Lake J.B. Thomas: 24.9% full as of 2022-12-09

The elevation-storage rating curve used to produce the storage hydrograph is made of two segments: (1) the segment up to the conservation pool top (below the red line) is based on measured data, and (2) the segment in the flood pool (above the red line) is an extrapolation from the first segment and shouldn't be relied upon for flood storage information.

Historical Data

Date Percent Full Mean Water Level
(ft)
Reservoir Storage
(acre-ft)
Conservation Storage
(acre-ft)
Conservation Capacity
(acre-ft)
Surface Area
(acres)
Most recent 2022-12-09 24.9 2,229.08 50,417 49,744 199,931 3,386
1 day prior 2022-12-08 24.9 2,229.09 50,451 49,778 199,931 3,387
2 days prior 2022-12-07 24.8 2,229.06 50,349 49,676 199,931 3,384
1 week prior 2022-12-02 25.0 2,229.16 50,688 50,015 199,931 3,395
1 month prior 2022-11-09 25.7 2,229.55 52,021 51,348 199,931 3,439
3 months prior 2022-09-09 28.1 2,230.94 56,915 56,242 199,931 3,606
6 months prior 2022-06-09 32.8 2,233.44 66,348 65,675 199,931 3,935
1 year prior 2021-12-09 40.9 2,237.28 82,371 81,698 199,931 4,396
*

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 2022-12-10 02:45 2,229.08 2,258.00 -28.92
1 hour prior 2022-12-10 01:45 2,229.08 2,258.00 -28.92
2 hours prior 2022-12-10 00:45 2,229.08 2,258.00 -28.92
6 hours prior 2022-12-09 20:45 2,229.08 2,258.00 -28.92
12 hours prior 2022-12-09 14:45 2,229.09 2,258.00 -28.91
24 hours prior 2022-12-09 02:45 2,229.08 2,258.00 -28.92
48 hours prior 2022-12-08 02:45 2,229.09 2,258.00 -28.91
*

Data is provisional and subject to revision.

Additional Information

Impoundment date 1952-01-01
Gauge USGS:08118000
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

Elevation-Area-Capacity Curves

1952-01-01 (source: USGS)
1999-11-01 (source: TWDB) : GIS Data

Lake Location