Download or read book A Summary of 22 Years of Fish Screen Evaluation in the Yakima River Basin, Summary Report 1985-2007 written by and published by . This book was released on 2007 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sixty fish screen facilities were constructed in the Yakima River basin between 1985 and 2006 as part of the Northwest Power and Conservation Council plan to mitigate the effects of federal hydroelectric projects on fish and wildlife populations. This report summarizes evaluations of some of those and other fish screen facilities conducted by Pacific Northwest National Laboratory (PNNL) from 1985 through 2006. The objective of these studies was to determine if the newly designed and constructed fish screens were effective at providing juvenile salmonids safe passage past irrigation diversions. To answer that question, PNNL conducted release-and-catch studies at eight Phase I sites in the Yakima River basin. Increasing concerns about the impacts of hatchery fish releases on the wild fish population, as well as the cost and time necessary to perform these kinds of biological studies at more than 60 planned Phase II sites, required development of techniques to evaluate the effectiveness of the sites without releasing fish. The new techniques involved collecting information on screen design, operation, and effectiveness at guiding fish safely through the fish screen facility. Performance measures including water velocities and passage conditions provide a good alternative to biological studies at significantly lower cost and time. Physical techniques were used at all 10 Phase I and 28 Phase II sites evaluated by PNNL over the following 19 years. Results of these studies indicate the Phase I and II fish screen facilities are designed and capable of providing safe passage for juvenile salmonids so long as construction, maintenance, and operations meet the criteria used in the design of each site and the National Marine Fisheries Service criteria for juvenile fish screen design.