COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-10-28 08:27 PDT | ||
| Date/Time (PDT) | Pool Height | Date/Time (PDT) | Pool Height |
| 2026-10-29 00:00 | 1288.69 | 2026-10-29 11:00 | 1289.01 |
| 2026-10-28 00:00 | 1288.64 | 2026-10-29 17:00 | 1289.06 |
| 2026-10-27 00:00 | 1288.29 | 2026-10-29 23:00 | 1289.1 |
| 2026-10-26 00:00 | 1288.03 | 2026-10-30 05:00 | 1289.08 |
| 2026-10-25 00:00 | 1287.76 | 2026-10-30 11:00 | 1288.99 |
| 2026-10-24 00:00 | 1287.52 | 2026-10-30 17:00 | 1288.88 |
| 2026-10-23 00:00 | 1287.37 | 2026-10-30 23:00 | 1288.75 |
| 2026-10-22 00:00 | 1287.27 | 2026-10-31 05:00 | 1288.6 |
| 2026-10-21 00:00 | 1287.2 | 2026-10-31 11:00 | 1288.44 |
| 2026-10-20 00:00 | 1287.04 | 2026-10-31 17:00 | 1288.25 |
| 2026-10-19 00:00 | 1286.9 | 2026-11-01 00:00 | 1288.05 |
| 2026-11-01 05:00 | 1287.83 | ||
| 2026-11-01 11:00 | 1287.61 | ||
| 2026-11-01 17:00 | 1287.38 | ||
| 2026-11-01 23:00 | 1287.15 | ||
| 2026-11-02 05:00 | 1286.92 | ||
| 2026-11-02 11:00 | 1286.7 | ||
| 2026-11-02 17:00 | 1286.47 | ||
| 2026-11-02 23:00 | 1286.25 | ||
| 2026-11-03 05:00 | 1286.02 | ||
| 2026-11-03 11:00 | 1285.8 | ||
| 2026-11-03 17:00 | 1285.57 | ||
| 2026-11-03 23:00 | 1285.34 | ||
| 2026-11-04 05:00 | 1285.12 | ||
| 2026-11-04 11:00 | 1284.89 | ||
| 2026-11-04 17:00 | 1284.66 | ||
| 2026-11-04 23:00 | 1284.42 | ||
| 2026-11-05 05:00 | 1284.2 | ||
| 2026-11-05 11:00 | 1283.97 | ||
| 2026-11-05 17:00 | 1283.75 | ||
| 2026-11-05 23:00 | 1283.54 | ||
| 2026-11-06 05:00 | 1283.33 | ||
| 2026-11-06 11:00 | 1283.13 | ||
| 2026-11-06 17:00 | 1282.93 | ||
| 2026-11-06 23:00 | 1282.74 | ||
| 2026-11-07 05:00 | 1282.55 | ||