Lake J.B. Thomas: 22.4% full as of 2023-03-22

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 2023-03-22 22.4 2,227.58 45,455 44,782 199,931 3,237
Yesterday 2023-03-21 22.4 2,227.59 45,487 44,814 199,931 3,238
2 days ago 2023-03-20 22.4 2,227.59 45,487 44,814 199,931 3,238
1 week ago 2023-03-15 22.6 2,227.68 45,778 45,105 199,931 3,246
1 month ago 2023-02-22 23.0 2,227.97 46,723 46,050 199,931 3,272
3 months ago 2022-12-22 24.4 2,228.81 49,507 48,834 199,931 3,357
6 months ago 2022-09-22 27.5 2,230.59 55,661 54,988 199,931 3,563
1 year ago 2022-03-22 37.1 2,235.55 74,941 74,268 199,931 4,198
*

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 2023-03-22 15:45 2,227.59 2,258.00 -30.41
1 hour prior 2023-03-22 14:45 2,227.59 2,258.00 -30.41
2 hours prior 2023-03-22 13:45 2,227.58 2,258.00 -30.42
6 hours prior 2023-03-22 09:45 2,227.58 2,258.00 -30.42
12 hours prior 2023-03-22 03:45 2,227.58 2,258.00 -30.42
24 hours prior 2023-03-21 15:45 2,227.58 2,258.00 -30.42
48 hours prior 2023-03-20 15:45 2,227.61 2,258.00 -30.39
*

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