natural free-flowing state.”

With the removal of the dam and old cofferdams within the river bed, Lower Columbia River Chinook salmon will regain free and unrestricted access to about 14 miles of historic habitat, and steelhead will regain free and unrestricted access to about 33 miles.