Lake J.B. Thomas: 20.8% full as of 2026-11-03
Historical Data
| Date | Percent Full |
Mean Water Level (ft) |
Reservoir Storage (acre-ft) |
Conservation Storage (acre-ft) |
Conservation Capacity (acre-ft) |
Surface Area (acres) |
|
|---|---|---|---|---|---|---|---|
| Today | 2026-11-03 | 20.8 | 2,226.60 | 42,324 | 41,651 | 199,931 | 3,151 |
| Yesterday | 2026-11-02 | 20.8 | 2,226.60 | 42,324 | 41,651 | 199,931 | 3,151 |
| 2 days ago | 2026-11-01 | 20.7 | 2,226.54 | 42,135 | 41,462 | 199,931 | 3,145 |
| 1 week ago | 2026-10-27 | 20.4 | 2,226.33 | 41,477 | 40,804 | 199,931 | 3,126 |
| 1 month ago | 2026-10-03 | 19.7 | 2,225.89 | 40,111 | 39,438 | 199,931 | 3,082 |
| 3 months ago | 2026-08-03 | 23.5 | 2,228.28 | 47,742 | 47,069 | 199,931 | 3,302 |
| 6 months ago | 2026-05-03 | 26.1 | 2,229.78 | 52,815 | 52,142 | 199,931 | 3,466 |
| 1 year ago | 2025-11-03 | 32.6 | 2,233.33 | 65,916 | 65,243 | 199,931 | 3,920 |
*
Percent Full is based on Conservation Storage and Conservation Capacity and doesn't account for storage in flood pool.
**
Values above, including today's are averaged conditions. For near real-time instantaneous water level, see table below or the interactive map viewer.
Most Recent Instantaneous Water Level
| Date/time |
Water Level (ft) |
Conservation Pool Elevation (ft) |
Height Above Conservation Pool (ft) |
|
|---|---|---|---|---|
| Most recent | 2026-11-03 10:45 | 2,226.60 | 2,258.00 | -31.40 |
| 1 hour prior | 2026-11-03 09:45 | 2,226.59 | 2,258.00 | -31.41 |
| 2 hours prior | 2026-11-03 08:45 | 2,226.59 | 2,258.00 | -31.41 |
| 6 hours prior | 2026-11-03 04:45 | 2,226.60 | 2,258.00 | -31.40 |
| 12 hours prior | 2026-11-02 22:45 | 2,226.60 | 2,258.00 | -31.40 |
| 24 hours prior | 2026-11-02 10:45 | 2,226.59 | 2,258.00 | -31.41 |
| 48 hours prior | 2026-11-01 10:45 | 2,226.54 | 2,258.00 | -31.46 |
*
Data is provisional and subject to revision.
Additional Information
| Impoundment date | 1952-01-01 |
| Vertical datum | NGVD29 |
| Dead pool elevation | 2,200.00 ft above NGVD29 |
| Service spillway crest elevation | 2,258.00 ft above NGVD29 |
| Emergency spillway crest elevation | 2,264.00 ft above NGVD29 |
| Emergency spillway crest elevation | 2,267.00 ft above NGVD29 |
| Maximum design elevation | 2,275.00 ft above NGVD29 |
| Top of dam elevation | 2,280.00 ft above NGVD29 |
| Conservation pool elevation | 2,258.00 ft above NGVD29 |
| Data download (CSV) | period of record, last one year, last 30 days |
| Data Source | USGS:08118000 |
| USGS Monitoring Location | USGS:08118000 |
Lake Location
