The Contra Costa Steam Plant of the Pacific Gas and Electric Company, engineered and constructed by the Bechtel Corporation, was confronted with a need for large quantities of water from the San Joaquin River and at the same time a method for preserving the fish life present.

The Pacific Gas and Electric Company believed both natural resources, the fisheries and water, could be utilized without sacrifice of one or the other and assigned the development of a solution to the Bechtel Corporation.

The purpose of this report is to make available to the industry the details of the investigation, the information gathered, and the things learned from a research and experimental project lasting more than a year.

The monograph is divided into parts following a chronological order of events.

The one on "Historical Background" describes the locale, the fisheries of the area, the Contra Costa Steam Plant and its condenser cooling water system, the original design considerations given for fish preservation and the problem that developed with the plant in operation.

The next part deals entirely with fish rescue measures taken as an expediency, an attempt for a quick solution to the problem and a decision to embark on a long-range practical research program.

The research project is dealt with in the fourth part of this monograph and covers the major phases of the research work and a summary of the program.

Part V, "Application," describes the solution developed at Contra Costa and the proposed methods to be employed for fish preservation at the new Pittsburg Steam Plant of the Pacific Gas and Electric Company.