Columbia-Pacific Northwest Region

American Falls Concrete Spillway Rehabilitation Project

Water Operations

As of Dec. 1, 2022, American Falls Reservoir is 27% full. American Falls Reservoir will continue to fill over the winter and spring months ahead of irrigation deliveries in 2023. Current storage conditions in the upper Snake River storage system are below average.

American Falls Reservoir typically observes its peak reservoir levels April through June. As snowpack is depleted, natural flows in the watershed above American Falls recede, and deliveries of contractual storage from the reservoirs are made through the remainder of the irrigation season to supplement water supply; water also is stored in upstream reservoirs for the subsequent year’s water deliveries. On an annual basis, the lowest storage levels are observed in September, and the reservoir begins to refill in October.

During 2023, American Falls Dam and Reservoir will follow normal outflows and reservoir levels.

Reference
Upper Snake River Systems Water Operations >>