Imaging Smolt Behavior on an Extended-Length Submerged Bar Screen and an Extended-Length Submerged Traveling Screen at The Dallas Dam in 1993.

Abstract : The U.S. Army Engineer District, Portland, commissioned the Environmental and Hydraulics Laboratories, U.S. Army Engineer Waterways Experiment Station (WES), to conduct a study to facilitate the design and operation of fish bypass systems. A comparison of impingement behavior of smolts on extended-length submerged traveling screens and bar screens using underwater video imaging was made at The Dalles Dam. Smolt bypass systems were video imaged using low-light sensitive underwater cameras. These cameras recorded smolt behavior to two porosities and three discharges. Screen design had a significant effect on a number of impingement behavior variables and the standard deviation of water approach angles. The general observation was that the smolts can detect and more successfully avoid the traveling screens, while they are less able to detect the bar screens and are more likely to be imaged on or contacted by the bar screens. The necessary monitoring equipment does not exist, but research and development of such systems is ongoing at WES as apart of this study.