Cooper (Chapman) Lake: 67.3% full as of 2026-10-13
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 | 2026-10-13 | 67.3 | 434.87 | 209,869 | 174,094 | 258,723 | 14,856 |
| Yesterday | 2026-10-12 | 67.5 | 434.90 | 210,315 | 174,540 | 258,723 | 14,877 |
| 2 days ago | 2026-10-11 | 67.7 | 434.94 | 210,910 | 175,135 | 258,723 | 14,903 |
| 1 week ago | 2026-10-06 | 68.7 | 435.12 | 213,604 | 177,829 | 258,723 | 15,033 |
| 1 month ago | 2026-09-13 | 72.5 | 435.76 | 223,374 | 187,599 | 258,723 | 15,493 |
| 3 months ago | 2026-07-13 | 88.0 | 438.22 | 263,373 | 227,598 | 258,723 | 16,974 |
| 6 months ago | 2026-04-13 | 79.3 | 436.87 | 240,982 | 205,207 | 258,723 | 16,197 |
| 1 year ago | 2025-10-13 | 81.7 | 437.25 | 247,178 | 211,403 | 258,723 | 16,416 |
*
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 | 2026-10-13 17:00 | 434.85 | 440.00 | -5.15 |
| 1 hour prior | 2026-10-13 16:00 | 434.85 | 440.00 | -5.15 |
| 2 hours prior | 2026-10-13 15:00 | 434.87 | 440.00 | -5.13 |
| 6 hours prior | 2026-10-13 11:00 | 434.88 | 440.00 | -5.12 |
| 12 hours prior | 2026-10-13 05:00 | 434.88 | 440.00 | -5.12 |
| 24 hours prior | 2026-10-12 17:00 | 434.90 | 440.00 | -5.10 |
| 48 hours prior | 2026-10-11 17:00 | 434.92 | 440.00 | -5.08 |
*
Data is provisional and subject to revision.
Additional Information
| Impoundment date | 1991-01-01 |
| Vertical datum | NGVD29 |
| Dead pool elevation | 415.50 ft above NGVD29 |
| Emergency spillway crest elevation | 446.20 ft above NGVD29 |
| Flood pool elevation | 446.20 ft above NGVD29 |
| Maximum design elevation | 459.50 ft above NGVD29 |
| Top of dam elevation | 464.50 ft above NGVD29 |
| Conservation pool elevation | 440.00 ft above NGVD29 |
| Data download (CSV) | period of record, last one year, last 30 days |
Elevation-Area-Capacity Curves
1991-01-01 (source: USGS)
2007-07-01 (source: TWDB)
: GIS Data
2022-07-01 (source: TWDB)
: GIS Data
|
|
| Data Source | USGS:07342495 |
| USGS Monitoring Location | USGS:07342495 |
Lake Location
