Turbine‐Intake Fish‐Diversion System

Abstract

The development of a fish‐diversion system to be used in the turbine intakes of the Wanapum and Priest Rapids developments on the Columbia River, in the state of Washington, is described. The system uses a passive‐bar screen, installed through the emergency gate well, to produce a flow pattern that deflects downstream‐migrating juvenile salmonids into the gate well for subsequent removal and bypass to below the dam. The system is based on laboratory model studies and field tests. The model studies provide data on the hydraulic performance of the system and result in an understanding of the hydraulic features of the technique, which can be a guide for future designs. The studies also serve as a guide to development of the structural design of the system. The design, field tested in 1986, 1987, and 1988, attains a fish‐guidance efficiency of about 68% with a minimal of descaling (removal of fish scales by abrasion).