Bonneville Dam & Lake on Columbia River
September 2026
| Day of Month | Total Generation MWh | Average Generation MW | Station Use MWh | Inflow kcfs | Total Outflow kcfs | Generation Flow kcfs | Spill kcfs | Midnight Reservoir Elevation | Average Forebay Elevation | Average Tailwater Elevation | Average Head feet | Project Average Tailwater | 2nd Powerhouse Total MWh | 2nd Powerhouse Flow kcfs |
|---|
| 1 | 8841 | 368 | 96 | 86.30 | 90.30 | 75.20 | 2.80 | 75.60 | 75.70 | 9.30 | 66.40 | 9.20 | 8547 | 72.70 |
| 2 | 8690 | 362 | 96 | 92.10 | 88.10 | 73.30 | 2.40 | 76.00 | 75.80 | 9.10 | 66.70 | 9.00 | 7178 | 61.00 |
| 3 | 8605 | 359 | 96 | 89.70 | 86.70 | 72.00 | 2.30 | 76.40 | 76.00 | 8.90 | 67.10 | 8.80 | 6330 | 53.50 |
| 4 | 9829 | 410 | 96 | 97.80 | 97.80 | 83.00 | 2.30 | 76.30 | 76.20 | 9.60 | 66.60 | 9.50 | 7616 | 64.90 |
| 5 | 7758 | 323 | 96 | 76.70 | 78.70 | 64.00 | 2.30 | 76.10 | 76.10 | 8.20 | 67.90 | 8.00 | 5502 | 45.80 |
| 6 | 7468 | 311 | 96 | 73.90 | 75.90 | 61.20 | 2.30 | 75.90 | 76.10 | 8.00 | 68.10 | 7.80 | 5178 | 43.00 |
| 7 | 7023 | 293 | 96 | 70.80 | 72.80 | 58.10 | 2.30 | 75.70 | 75.70 | 7.80 | 67.90 | 7.60 | 4808 | 40.30 |
| 8 | 7880 | 328 | 96 | 83.20 | 80.20 | 65.50 | 2.30 | 76.00 | 75.80 | 8.20 | 67.60 | 8.00 | 5635 | 47.40 |
| 9 | 7833 | 326 | 96 | 78.60 | 79.60 | 64.90 | 2.40 | 75.90 | 76.00 | 8.20 | 67.80 | 8.10 | 5556 | 46.60 |
| 10 | 8088 | 337 | 96 | 85.10 | 82.10 | 67.40 | 2.40 | 76.10 | 75.90 | 8.60 | 67.30 | 8.50 | 5813 | 48.90 |
| 11 | 7350 | 306 | 96 | 73.40 | 76.40 | 61.70 | 2.40 | 75.90 | 75.90 | 8.40 | 67.50 | 8.30 | 6584 | 55.50 |
| 12 | 7390 | 308 | 96 | 76.20 | 77.20 | 62.50 | 2.30 | 75.80 | 75.60 | 8.40 | 67.20 | 8.20 | 7390 | 62.50 |
| 13 | 7332 | 306 | 96 | 75.80 | 76.80 | 62.10 | 2.30 | 75.70 | 75.50 | 8.40 | 67.10 | 8.20 | 7332 | 62.10 |
| 14 | 7316 | 305 | 96 | 72.70 | 76.70 | 61.90 | 2.30 | 75.30 | 75.30 | 8.20 | 67.10 | 8.10 | 7163 | 60.70 |
| 15 | 6780 | 282 | 96 | 73.40 | 71.40 | 56.70 | 2.30 | 75.50 | 75.40 | 7.50 | 67.90 | 7.50 | 6780 | 56.70 |
| 16 | 6929 | 289 | 96 | 74.50 | 72.60 | 57.90 | 2.30 | 75.60 | 75.50 | 7.40 | 68.10 | 7.30 | 6929 | 57.90 |
| 17 | 6957 | 290 | 96 | 71.60 | 72.60 | 57.90 | 2.30 | 75.50 | 75.40 | 7.20 | 68.20 | 7.00 | 6957 | 57.90 |
| 18 | 6944 | 289 | 96 | 73.50 | 72.50 | 57.80 | 2.30 | 75.70 | 75.40 | 7.10 | 68.30 | 7.00 | 6944 | 57.80 |
| 19 | 7284 | 304 | 96 | 77.20 | 75.20 | 60.50 | 2.40 | 75.90 | 75.80 | 7.30 | 68.50 | 7.10 | 7284 | 60.50 |
| 20 | 7229 | 301 | 96 | 76.60 | 74.60 | 59.80 | 2.40 | 76.10 | 76.00 | 7.30 | 68.70 | 7.10 | 7229 | 59.80 |
| 21 | 7731 | 322 | 96 | 77.20 | 79.20 | 64.50 | 2.40 | 75.80 | 75.90 | 7.80 | 68.10 | 7.60 | 7731 | 64.50 |
| 22 | 7079 | 295 | 96 | 72.60 | 73.60 | 58.70 | 2.50 | 75.80 | 75.80 | 7.40 | 68.40 | 7.20 | 7059 | 58.50 |
| 23 | 7065 | 294 | 96 | 72.60 | 73.60 | 58.80 | 2.30 | 75.70 | 75.60 | 7.40 | 68.20 | 7.20 | 7065 | 58.80 |
| 24 | 7811 | 325 | 96 | 72.50 | 80.50 | 65.80 | 2.30 | 74.90 | 75.30 | 7.90 | 67.40 | 7.80 | 7811 | 65.80 |
| 25 | 8230 | 343 | 96 | 86.70 | 84.70 | 70.00 | 2.30 | 75.40 | 75.20 | 8.50 | 66.70 | 8.50 | 7920 | 67.50 |
| 26 | 7740 | 322 | 96 | 74.20 | 81.20 | 66.50 | 2.30 | 74.40 | 74.60 | 8.40 | 66.20 | 8.30 | 7740 | 66.50 |
| 27 | 8513 | 355 | 96 | 85.30 | 88.30 | 73.60 | 2.30 | 74.10 | 74.10 | 8.70 | 65.40 | 8.60 | 8190 | 70.90 |
| 28 | 8997 | 375 | 96 | 87.70 | 93.70 | 79.00 | 2.30 | 73.50 | 73.30 | 9.00 | 64.30 | 9.20 | 7466 | 65.90 |
| 29 | 9610 | 400 | 96 | 94.40 | 98.40 | 83.70 | 2.30 | 73.10 | 73.30 | 9.50 | 63.80 | 9.60 | 7286 | 63.90 |
| 30 | 7163 | 298 | 96 | 88.70 | 75.70 | 61.00 | 2.30 | 74.40 | 73.50 | 7.90 | 65.60 | 8.20 | 6067 | 60.30 |
|
| TOT | 233465 | | 2880 | | | | | | | | | | | |
| AVG | 7782 | 324 | 96 | 79.70 | 80.24 | 65.50 | 2.35 | 75.47 | 75.39 | 8.19 | 67.20 | 8.08 | 6903 | 58.60 |
|
| MAX | 9829 | | | 97.80 | 98.40 | 83.70 | 2.80 | 76.40 | 76.20 | 9.60 | 68.70 | 9.60 | 8547 | 72.70 |
| MIN | 6780 | | | 70.80 | 71.40 | 56.70 | 2.30 | 73.10 | 73.30 | 7.10 | 63.80 | 7.00 | 4808 | 40.30 |