Pat Mayse Lake: 94.4% full as of 2025-10-07

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 2025-10-07 94.4 449.86 111,486 107,326 113,683 5,516
Yesterday 2025-10-06 94.5 449.87 111,542 107,382 113,683 5,517
2 days ago 2025-10-05 94.6 449.89 111,652 107,492 113,683 5,519
1 week ago 2025-09-30 94.8 449.95 111,983 107,823 113,683 5,525
1 month ago 2025-09-07 97.9 450.57 115,429 111,269 113,683 5,591
3 months ago 2025-07-07 100.0 451.85 122,675 113,683 113,683 - n.a. -
6 months ago 2025-04-07 100.0 454.72 139,564 113,683 113,683 - n.a. -
1 year ago 2024-10-07 91.1 449.17 107,724 103,564 113,683 5,358
*

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 2025-10-07 17:00 449.84 451.00 -1.16 below flood pool
1 hour prior 2025-10-07 16:00 449.82 451.00 -1.18 below flood pool
2 hours prior 2025-10-07 15:00 449.82 451.00 -1.18 below flood pool
6 hours prior 2025-10-07 11:00 449.85 451.00 -1.15 below flood pool
12 hours prior 2025-10-07 05:00 449.85 451.00 -1.15 below flood pool
24 hours prior 2025-10-06 17:00 449.87 451.00 -1.13 below flood pool
48 hours prior 2025-10-05 17:00 449.87 451.00 -1.13 below flood pool
*

Data is provisional and subject to revision.

Additional Information

Impoundment date 1967-01-01
Vertical datum NGVD29
Dead pool elevation 415.00 ft above NGVD29
Service spillway crest elevation 451.00 ft above NGVD29
Emergency spillway crest elevation 477.00 ft above NGVD29
Flood pool elevation 460.50 ft above NGVD29
Top of dam elevation 488.50 ft above NGVD29
Conservation pool elevation 451.00 ft above NGVD29
Data download (CSV) period of record, last one year, last 30 days

Elevation-Area-Capacity Curves

1967-01-01 (source: USGS)
2008-07-01 (source: TWDB) : GIS Data
Data Source USACE:MYST2

Lake Location