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 is 95.9% full as of 2016-07-01

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.

Date Percent Full Mean Water Level
(ft)
Reservoir Storage
(acre-ft)
Conservation Storage
(acre-ft)
Conservation Capacity
(acre-ft)
Surface Area
(acres)
Today 2016-07-01 95.9 824.64 130,876 110,514 115,249 6,102
Yesterday 2016-06-30 95.7 824.61 130,693 110,331 115,249 6,095
2 days ago 2016-06-29 95.8 824.62 130,754 110,392 115,249 6,097
1 week ago 2016-06-24 96.5 824.76 131,610 111,248 115,249 6,133
1 month ago 2016-06-01 95.3 824.53 130,206 109,844 115,249 6,075
3 months ago 2016-04-01 95.8 824.63 130,815 110,453 115,249 6,100
6 months ago 2016-01-01 95.7 824.61 130,693 110,331 115,249 6,095
1 year ago 2015-07-01 96.3 824.72 131,365 111,003 115,249 6,123
*

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 2016-07-01 13:45 824.65 825.4 -0.8 below flood pool
1 hour prior 2016-07-01 12:45 824.67 825.4 -0.7 below flood pool
2 hours prior 2016-07-01 11:45 824.64 825.4 -0.8 below flood pool
6 hours prior 2016-07-01 07:45 824.65 825.4 -0.8 below flood pool
12 hours prior 2016-07-01 01:45 824.65 825.4 -0.8 below flood pool
24 hours prior 2016-06-30 13:45 824.64 825.4 -0.8 below flood pool
48 hours prior 2016-06-29 13:45 824.61 825.4 -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