Lower Granite Dam Snake River

Directly below the confluence the river flows into lower granite lake formed by lower granite dam the uppermost dam of the lower snake river project.

Lower granite dam snake river.

River mile 107 5 constructed. Lower granite lock and dam was the fourth of four dams constructed as part of the lower snake river project authorized in the rivers and harbors act of 1945. On the lower snake river in southeastern washington it bridges whitman and garfield counties. Opened 45 years ago in 1975 the dam is located 22 miles 35 km south of colfax and 35 miles 56 km north of pomeroy.

Since 1975 adult salmon primarily chinook and steelhead have been trapped and sampled at lower granite dam on the snake river located in southeast washington. The lower granite dam which bridges garfield and whitman county was named for granite point located about six miles upstream toward clarkston from the dam. Army corps of engineers walla walla district normal operating pool 1. Lower granite lock and dam is a concrete gravity run of the river dam in the northwest united states.

Lower granite dam is 3 200 feet long making it the second longest dam of the four dams completed along the lower snake river between 1961 and 1975. Additional units 4 6 completed in 1978 owner. Corps of engineers fish reporting site dam date of count daily count total to date in 2020 total to date in 2019 5 year average total count to date bonneville oct 1 446 104 286 66 091 132 844 lower granite oct 1 1 623 28 838 12 500 33 485 counts include wild and hatchery origin fish. 746 5 feet powerhouse capacity.

Transport began in the late 1960 s as a research program on how to. 6 155 3 mw 932 mw total. 733 0 738 0 feet maximum pool 1. Preliminary construction started on the dam in july 1965 and proceeded smoothly in the early years.

2020 steelhead count from july 1 to december 31 2020 to view winter passage at bonneville dam go to. Lower granite dam was the final dam in the project. As the first collector dam on the snake river lower granite is a primary component of the juvenile fish transportation program. Paradoxically the combination of these factors gives the young salmon further time to grow and to feed in lower granite lake so when they begin the migration to the pacific ocean they often have a higher chance at survival compared to those salmon who migrate to the ocean earlier.