Lower Granite Dam Fish Ladder

At lower granite lock and dam s adult fish ladder longer duration elevated water temperatures began to form a thermal barrier to upstream migrating salmon and steelhead slowing and or stopping.

Lower granite dam fish ladder.

The adult salmonid trap is located adjacent to the adult fish ladder at lower granite dam on the south shore of the snake river. In portland district annual fish passage reports fishladder counts are combined to get the counts for each dam bonneville the dalles john day mcnary ice harbor and lower monumental each have 2 fishladders. When the adult trap is in operation a diversion gate is rotated across the fish ladder to route upstream migrating. 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.

The visitor center is open 8 30 am to 5 pm monday through saturday and has a fish ladder viewing point where you can see the fish go through the ladder under water. 12 toward pomeroy and look for signs to lower granite dam. Guided dam tours are available. The project provides hydroelectric.

Travel west on hwy. Lower granite dam this congressionally authorized project consists of lower granite dam navigation lock powerhouse a fish ladder and associated facilities. Jacks are not included in the count. You can view the fish ladder from outside.

Lower granite dam is the most upstream dam in the snake river system that has a fish ladder to allow adult salmon and steelhead to migrate upstream. Fish counts from each fishladder first 2 queries below go back to 1981. A complete description of the adult trap and its operation was reported by harmon 2003.