Upper Helemano Reservoir, HI

As of 2026-10-12, Upper Helemano Reservoir sits at 43.72 ft, which is above average for this time of year. Over the past 30 days the level has fallen 1.19 ft.

The most recent reading at Upper Helemano Reservoir is 43.72 ft (2026-10-12), sourced from the U.S. Geological Survey. Readings on this page refresh automatically as the agency publishes new data.

The highest level for Upper Helemano Reservoir in our records is 46.22 ft on 2013-01-28. The lowest is 25.19 ft on 2013-09-26. Our record covers about 15 years of readings.

Compared with every October in our records, the current level is higher than 78% of them, which we classify as 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. Upper Helemano Reservoir has fallen 1.19 ft over the past 30 days. For the operational reason on any given week, check the U.S. Geological Survey directly.

Upper Helemano Reservoir is +7.82 ft compared with this date last year (43.72 ft today). The full-history chart above covers 15 years, with a record high of 46.22 ft and a record low of 25.19 ft.