Cooper (Chapman) Lake: 61.3% full as of 2026-11-11
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 | 2026-11-11 | 61.3 | 433.80 | 194,360 | 158,585 | 258,723 | 14,150 |
| Yesterday | 2026-11-10 | 61.4 | 433.82 | 194,643 | 158,868 | 258,723 | 14,163 |
| 2 days ago | 2026-11-09 | 61.5 | 433.84 | 194,926 | 159,151 | 258,723 | 14,175 |
| 1 week ago | 2026-11-04 | 62.6 | 434.03 | 197,630 | 161,855 | 258,723 | 14,288 |
| 1 month ago | 2026-10-11 | 67.5 | 434.91 | 210,464 | 174,689 | 258,723 | 14,884 |
| 3 months ago | 2026-08-11 | 81.4 | 437.20 | 246,358 | 210,583 | 258,723 | 16,387 |
| 6 months ago | 2026-05-11 | 80.8 | 437.11 | 244,886 | 209,111 | 258,723 | 16,335 |
| 1 year ago | 2025-11-11 | 76.0 | 436.33 | 232,319 | 196,544 | 258,723 | 15,887 |
*
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 | 2026-11-11 08:00 | 433.79 | 440.00 | -6.21 |
| 1 hour prior | 2026-11-11 07:00 | 433.79 | 440.00 | -6.21 |
| 2 hours prior | 2026-11-11 06:00 | 433.80 | 440.00 | -6.20 |
| 6 hours prior | 2026-11-11 02:00 | 433.79 | 440.00 | -6.21 |
| 12 hours prior | 2026-11-10 20:00 | 433.80 | 440.00 | -6.20 |
| 24 hours prior | 2026-11-10 08:00 | 433.82 | 440.00 | -6.18 |
| 48 hours prior | 2026-11-09 08:00 | 433.84 | 440.00 | -6.16 |
*
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
