Ninetynine Island Reservoir, SC

As of 2026-10-12, Ninetynine Island Reservoir sits at 102.65 ft, which is high for this time of year. Over the past 30 days the level has risen 3.36 ft.

The most recent reading at Ninetynine Island Reservoir is 102.65 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 Ninetynine Island Reservoir in our records is 107.51 ft on 2024-09-28. The lowest is 94.73 ft on 2017-11-02. Our record covers about 21 years of readings.

Compared with every October in our records, the current level is higher than 99% of them, which we classify as high 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. Ninetynine Island Reservoir has risen 3.36 ft over the past 30 days. For the operational reason on any given week, check the U.S. Geological Survey directly.

Ninetynine Island Reservoir is +3.30 ft compared with this date last year (102.65 ft today). The full-history chart above covers 21 years, with a record high of 107.51 ft and a record low of 94.73 ft.