The Oregon Department of Fish and Wildlife (ODFW) has identified the need to improve fish passage at the Underhill Diversion on Fifteenmile Creek. Historically, a seasonal 4-foot stanchion dam has been installed and removed annually to support irrigation and stock water needs from April through November. An existing non-criteria fish ladder at this site has proven inadequate for juvenile steelhead, redband trout, and Pacific lamprey, particularly during periods of low flow and high water temperatures in late summer. prefabricated pool-and-weir style fishway that will be attached to the exterior of the existing concrete fish ladder. This new structure will provide improved passage conditions for target fish species during critical low-flow periods. Fabrication of the fishway is scheduled for winter 2025–2026, with installation planned for late summer 2026.
