Stillhouse Hollow Lake water level today
On Oct 28, 2026, Stillhouse Hollow Lake is at 620.66 ft, 96.3% full (1.34 ft below full pool). That is 4.1 points above normal for this date.
Source: Texas Water Development Board · storage 221,309 of 229,796 acre-ft · provisional data
Stillhouse Hollow Lake percent full history
Percent full Normal range (10th–90th percentile, 1996–2025) Average
Stillhouse Hollow Lake from space
The same area near the lowest and the highest level since 2016, on clear days. Compare the shoreline and the coves.
Imagery: NASA GIBS, Harmonized Landsat Sentinel-2 (HLS). Landsat 8/9 courtesy of NASA/USGS; contains modified Copernicus Sentinel data 2023, 2026. Black specks are cloud and shadow masks.
Records and key dates
- Record high
- 100.0%Apr 27, 1990
- Record low
- 51.7%Sep 8, 1999
- 12-month high
- 100.0%May 2, 2026
- 12-month low
- 92.7%Apr 1, 2026
- Last time full
- Aug 13, 2026
- Change in 1 year
- −1.08 ft−3.0 pts
About Stillhouse Hollow Lake
- River basin
- Brazos
- Full pool (top of conservation pool)
- 622.00 ft
- Conservation capacity
- 229,796 acre-ft
- Surface area today
- 6,241 acres
- Dead pool elevation
- 515.00 ft
- Flood control reservoir
- Yes
- Water supply for
- Austin
- Data since
- Oct 1, 1988
Monthly average, last 10 years
Average percent full each month.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | 96% | 95% | 94% | 95% | 100% | 100% | 100% | 100% | 98% | 97% | — | — |
| 2025 | 93% | 92% | 91% | 89% | 91% | 95% | 99% | 100% | 100% | 99% | 98% | 97% |
| 2024 | 59% | 61% | 61% | 64% | 95% | 100% | 100% | 100% | 100% | 99% | 97% | 95% |
| 2023 | 72% | 71% | 70% | 69% | 69% | 68% | 65% | 61% | 58% | 58% | 61% | 59% |
| 2022 | 93% | 92% | 91% | 90% | 89% | 86% | 83% | 79% | 77% | 74% | 73% | 73% |
| 2021 | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 99% | 98% | 97% | 95% |
| 2020 | 91% | 91% | 93% | 99% | 100% | 100% | 98% | 94% | 99% | 100% | 100% | 100% |
| 2019 | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 99% | 98% | 95% | 93% | 92% |
| 2018 | 90% | 89% | 90% | 89% | 88% | 86% | 83% | 81% | 79% | 90% | 100% | 100% |
| 2017 | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 99% | 97% | 96% | 94% | 92% |
Frequently asked questions
Is Stillhouse Hollow Lake full?
Not quite. On Oct 28, 2026 Stillhouse Hollow Lake was 96.3% full, 1.34 feet below its full pool elevation of 622.00 ft. It was last full on Aug 13, 2026.
What is the normal level of Stillhouse Hollow Lake for this time of year?
Between 1996 and 2025, Stillhouse Hollow Lake averaged 92.2% full around Oct 28, and 8 in 10 years it was between 72.6% and 100.0%. Today it is +4.1 percentage points above that average.
What is the lowest Stillhouse Hollow Lake has been?
In the TWDB record, which starts in 1988, the lowest daily value was 51.7% on Sep 8, 1999. The highest was 100.0% on Apr 27, 1990.
How often is the Stillhouse Hollow Lake water level updated?
TWDB publishes one reading per day for each reservoir. We check for new data every 2 hours and show the date of the reading next to the level. Recent values are provisional.
What does percent full mean?
It is the water stored in the conservation pool divided by the conservation capacity (229,796 acre-feet for Stillhouse Hollow Lake). Water above the conservation pool is flood storage and is not counted, so a reservoir can show 100% while rising into its flood pool.