Lake L. B. Johnson: 98.9% full as of 2026-08-17

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 2026-08-17 98.9 824.80 130,333 111,493 112,778 6,413
Yesterday 2026-08-16 98.9 824.80 130,333 111,493 112,778 6,413
2 days ago 2026-08-15 98.7 824.78 130,205 111,365 112,778 6,411
1 week ago 2026-08-10 98.2 824.69 129,628 110,788 112,778 6,403
1 month ago 2026-07-17 92.9 823.75 123,656 104,816 112,778 6,296
3 months ago 2026-05-17 98.3 824.71 129,757 110,917 112,778 6,405
6 months ago 2026-02-17 98.9 824.81 130,397 111,557 112,778 6,414
1 year ago 2025-08-17 98.6 824.75 130,013 111,173 112,778 6,408
*

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 2026-08-17 22:30 824.80 825.00 -0.20
1 hour prior 2026-08-17 21:30 824.83 825.00 -0.17
2 hours prior 2026-08-17 20:30 824.77 825.00 -0.23
6 hours prior 2026-08-17 16:30 824.81 825.00 -0.19
12 hours prior 2026-08-17 10:30 824.79 825.00 -0.21
24 hours prior 2026-08-16 22:30 824.81 825.00 -0.19
48 hours prior 2026-08-15 22:30 824.82 825.00 -0.18
*

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