Fabricate and Install Yakima Basin Phase II Fish Sreens

Obsolete Yakima basin fish screens constructed in the 1930s, 40s, 50?s, 60s, and 70?s must be replaced or updated to comply with current regional fish screen biological protection criteria adopted by Columbia Basin Fish and Wildlife Authority (CBFWA), Fish Screening Oversight Committee (FSOC) in 1995. The project objective is to provide 100 percent protection from mortality and/or injury for all species and life stages of anadromous and resident salmonids, including bull trout and steelhead trout which are now listed as ?threatened? under ESA (6/98 and 3/99, respectively). Old screens in the Yakima basin, and in other Columbia River sub basins, may provide fair protection for large (4-6 inch long) yearling smolts, but provide poor protection for fry and fingerling life stages. Mortality of fry and fingerlings by irrigation diversions may reduce subsequent smolt production, and hampers efforts to restore depressed salmon and steelhead trout populations through natural production or hatchery supplementation. Biological evaluation of completed Yakima basin Phase II fish screen facilities by Battelle, Pacific Northwest National Laboratory (PNNL), under Project# 198506200, has quantified survival and guidance rates approaching 100% (ranging from 90 to 99%). Consequently, the state and federal fish agencies and Yakama Indian Nation (YIN) have proposed under Phase II to complete replacement or upgrade of all obsolete fish screen facilities in the Yakima basin by the end of FY 2003. No additional work under this project is anticipated after the final screen is installed in FY 2003.