Lake Alan Henry: 94.3% full as of 2025-08-20

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 2025-08-20 94.3 2,218.00 90,747 90,747 96,207 2,659
Yesterday 2025-08-19 94.4 2,218.01 90,774 90,774 96,207 2,660
2 days ago 2025-08-18 94.4 2,218.03 90,827 90,827 96,207 2,661
1 week ago 2025-08-13 94.9 2,218.20 91,281 91,281 96,207 2,673
1 month ago 2025-07-20 96.9 2,218.92 93,224 93,224 96,207 2,724
3 months ago 2025-05-20 95.7 2,218.51 92,113 92,113 96,207 2,695
6 months ago 2025-02-20 97.1 2,219.00 93,442 93,442 96,207 2,730
1 year ago 2024-08-20 94.4 2,218.01 90,774 90,774 96,207 2,660
*

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 2025-08-20 16:30 2,217.99 2,220.00 -2.01
1 hour prior 2025-08-20 15:30 2,217.99 2,220.00 -2.01
2 hours prior 2025-08-20 14:30 2,217.99 2,220.00 -2.01
6 hours prior 2025-08-20 10:30 2,217.99 2,220.00 -2.01
12 hours prior 2025-08-20 04:30 2,218.00 2,220.00 -2.00
24 hours prior 2025-08-19 16:30 2,218.01 2,220.00 -1.99
48 hours prior 2025-08-18 16:30 2,218.02 2,220.00 -1.98
*

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