Potholes Reservoir and O'Sullivan Water Level

As of 2026-08-14, Potholes Reservoir and O'Sullivan sits at 1031.74 ft, which is above average for this time of year.Over the past 30 days the level has fallen 6.65 ft.

The most recent reading is 1031.74 ft (2026-08-14), sourced from the U.S. Bureau of Reclamation. Readings on this page refresh automatically as the agency publishes new data.

The highest level in our records is 1046.62 ft on 2026-05-17. The lowest is 1025.85 ft on 2025-09-03. Our record covers about 4.6 years of readings.

Compared with every August in our records, the current level is higher than 73% of them — above 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. Potholes Reservoir and O'Sullivan has fallen 6.65 ft over the past 30 days. For the operational reason on any given week, check the U.S. Bureau of Reclamation directly.

The level is +1.67 ft compared with this date last year (1031.74 ft today). The full-history chart above covers 4.6 years, with a record high of 1046.62 ft and a record low of 1025.85 ft.