Lake J.B. Thomas: 54.7% full as of 2017-08-19

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, while 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 2017-08-19 54.7 2,243.06 110,004 109,331 199,931 5,190
Yesterday 2017-08-18 54.7 2,243.07 110,056 109,383 199,931 5,191
2 days ago 2017-08-17 54.8 2,243.09 110,159 109,486 199,931 5,194
1 week ago 2017-08-12 54.9 2,243.14 110,419 109,746 199,931 5,201
1 month ago 2017-07-19 56.5 2,243.74 113,565 112,892 199,931 5,285
3 months ago 2017-05-19 59.3 2,244.78 119,138 118,465 199,931 5,432
6 months ago 2017-02-19 63.6 2,246.36 127,887 127,214 199,931 5,634
1 year ago 2016-08-19 63.7 2,246.38 127,999 127,326 199,931 5,636
*

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 2017-08-19 18:45 2,243.06 2,258.0 -14.9 below flood pool
1 hour prior 2017-08-19 17:45 2,243.06 2,258.0 -14.9 below flood pool
2 hours prior 2017-08-19 16:45 2,243.05 2,258.0 -14.9 below flood pool
6 hours prior 2017-08-19 12:45 2,243.06 2,258.0 -14.9 below flood pool
12 hours prior 2017-08-19 06:45 2,243.07 2,258.0 -14.9 below flood pool
24 hours prior 2017-08-18 18:45 2,243.08 2,258.0 -14.9 below flood pool
48 hours prior 2017-08-17 18:45 2,243.08 2,258.0 -14.9 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 2200.0 ft above NGVD29
Service spillway crest elevation 2258 ft above NGVD29
Conservation pool elevation 2258.0 ft above NGVD29
Emergency spillway crest elevation 2264.0 ft above NGVD29
Emergency spillway crest elevation 2267.0 ft above NGVD29
Maximum design elevation 2275 ft above NGVD29
Top of dam elevation 2280 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