Stillhouse Hollow Lake: 100.0% full as of 2025-07-07

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)
Most recent 2025-07-07 100.0 623.48 239,555 229,796 229,796 - n.a. -
1 day prior 2025-07-06 100.0 622.95 236,055 229,796 229,796 - n.a. -
2 days prior 2025-07-05 97.4 621.06 223,902 223,816 229,796 6,294
1 week prior 2025-06-30 95.3 620.30 219,156 219,070 229,796 6,195
1 month prior 2025-06-07 94.2 619.87 216,505 216,419 229,796 6,140
3 months prior 2025-04-07 89.9 618.23 206,625 206,539 229,796 5,902
6 months prior 2025-01-07 93.3 619.54 214,486 214,400 229,796 6,096
1 year prior 2024-07-07 100.0 626.15 257,808 229,796 229,796 - n.a. -
*

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 2025-07-07 23:00 624.50 622.00 2.50 into flood pool
1 hour prior 2025-07-07 22:00 624.34 622.00 2.34 into flood pool
2 hours prior 2025-07-07 21:00 624.17 622.00 2.17 into flood pool
6 hours prior 2025-07-07 17:00 623.56 622.00 1.56 into flood pool
12 hours prior 2025-07-07 11:00 623.26 622.00 1.26 into flood pool
24 hours prior 2025-07-06 23:00 623.11 622.00 1.11 into flood pool
48 hours prior 2025-07-05 23:00 622.61 622.00 0.61 into flood pool
*

Data is provisional and subject to revision.

Additional Information

Impoundment date 1968-01-01
Vertical datum NGVD29
Dead pool elevation 515.00 ft above NGVD29
Emergency spillway crest elevation 666.00 ft above NGVD29
Flood pool elevation 666.00 ft above NGVD29
Maximum design elevation 693.20 ft above NGVD29
Top of dam elevation 698.00 ft above NGVD29
Conservation pool elevation 622.00 ft above NGVD29
Data download (CSV) period of record, last one year, last 30 days

Elevation-Area-Capacity Curves

1968-01-01 (source: USGS)
1995-05-01 (source: TWDB) : GIS Data
2005-05-01 (source: TWDB) : GIS Data
2015-12-01 (source: TWDB) : GIS Data
Data Source USGS:08104050

Lake Location