The on-going Yakima Phase II screen construction program is replacing obsolete Yakima basin fish screens constructed in the 1930s, 40s, 50?s, 60s, and 70?s. The new screens comply with current regional fish screen biological protection criteria adopted by the Columbia Basin Fish and Wildlife Authority (CBFWA) in 1995. The target objectives of the program are designed to meet three criteria which will: (1) reduce delay to a degree approaching zero; (2) reduce the possibility of injury or mortality to a degree approaching zero; and (3) allow fish to pass with little additional expenditure of energy. The new screens protect all species and life stages of anadromous and resident salmonids, including bull trout and steelhead which are now listed as ?threatened? under ESA.Old screens in the Yakima basin, and in other Columbia River subbasins, 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 hamper efforts to restore depressed salmonid populations through natural production or hatchery supplementation. Battelle Pacific Northwest National Laboratory (PNNL), under Project# 198506200, has evaluated and quantified survival and guidance rates at Phase II sites approaching 100% (ranging from 90 to 99%).The Phase II program directly addresses measure 7.11B.1 of the 1994 Columbia Basin Fish and Wildlife Program as amended in 1995. Phase II is consistent with the High Priority Projects listed in the 2000 CBFWA program and addresses RPA 149 of the National Marine Fisheries Service (NMFS) 2000 Biological Opinion on operations of the Federal Columbia River Power System (FCRPS). The Phase II program is outlined in the Yakima Subbasin Summary (Feb 2000). This funding proposal will allow completion of the few remaining Phase II diversion screens by the year 2004.
