Lake J.B. Thomas: 25.1% full as of 2022-11-29

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 2022-11-29 25.1 2,229.23 50,926 50,253 199,931 3,403
Yesterday 2022-11-28 25.2 2,229.24 50,960 50,287 199,931 3,404
2 days ago 2022-11-27 25.2 2,229.25 50,994 50,321 199,931 3,405
1 week ago 2022-11-22 25.1 2,229.21 50,858 50,185 199,931 3,401
1 month ago 2022-10-29 26.1 2,229.77 52,780 52,107 199,931 3,464
3 months ago 2022-08-29 28.0 2,230.87 56,663 55,990 199,931 3,597
6 months ago 2022-05-29 33.1 2,233.58 66,900 66,227 199,931 3,954
1 year ago 2021-11-29 41.3 2,237.46 83,164 82,491 199,931 4,418
*

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 2022-11-29 16:45 2,229.26 2,258.00 -28.74
1 hour prior 2022-11-29 15:45 2,229.25 2,258.00 -28.75
2 hours prior 2022-11-29 14:45 2,229.26 2,258.00 -28.74
6 hours prior 2022-11-29 10:45 2,229.26 2,258.00 -28.74
12 hours prior 2022-11-29 04:45 2,229.23 2,258.00 -28.77
24 hours prior 2022-11-28 16:45 2,229.24 2,258.00 -28.76
48 hours prior 2022-11-27 16:45 2,229.25 2,258.00 -28.75
*

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