Lower Snake River Little Goose and Lower Granite Locks and Dams: Adult Fishway Systems Emergency Auxiliary Water Supply

The National Marine Fisheries Service NMFS, Endangered Species Act, Biological Opinion issued March 2, 1995, require the US Army Corps of Engineers to develop an emergency auxiliary water supply EAWS system for all adult fishways where determined to be necessary in coordination with NMFS A reconnaissance level technical report Lower Snake River, Adult Ladder Systems, Emergency Auxiliary Water Supply Phase I - Technical Report prepared in 1995, identified several alternative methods of providing emergency auxiliary water supply for each of the adult fishway systems at each of the four lower Snake River locks and dams to address the Biological Opinion requirement. This Emergency Auxiliary Water Supply, Phase II - Technical Report continues to evaluate the Phase I report alternatives for the Little Goose and Lower Granite Lock and Dams at a greater level of detail. The objectives of this Phase II report are to evaluate, in greater detail, the alternatives previously identified in Phase I report and recommend a selected alternative for providing EAW supplies for each of the adult fishway systems at Little Goose and Lower Granite. This Phase Ii report identifies a construction cost estimate, including engineering and design, supervision and administrative costs and presents a proposed schedule for completing the design and construction of the recommended alternatives for each dam.