COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-09-26 10:20 PDT | ||
| Date/Time (PDT) | Inflow | Date/Time (PDT) | Inflow |
| 2026-09-27 00:00 | 74600 | 2026-09-27 05:00 | 75228.65 |
| 2026-09-26 00:00 | 62200 | 2026-09-27 11:00 | 76064.87 |
| 2026-09-25 00:00 | 75400 | 2026-09-27 17:00 | 76242.7 |
| 2026-09-24 00:00 | 77100 | 2026-09-27 23:00 | 76140.8 |
| 2026-09-23 00:00 | 70000 | 2026-09-28 05:00 | 76067.75 |
| 2026-09-22 00:00 | 70500 | 2026-09-28 11:00 | 76005.09 |
| 2026-09-21 00:00 | 66100 | 2026-09-28 17:00 | 75887.11 |
| 2026-09-20 00:00 | 60300 | 2026-09-28 23:00 | 75666.52 |
| 2026-09-19 00:00 | 70500 | 2026-09-29 05:00 | 75064.44 |
| 2026-09-18 00:00 | 63800 | 2026-09-29 11:00 | 73457.05 |
| 2026-09-17 00:00 | 62800 | 2026-09-29 17:00 | 71051.91 |
| 2026-09-29 23:00 | 69102.98 | ||
| 2026-09-30 05:00 | 67952.31 | ||
| 2026-09-30 11:00 | 66688.16 | ||
| 2026-09-30 17:00 | 65008.9 | ||
| 2026-09-30 23:00 | 63632.02 | ||
| 2026-10-01 05:00 | 62966.42 | ||
| 2026-10-01 11:00 | 62816.71 | ||
| 2026-10-01 17:00 | 62927 | ||
| 2026-10-01 23:00 | 63069.3 | ||
| 2026-10-02 05:00 | 63104.05 | ||
| 2026-10-02 11:00 | 63026.3 | ||
| 2026-10-02 17:00 | 62853.58 | ||
| 2026-10-02 23:00 | 62590.58 | ||
| 2026-10-03 05:00 | 62203.07 | ||
| 2026-10-03 11:00 | 61603.18 | ||
| 2026-10-03 17:00 | 60841.17 | ||
| 2026-10-03 23:00 | 60165.43 | ||
| 2026-10-04 05:00 | 59724.92 | ||
| 2026-10-04 11:00 | 59466.65 | ||
| 2026-10-04 17:00 | 59306.94 | ||
| 2026-10-04 23:00 | 59200.5 | ||
| 2026-10-05 05:00 | 59128.36 | ||
| 2026-10-05 11:00 | 59120.33 | ||
| 2026-10-05 17:00 | 59219.4 | ||
| 2026-10-05 23:00 | 59341.08 | ||
| 2026-10-06 05:00 | 59444.77 | ||