American Falls Reservoir, ID

As of 2026-09-30, American Falls Reservoir sits at 4309.56 ft, which is about average for this time of year. Over the past 30 days the level has fallen 1.89 ft.

The most recent reading at American Falls Reservoir is 4309.56 ft (2026-09-30), sourced from the U.S. Bureau of Reclamation. Readings on this page refresh automatically as the agency publishes new data.

The highest level for American Falls Reservoir in our records is 4354.53 ft on 2024-05-24. The lowest is 4306.52 ft on 2025-10-01. Our record covers about 4 years of readings.

Compared with every September in our records, the current level is higher than 48% of them, which we classify as about average for this time of year. Seasonal comparison matters more than the raw number, because most reservoirs draw down predictably through late summer and refill over winter and spring.

Reservoir levels move for four main reasons: rainfall and runoff into the basin, releases through the dam for downstream water supply, power generation or flood control, evaporation during hot months, and seasonal drawdown schedules set by the operating agency. American Falls Reservoir has fallen 1.89 ft over the past 30 days. For the operational reason on any given week, check the U.S. Bureau of Reclamation directly.

American Falls Reservoir is +2.94 ft compared with this date last year (4309.56 ft today). The full-history chart above covers 4 years, with a record high of 4354.53 ft and a record low of 4306.52 ft.