Lake J.B. Thomas: 22.2% full as of 2023-12-09

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)
Today 2023-12-09 22.2 2,227.48 45,131 44,458 199,931 3,229
Yesterday 2023-12-08 22.3 2,227.50 45,196 44,523 199,931 3,230
2 days ago 2023-12-07 22.3 2,227.51 45,228 44,555 199,931 3,231
1 week ago 2023-12-02 22.4 2,227.57 45,422 44,749 199,931 3,236
1 month ago 2023-11-09 22.7 2,227.77 46,071 45,398 199,931 3,254
3 months ago 2023-09-09 18.7 2,225.19 37,980 37,307 199,931 3,006
6 months ago 2023-06-09 22.5 2,227.65 45,681 45,008 199,931 3,243
1 year ago 2022-12-09 24.9 2,229.08 50,417 49,744 199,931 3,386
*

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 2023-12-09 12:45 2,227.49 2,258.00 -30.51
1 hour prior 2023-12-09 11:45 2,227.49 2,258.00 -30.51
2 hours prior 2023-12-09 10:45 2,227.48 2,258.00 -30.52
6 hours prior 2023-12-09 06:45 2,227.49 2,258.00 -30.51
12 hours prior 2023-12-09 00:45 2,227.48 2,258.00 -30.52
24 hours prior 2023-12-08 12:45 2,227.51 2,258.00 -30.49
48 hours prior 2023-12-07 12:45 2,227.51 2,258.00 -30.49
*

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

Elevation-Area-Capacity Curves

1952-01-01 (source: USGS)
1999-11-01 (source: TWDB) : GIS Data
Data Source USGS:08118000

Lake Location