Lake Alan Henry: 82.0% full as of 2026-04-18

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)
Most recent 2026-04-18 82.0 2,213.23 78,853 78,853 96,207 2,349
1 day prior 2026-04-17 82.1 2,213.30 79,017 79,017 96,207 2,352
2 days prior 2026-04-16 82.2 2,213.32 79,064 79,064 96,207 2,353
1 week prior 2026-04-11 82.4 2,213.40 79,253 79,253 96,207 2,357
1 month prior 2026-03-18 83.2 2,213.75 80,081 80,081 96,207 2,374
3 months prior 2026-01-18 85.4 2,214.61 82,141 82,141 96,207 2,419
6 months prior 2025-10-18 90.6 2,216.62 87,146 87,146 96,207 2,561
1 year prior 2025-04-18 94.2 2,217.95 90,615 90,615 96,207 2,655
*

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 2026-04-18 23:30 2,213.22 2,220.00 -6.78
1 hour prior 2026-04-18 22:30 2,213.21 2,220.00 -6.79
2 hours prior 2026-04-18 21:30 2,213.21 2,220.00 -6.79
6 hours prior 2026-04-18 17:30 2,213.21 2,220.00 -6.79
12 hours prior 2026-04-18 11:30 2,213.21 2,220.00 -6.79
24 hours prior 2026-04-17 23:30 2,213.28 2,220.00 -6.72
48 hours prior 2026-04-16 23:30 2,213.31 2,220.00 -6.69
*

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

Lake Location