Lake Alan Henry: 76.6% full as of 2026-07-26

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 2026-07-26 76.6 2,210.99 73,717 73,717 96,207 2,236
Yesterday 2026-07-25 76.7 2,211.03 73,806 73,806 96,207 2,238
2 days ago 2026-07-24 76.8 2,211.08 73,918 73,918 96,207 2,241
1 week ago 2026-07-19 77.2 2,211.23 74,255 74,255 96,207 2,249
1 month ago 2026-06-26 78.1 2,211.60 75,090 75,090 96,207 2,267
3 months ago 2026-04-26 81.6 2,213.08 78,501 78,501 96,207 2,342
6 months ago 2026-01-26 85.2 2,214.54 81,971 81,971 96,207 2,414
1 year ago 2025-07-26 96.3 2,218.72 92,680 92,680 96,207 2,710
*

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 2026-07-26 15:30 2,210.97 2,220.00 -9.03
1 hour prior 2026-07-26 14:30 2,210.98 2,220.00 -9.02
2 hours prior 2026-07-26 13:30 2,210.98 2,220.00 -9.02
6 hours prior 2026-07-26 09:30 2,210.98 2,220.00 -9.02
12 hours prior 2026-07-26 03:30 2,211.00 2,220.00 -9.00
24 hours prior 2026-07-25 15:30 2,211.03 2,220.00 -8.97
48 hours prior 2026-07-24 15:30 2,211.07 2,220.00 -8.93
*

Data is provisional and subject to revision.

Additional Information

Impoundment date 1994-01-01
Vertical datum NGVD29
Service spillway crest elevation 2,220.00 ft above NGVD29
Emergency spillway crest elevation 2,240.00 ft above NGVD29
Maximum design elevation 2,245.00 ft above NGVD29
Top of dam elevation 2,263.00 ft above NGVD29
Conservation pool elevation 2,220.00 ft above NGVD29
Data download (CSV) period of record, last one year, last 30 days

Elevation-Area-Capacity Curves

1993-10-01 (source: USGS)
2005-07-01 (source: TWDB) : GIS Data
2017-08-01 (source: TWDB) : GIS Data
Data Source USGS:08079700
USGS Monitoring Location USGS:08079700

Lake Location