NINETYNINE ISLAND Reservoir Water Level
South Carolina · updated daily from the U.S. Geological Survey
99.38 ft
NINETYNINE ISLAND Reservoir is below average for this time of year and falling (-1.67 ft in the last 7 days).
Change since yesterday: +0.03 ft
Reading as of 2026-08-14 · higher than 30% of August readings on record
Where NINETYNINE ISLAND Reservoir sits historically
Today's level compared with every reading in our 20.9-year record for this lake.
Since yesterday
+0.03 ft
7-day change
-1.67 ft
30-day change
-0.49 ft
1-year change
-1.06 ft
Last 30 days
Last 12 months
Full history (20.9 years)
NINETYNINE ISLAND Reservoir records and averages
| Current level | 99.38 ft |
|---|---|
| Record high | 107.51 ft (2024-09-28) |
| Record low | 94.73 ft (2017-11-02) |
| Average of all readings | 99.73 ft |
| Data span | 20.9 years (7,507 readings) |
Frequently asked questions
Is NINETYNINE ISLAND Reservoir full right now?
As of 2026-08-14, NINETYNINE ISLAND Reservoir sits at 99.38 ft, which is below average for this time of year.Over the past 30 days the level has fallen 0.49 ft.
What is the water level at NINETYNINE ISLAND Reservoir today?
The most recent reading is 99.38 ft (2026-08-14), sourced from the U.S. Geological Survey. Readings on this page refresh automatically as the agency publishes new data.
What is the highest NINETYNINE ISLAND Reservoir has ever been?
The highest level 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 20.9 years of readings.
Is NINETYNINE ISLAND Reservoir low for this time of year?
Compared with every August in our records, the current level is higher than 30% of them — below 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.
Why is NINETYNINE ISLAND Reservoir low right now?
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 fallen 0.49 ft over the past 30 days. For the operational reason on any given week, check the U.S. Geological Survey directly.
How much has NINETYNINE ISLAND Reservoir changed over the past year?
The level is -1.06 ft compared with this date last year (99.38 ft today). The full-history chart above covers 20.9 years, with a record high of 107.51 ft and a record low of 94.73 ft.
Nearby lakes in South Carolina
Source: the U.S. Geological Survey. Readings are provisional and subject to revision by the publishing agency. All South Carolina lake levels.