Texas AI Docket
Texas Water Watch

Reservoir record

Cooper (Chapman) Lake

Cooper (Chapman) Lake is 65.3% full, holding 169,082 acre feet against a conservation capacity of 258,723 acre feet.

Updated October 20th, 2026

Percent full65.3%
Storage169,082AF
Conservation capacity258,723AF
Change today-586AF
Across the record-41,501AF
Recorded range65.3% to 81.4%
Record71days

Daily movement

The line follows every verified reading held for this reservoir.

62.5%73.4%84.3% August 11th, 2026, 81.4% fullAugust 12th, 2026, 81.2% fullAugust 13th, 2026, 80.9% fullAugust 14th, 2026, 80.6% fullAugust 15th, 2026, 80.2% fullAugust 16th, 2026, 79.9% fullAugust 17th, 2026, 79.8% fullAugust 18th, 2026, 79.4% fullAugust 19th, 2026, 79.2% fullAugust 20th, 2026, 78.9% fullAugust 21st, 2026, 78.6% fullAugust 22nd, 2026, 78.2% fullAugust 23rd, 2026, 77.9% fullAugust 24th, 2026, 77.9% fullAugust 25th, 2026, 77.5% fullAugust 26th, 2026, 77.3% fullAugust 27th, 2026, 76.8% fullAugust 28th, 2026, 76.6% fullAugust 29th, 2026, 76.3% fullAugust 30th, 2026, 76.0% fullAugust 31st, 2026, 75.8% fullSeptember 1st, 2026, 75.5% fullSeptember 2nd, 2026, 75.2% fullSeptember 3rd, 2026, 74.9% fullSeptember 4th, 2026, 74.7% fullSeptember 5th, 2026, 74.5% fullSeptember 6th, 2026, 74.3% fullSeptember 7th, 2026, 74.0% fullSeptember 8th, 2026, 73.7% fullSeptember 9th, 2026, 73.5% fullSeptember 10th, 2026, 73.2% fullSeptember 11th, 2026, 73.0% fullSeptember 12th, 2026, 72.9% fullSeptember 13th, 2026, 72.6% fullSeptember 14th, 2026, 72.4% fullSeptember 15th, 2026, 72.1% fullSeptember 16th, 2026, 71.8% fullSeptember 17th, 2026, 71.5% fullSeptember 18th, 2026, 71.3% fullSeptember 19th, 2026, 71.0% fullSeptember 20th, 2026, 70.7% fullSeptember 21st, 2026, 70.4% fullSeptember 22nd, 2026, 70.2% fullSeptember 23rd, 2026, 69.9% fullSeptember 24th, 2026, 69.6% fullSeptember 25th, 2026, 69.4% fullSeptember 26th, 2026, 69.1% fullSeptember 27th, 2026, 68.8% fullSeptember 28th, 2026, 68.6% fullSeptember 29th, 2026, 68.4% fullSeptember 30th, 2026, 68.1% fullOctober 1st, 2026, 67.9% fullOctober 2nd, 2026, 68.7% fullOctober 3rd, 2026, 68.6% fullOctober 4th, 2026, 69.1% fullOctober 5th, 2026, 69.0% fullOctober 6th, 2026, 68.8% fullOctober 7th, 2026, 68.6% fullOctober 8th, 2026, 68.3% fullOctober 9th, 2026, 68.2% fullOctober 10th, 2026, 67.9% fullOctober 11th, 2026, 67.8% fullOctober 12th, 2026, 67.5% fullOctober 13th, 2026, 67.3% fullOctober 14th, 2026, 67.1% fullOctober 15th, 2026, 67.0% fullOctober 16th, 2026, 66.7% fullOctober 17th, 2026, 66.2% fullOctober 18th, 2026, 65.9% fullOctober 19th, 2026, 65.6% fullOctober 20th, 2026, 65.3% fullAug 11thSep 15thOct 20th
Daily percent full. The vertical scale follows this record's own range instead of starting at zero, so its movement stays visible without changing the measurement.

The readings

Daily movement appears only when the previous reading is from the prior calendar day.

DatePercent fullStorageDaily movement
October 20th, 202665.3%169,082 AF-586 AF
October 19th, 202665.6%169,668 AF-733 AF
October 18th, 202665.9%170,401 AF-882 AF
October 17th, 202666.2%171,283 AF-1,329 AF
October 16th, 202666.7%172,612 AF-592 AF
October 15th, 202667.0%173,204 AF-444 AF
October 14th, 202667.1%173,648 AF-446 AF
October 13th, 202667.3%174,094 AF-595 AF
October 12th, 202667.5%174,689 AF-595 AF
October 11th, 202667.8%175,284 AF-448 AF
October 10th, 202667.9%175,732 AF-598 AF
October 9th, 202668.2%176,330 AF-449 AF
October 8th, 202668.3%176,779 AF-599 AF
October 7th, 202668.6%177,378 AF-601 AF
October 6th, 202668.8%177,979 AF-452 AF
October 5th, 202669.0%178,431 AF-301 AF
October 4th, 202669.1%178,732 AF+1,354 AF
October 3rd, 202668.6%177,378 AF-451 AF
October 2nd, 202668.7%177,829 AF+2,097 AF
October 1st, 202667.9%175,732 AF-448 AF
September 30th, 202668.1%176,180 AF-748 AF
September 29th, 202668.4%176,928 AF-601 AF
September 28th, 202668.6%177,529 AF-601 AF
September 27th, 202668.8%178,130 AF-753 AF
September 26th, 202669.1%178,883 AF-604 AF
September 25th, 202669.4%179,487 AF-605 AF
September 24th, 202669.6%180,092 AF-758 AF
September 23rd, 202669.9%180,850 AF-912 AF
September 22nd, 202670.2%181,762 AF-305 AF
September 21st, 202670.4%182,067 AF-915 AF
September 20th, 202670.7%182,982 AF-765 AF
September 19th, 202671.0%183,747 AF-614 AF
September 18th, 202671.3%184,361 AF-768 AF
September 17th, 202671.5%185,129 AF-616 AF
September 16th, 202671.8%185,745 AF-771 AF
September 15th, 202672.1%186,516 AF-773 AF
September 14th, 202672.4%187,289 AF-620 AF
September 13th, 202672.6%187,909 AF-621 AF
September 12th, 202672.9%188,530 AF-311 AF
September 11th, 202673.0%188,841 AF-623 AF
September 10th, 202673.2%189,464 AF-623 AF
September 9th, 202673.5%190,087 AF-625 AF
September 8th, 202673.7%190,712 AF-783 AF
September 7th, 202674.0%191,495 AF-627 AF
September 6th, 202674.3%192,122 AF-629 AF
September 5th, 202674.5%192,751 AF-472 AF
September 4th, 202674.7%193,223 AF-472 AF
September 3rd, 202674.9%193,695 AF-789 AF
September 2nd, 202675.2%194,484 AF-791 AF
September 1st, 202675.5%195,275 AF-793 AF
August 31st, 202675.8%196,068 AF-635 AF
August 30th, 202676.0%196,703 AF-636 AF
August 29th, 202676.3%197,339 AF-797 AF
August 28th, 202676.6%198,136 AF-638 AF
August 27th, 202676.8%198,774 AF-1,119 AF
August 26th, 202677.3%199,893 AF-481 AF
August 25th, 202677.5%200,374 AF-1,123 AF
August 24th, 202677.9%201,497 AF-160 AF
August 23rd, 202677.9%201,657 AF-805 AF
August 22nd, 202678.2%202,462 AF-805 AF
August 21st, 202678.6%203,267 AF-808 AF
August 20th, 202678.9%204,075 AF-808 AF
August 19th, 202679.2%204,883 AF-648 AF
August 18th, 202679.4%205,531 AF-811 AF
August 17th, 202679.8%206,342 AF-488 AF
August 16th, 202679.9%206,830 AF-650 AF
August 15th, 202680.2%207,480 AF-978 AF
August 14th, 202680.6%208,458 AF-816 AF
August 13th, 202680.9%209,274 AF-818 AF
August 12th, 202681.2%210,092 AF-491 AF
August 11th, 202681.4%210,583 AFFirst reading

Every reading is available in the open water record.