Reservoir record
Cooper (Chapman) Lake
Cooper (Chapman) Lake is 74.5% full, holding 192,751 acre feet against a conservation capacity of 258,723 acre feet.
Updated September 5th, 2026
Percent full74.5%
Storage192,751AF
Conservation capacity258,723AF
Change today-472AF
Across the record-17,832AF
Recorded range74.5% to 81.4%
Record26days
Daily movement
The line follows every verified reading held for this reservoir.
The readings
Daily movement appears only when the previous reading is from the prior calendar day.
| Date | Percent full | Storage | Daily movement |
|---|---|---|---|
| September 5th, 2026 | 74.5% | 192,751 AF | -472 AF |
| September 4th, 2026 | 74.7% | 193,223 AF | -472 AF |
| September 3rd, 2026 | 74.9% | 193,695 AF | -789 AF |
| September 2nd, 2026 | 75.2% | 194,484 AF | -791 AF |
| September 1st, 2026 | 75.5% | 195,275 AF | -793 AF |
| August 31st, 2026 | 75.8% | 196,068 AF | -635 AF |
| August 30th, 2026 | 76.0% | 196,703 AF | -636 AF |
| August 29th, 2026 | 76.3% | 197,339 AF | -797 AF |
| August 28th, 2026 | 76.6% | 198,136 AF | -638 AF |
| August 27th, 2026 | 76.8% | 198,774 AF | -1,119 AF |
| August 26th, 2026 | 77.3% | 199,893 AF | -481 AF |
| August 25th, 2026 | 77.5% | 200,374 AF | -1,123 AF |
| August 24th, 2026 | 77.9% | 201,497 AF | -160 AF |
| August 23rd, 2026 | 77.9% | 201,657 AF | -805 AF |
| August 22nd, 2026 | 78.2% | 202,462 AF | -805 AF |
| August 21st, 2026 | 78.6% | 203,267 AF | -808 AF |
| August 20th, 2026 | 78.9% | 204,075 AF | -808 AF |
| August 19th, 2026 | 79.2% | 204,883 AF | -648 AF |
| August 18th, 2026 | 79.4% | 205,531 AF | -811 AF |
| August 17th, 2026 | 79.8% | 206,342 AF | -488 AF |
| August 16th, 2026 | 79.9% | 206,830 AF | -650 AF |
| August 15th, 2026 | 80.2% | 207,480 AF | -978 AF |
| August 14th, 2026 | 80.6% | 208,458 AF | -816 AF |
| August 13th, 2026 | 80.9% | 209,274 AF | -818 AF |
| August 12th, 2026 | 81.2% | 210,092 AF | -491 AF |
| August 11th, 2026 | 81.4% | 210,583 AF | First reading |
Every reading is available in the open water record.