Lake L. B. Johnson: 92.9% full as of 2024-07-24

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 2024-07-24 92.9 823.75 123,656 104,816 112,778 6,296
Yesterday 2024-07-23 97.0 824.48 128,286 109,446 112,778 6,383
2 days ago 2024-07-22 98.2 824.69 129,628 110,788 112,778 6,403
1 week ago 2024-07-17 98.1 824.67 129,500 110,660 112,778 6,401
1 month ago 2024-06-24 98.9 824.80 130,333 111,493 112,778 6,413
3 months ago 2024-04-24 98.5 824.73 129,885 111,045 112,778 6,406
6 months ago 2024-01-24 98.2 824.68 129,564 110,724 112,778 6,402
1 year ago 2023-07-24 98.9 824.80 130,333 111,493 112,778 6,413
*

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 2024-07-24 10:15 824.57 825.00 -0.43
1 hour prior 2024-07-24 09:15 824.59 825.00 -0.41
2 hours prior 2024-07-24 08:15 - n.a. - - n.a. - - n.a. -
6 hours prior 2024-07-24 04:15 - n.a. - - n.a. - - n.a. -
12 hours prior 2024-07-23 22:15 - n.a. - - n.a. - - n.a. -
24 hours prior 2024-07-23 10:15 - n.a. - - n.a. - - n.a. -
48 hours prior 2024-07-22 10:15 - n.a. - - n.a. - - n.a. -
*

Data is provisional and subject to revision.

Additional Information

Impoundment date 1951-01-01
Vertical datum NAVD88 +0.68
Dead pool elevation 793.40 ft above NAVD88 +0.68
Service spillway crest elevation 795.00 ft above NAVD88 +0.68
Top of flood gate elevation 826.00 ft above NAVD88 +0.68
Emergency spillway crest elevation 835.50 ft above NAVD88 +0.68
Top of dam elevation 838.50 ft above NAVD88 +0.68
Conservation pool elevation 825.00 ft above NAVD88 +0.68
Data download (CSV) period of record, last one year, last 30 days

Elevation-Area-Capacity Curves

2007-05-01 (source: TWDB) : GIS Data
2020-06-01 (source: TWDB) : GIS Data
Data Source LCRA:2958

Lake Location