State of Washington Department of Game v. Federal Power Commission

Since 1893, the City of Tacoma, a municipal corporation in the State of Washington, has produced, transmitted, distributed and sold for use electric energy generated in its own steam electric and hydroelectric plants. On December 28, 1948, the City filed with the Federal Power Commission an application for a license to construct, operate, and maintain two dams (one designated as the Mossyrock, the other as the Mayfield) with appurtenant power facilities on a State of Washington river known as the Cowlitz. The Cowlitz River flows southerly into the Columbia River seaward of Portland, Oregon.

The Mossyrock Development is proposed to be located sixty-five miles upstream from the Cowlitz mouth and is to comprise a dam rising five hundred feet above bedrock which will intercept the river runoff and store the accumulated water in a natural reservoir twenty-one miles in length. The flow will be equated through the dam and through a hydroelectric power plant having an initial power potential of 225,000 kilowatts and an ultimate potential of 75,000 more kilowatts.

The proposed Mayfield Development is to be located thirteen and one-half miles downstream from Mossyrock and is to consist of…