recent changes

2013-06-19: The vertical datums of gauge, conservation pool and dead pool elevations for this lake have been adjusted to NAVD88+0.68ft.

Lake L. B. Johnson: 95.3% full as of 2017-02-22

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)
Most recent 2017-02-22 95.3 824.52 130,145 109,783 115,249 6,073
1 day prior 2017-02-21 95.5 824.56 130,389 110,027 115,249 6,083
2 days prior 2017-02-20 95.5 824.57 130,450 110,088 115,249 6,085
1 week prior 2017-02-15 95.7 824.61 130,693 110,331 115,249 6,095
1 month prior 2017-01-22 76.0 820.63 107,918 87,556 115,249 5,377
3 months prior 2016-11-22 95.5 824.56 130,389 110,027 115,249 6,083
6 months prior 2016-08-22 95.7 824.60 130,632 110,270 115,249 6,092
1 year prior 2016-02-22 - n.a. - - n.a. - - n.a. - - n.a. - - n.a. - - n.a. -
*

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 2017-02-23 03:15 824.51 825.4 -0.9 below flood pool
1 hour prior 2017-02-23 02:15 824.51 825.4 -0.9 below flood pool
2 hours prior 2017-02-23 01:15 824.51 825.4 -0.9 below flood pool
6 hours prior 2017-02-22 21:15 824.45 825.4 -0.9 below flood pool
12 hours prior 2017-02-22 15:15 824.52 825.4 -0.9 below flood pool
24 hours prior 2017-02-22 03:15 824.54 825.4 -0.9 below flood pool
48 hours prior 2017-02-21 03:15 824.60 825.4 -0.8 below flood pool
*

Data is provisional and subject to revision.

Additional Information

Impoundment date 1951-01-01
Vertical datum NAVD88 +0.68
Gauge LCRA:2958
Dead pool elevation 793.4 ft above NAVD88 +0.68
Service spillway crest elevation 796.68 ft above NAVD88
Conservation pool elevation 825.4 ft above NAVD88 +0.68
Top of flood gate elevation 826.68 ft above NAVD88
Emergency spillway crest elevation 825.68 ft above NAVD88
Top of dam elevation 838.68 ft above NAVD88
Data download (CSV) period of record, last one year, last 30 days

Elevation-Area-Capacity Curves

2007-05-01 (source: twdb) : GIS Data

Lake Location