Lake J.B. Thomas: 38.2% full as of 2018-07-23

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 2018-07-23 38.2 2,236.06 77,096 76,423 199,931 4,253
Yesterday 2018-07-22 38.3 2,236.09 77,224 76,551 199,931 4,257
2 days ago 2018-07-21 38.4 2,236.12 77,352 76,679 199,931 4,260
1 week ago 2018-07-16 38.7 2,236.30 78,120 77,447 199,931 4,281
1 month ago 2018-06-23 39.9 2,236.86 80,535 79,862 199,931 4,346
3 months ago 2018-04-23 43.3 2,238.37 87,238 86,565 199,931 4,536
6 months ago 2018-01-23 47.5 2,240.19 95,705 95,032 199,931 4,772
1 year ago 2017-07-23 56.1 2,243.62 112,932 112,259 199,931 5,269
*

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 2018-07-23 07:45 2,236.05 2,258.0 -21.9 below flood pool
1 hour prior 2018-07-23 06:45 2,236.05 2,258.0 -21.9 below flood pool
2 hours prior 2018-07-23 05:45 2,236.05 2,258.0 -21.9 below flood pool
6 hours prior 2018-07-23 01:45 2,236.06 2,258.0 -21.9 below flood pool
12 hours prior 2018-07-22 19:45 2,236.08 2,258.0 -21.9 below flood pool
24 hours prior 2018-07-22 07:45 2,236.08 2,258.0 -21.9 below flood pool
48 hours prior 2018-07-21 07:45 2,236.12 2,258.0 -21.9 below flood pool
*

Data is provisional and subject to revision.

Additional Information

Impoundment date 1952-01-01
Vertical datum NGVD29
Gauge USGS:08118000
Dead pool elevation 2,200.0 ft above NGVD29
Service spillway crest elevation 2,258.0 ft above NGVD29
Emergency spillway crest elevation 2,264.0 ft above NGVD29
Emergency spillway crest elevation 2,267.0 ft above NGVD29
Maximum design elevation 2,275.0 ft above NGVD29
Top of dam elevation 2,280.0 ft above NGVD29
Conservation pool elevation 2,258.0 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