Washington State Department of Ecology

Condit Dam Removal Project

Condit Dam (photo source: http://en.wikipedia.org/wiki/Condit_Hydroelectric_Project)

Project Overview

The Condit Hydroelectric Project is located in south-central Washington on the White Salmon River in Klickitat and Skamania Counties (map). Condit dam is located 3.3 miles upstream from the confluence of the White Salmon and Columbia Rivers. Constructed between 1911 and 1913 by Northwestern Electric Company, the facility includes a concrete gravity dam, a powerhouse, a wood-stave pipe connecting the dam, a surge tank and two penstocks leading to the powerhouse, and a 1.7-mile project impoundment, and Northwestern Lake. PacifiCorp Electric Operations (PacifiCorp) acquired the project in 1947.

PacifiCorp Energy plans to begin removing the dam in October of 2010, contingent on obtaining necessary regulatory approvals. Ecology's environmental reviews are necessary for the agency to issue regulatory approvals associated with the project. In particular, before the dam may be removed, PacifiCorp must obtain a Section 401 Water Quality Certification from Ecology. The 401 certification under the federal Clean Water Act certifies that water quality standards and other water-protection regulations are met during dam removal and subsequent restoration. The 401 outlines the steps PacifiCorp must take to protect water quality during dam removal.

The Washington State Department of Ecology (Ecology) is releasing a State Environmental Policy Act (SEPA) Draft Second Supplemental Environmental Impact Statement (SEIS) for The Condit Dam Removal Project on the White Salmon River.

Ecology undertook this supplemental review to better understand the implications of releasing the sediments behind the dam during dam removal. Elevated levels of naturally occurring mercury were found in some of the sediments. Studies indicate, however, that the release of the material during dam removal would actually reduce risks from the mercury by making it less likely to accumulate in fish.

Ecology previously conducted an environmental review of the project comparing the effects of continued operation of the dam with dam removal.