Cooper (Chapman) Lake: 65.1% full as of 2026-10-22
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 | 2026-10-22 | 65.1 | 434.48 | 204,127 | 168,352 | 258,723 | 14,588 |
| Yesterday | 2026-10-21 | 65.2 | 434.50 | 204,419 | 168,644 | 258,723 | 14,601 |
| 2 days ago | 2026-10-20 | 65.3 | 434.52 | 204,711 | 168,936 | 258,723 | 14,615 |
| 1 week ago | 2026-10-15 | 66.9 | 434.80 | 208,831 | 173,056 | 258,723 | 14,808 |
| 1 month ago | 2026-09-22 | 70.2 | 435.37 | 217,385 | 181,610 | 258,723 | 15,214 |
| 3 months ago | 2026-07-22 | 86.6 | 438.01 | 259,821 | 224,046 | 258,723 | 16,853 |
| 6 months ago | 2026-04-22 | 79.2 | 436.85 | 240,658 | 204,883 | 258,723 | 16,186 |
| 1 year ago | 2025-10-22 | 79.8 | 436.94 | 242,117 | 206,342 | 258,723 | 16,238 |
*
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 | 2026-10-22 05:00 | 434.47 | 440.00 | -5.53 |
| 1 hour prior | 2026-10-22 04:00 | 434.48 | 440.00 | -5.52 |
| 2 hours prior | 2026-10-22 03:00 | 434.48 | 440.00 | -5.52 |
| 6 hours prior | 2026-10-21 23:00 | 434.49 | 440.00 | -5.51 |
| 12 hours prior | 2026-10-21 17:00 | 434.50 | 440.00 | -5.50 |
| 24 hours prior | 2026-10-21 05:00 | 434.51 | 440.00 | -5.49 |
| 48 hours prior | 2026-10-20 05:00 | 434.53 | 440.00 | -5.47 |
*
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
