Lower Monumental Dam spills water to benefit juvenile salmon, July 12, 2022. This year, federal water managers will spill hundreds of thousands of gallons of water over spillways instead of through turbines during annual “spring spill” operations at U.S. Army Corps of Engineers’ dams on the lower Snake and Columbia rivers. The operations start April 3 on the lower Snake River and April 10 on the lower Columbia River. These actions are intended to decrease the time it takes juvenile salmon and steelhead to move through the system of dams to the Pacific Ocean as well as provide a non-turbine passage route past the dams.