Lake L. B. Johnson: 98.3% full as of 2026-08-13

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 2026-08-13 98.3 824.71 129,757 110,917 112,778 6,405
Yesterday 2026-08-12 98.2 824.68 129,564 110,724 112,778 6,402
2 days ago 2026-08-11 98.1 824.66 129,436 110,596 112,778 6,400
1 week ago 2026-08-06 98.7 824.77 130,141 111,301 112,778 6,410
1 month ago 2026-07-13 98.5 824.73 129,885 111,045 112,778 6,406
3 months ago 2026-05-13 99.1 824.84 130,590 111,750 112,778 6,417
6 months ago 2026-02-13 98.3 824.70 129,693 110,853 112,778 6,404
1 year ago 2025-08-13 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 2026-08-13 07:00 824.73 825.00 -0.27
1 hour prior 2026-08-13 06:00 824.72 825.00 -0.28
2 hours prior 2026-08-13 05:00 824.68 825.00 -0.32
6 hours prior 2026-08-13 01:00 824.74 825.00 -0.26
12 hours prior 2026-08-12 19:00 824.70 825.00 -0.30
24 hours prior 2026-08-12 07:00 824.68 825.00 -0.32
48 hours prior 2026-08-11 07:00 824.66 825.00 -0.34
*

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
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