Dam removal has proven to be the most effective intervention for restoring fish migration access, with dramatic welfare and population recovery benefits documented across multiple species.
Dams block fish from reaching spawning habitat they have used for thousands of years, creating population-level welfare failures as entire runs are blocked from reproductive success. Fish attempting to pass dams suffer from exhaustion and injury. Dam removal is increasingly recognized as cost-effective since many old dams have outlived their designed purpose and their removal benefits fisheries, flood control, and riparian ecology simultaneously.