COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-06-23 08:58 PDT | ||
| Date/Time (PDT) | Pool Height | Date/Time (PDT) | Pool Height |
| 2026-06-23 00:00 | 1285.1 | 2026-06-23 17:00 | 1285.17 |
| 2026-06-22 00:00 | 1284.66 | 2026-06-23 23:00 | 1285.13 |
| 2026-06-21 00:00 | 1283.69 | 2026-06-24 05:00 | 1285.1 |
| 2026-06-20 00:00 | 1282.98 | 2026-06-24 11:00 | 1285.07 |
| 2026-06-19 00:00 | 1282.95 | 2026-06-24 17:00 | 1285.06 |
| 2026-06-18 00:00 | 1282.21 | 2026-06-24 23:00 | 1285.05 |
| 2026-06-17 00:00 | 1281.32 | 2026-06-25 05:00 | 1285.04 |
| 2026-06-16 00:00 | 1281.16 | 2026-06-25 11:00 | 1285.04 |
| 2026-06-15 00:00 | 1281.43 | 2026-06-25 17:00 | 1285.04 |
| 2026-06-14 00:00 | 1281.55 | 2026-06-25 23:00 | 1285.05 |
| 2026-06-13 00:00 | 1281.58 | 2026-06-26 05:00 | 1285.05 |
| 2026-06-26 11:00 | 1285.04 | ||
| 2026-06-26 17:00 | 1285.04 | ||
| 2026-06-26 23:00 | 1285.02 | ||
| 2026-06-27 05:00 | 1285.01 | ||
| 2026-06-27 11:00 | 1284.99 | ||
| 2026-06-27 17:00 | 1284.98 | ||
| 2026-06-27 23:00 | 1284.98 | ||
| 2026-06-28 05:00 | 1284.97 | ||
| 2026-06-28 11:00 | 1284.96 | ||
| 2026-06-28 17:00 | 1285.03 | ||
| 2026-06-28 23:00 | 1285.1 | ||
| 2026-06-29 05:00 | 1285.17 | ||
| 2026-06-29 11:00 | 1285.24 | ||
| 2026-06-29 17:00 | 1285.31 | ||
| 2026-06-29 23:00 | 1285.38 | ||
| 2026-06-30 05:00 | 1285.45 | ||
| 2026-06-30 11:00 | 1285.51 | ||
| 2026-06-30 17:00 | 1285.58 | ||
| 2026-06-30 23:00 | 1285.65 | ||
| 2026-07-01 05:00 | 1285.72 | ||
| 2026-07-01 11:00 | 1285.79 | ||
| 2026-07-01 17:00 | 1285.86 | ||
| 2026-07-01 23:00 | 1285.93 | ||
| 2026-07-02 05:00 | 1286 | ||
| 2026-07-02 11:00 | 1286.07 | ||
| 2026-07-02 17:00 | 1286.13 | ||
| 2026-07-02 23:00 | 1286.2 | ||
| 2026-07-03 05:00 | 1286.27 | ||