COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-07-02 11:08 PDT | ||
| Date/Time (PDT) | Pool Height | Date/Time (PDT) | Pool Height |
| 2026-07-02 00:00 | 1285.6 | 2026-07-02 17:00 | 1285.92 |
| 2026-07-01 00:00 | 1285.76 | 2026-07-02 23:00 | 1286.02 |
| 2026-06-30 00:00 | 1285.92 | 2026-07-03 05:00 | 1286.12 |
| 2026-06-29 00:00 | 1285.92 | 2026-07-03 11:00 | 1286.22 |
| 2026-06-28 00:00 | 1285.37 | 2026-07-03 17:00 | 1286.32 |
| 2026-06-27 00:00 | 1285 | 2026-07-03 23:00 | 1286.41 |
| 2026-06-26 00:00 | 1285.19 | 2026-07-04 05:00 | 1286.51 |
| 2026-06-25 00:00 | 1285.39 | 2026-07-04 11:00 | 1286.61 |
| 2026-06-24 00:00 | 1285.23 | 2026-07-04 17:00 | 1286.71 |
| 2026-06-23 00:00 | 1285.1 | 2026-07-04 23:00 | 1286.81 |
| 2026-06-22 00:00 | 1284.66 | 2026-07-05 05:00 | 1286.9 |
| 2026-07-05 11:00 | 1287 | ||
| 2026-07-05 17:00 | 1287.13 | ||
| 2026-07-05 23:00 | 1287.25 | ||
| 2026-07-06 05:00 | 1287.38 | ||
| 2026-07-06 11:00 | 1287.5 | ||
| 2026-07-06 17:00 | 1287.63 | ||
| 2026-07-06 23:00 | 1287.75 | ||
| 2026-07-07 05:00 | 1287.88 | ||
| 2026-07-07 11:00 | 1288 | ||
| 2026-07-07 17:00 | 1288.13 | ||
| 2026-07-07 23:00 | 1288.25 | ||
| 2026-07-08 05:00 | 1288.37 | ||
| 2026-07-08 11:00 | 1288.5 | ||
| 2026-07-08 17:00 | 1288.62 | ||
| 2026-07-08 23:00 | 1288.75 | ||
| 2026-07-09 05:00 | 1288.87 | ||
| 2026-07-09 11:00 | 1289 | ||
| 2026-07-09 17:00 | 1289.02 | ||
| 2026-07-09 23:00 | 1289.03 | ||
| 2026-07-10 05:00 | 1289.05 | ||
| 2026-07-10 11:00 | 1289.07 | ||
| 2026-07-10 17:00 | 1289.09 | ||
| 2026-07-10 23:00 | 1289.1 | ||
| 2026-07-11 05:00 | 1289.12 | ||
| 2026-07-11 11:00 | 1289.14 | ||
| 2026-07-11 17:00 | 1289.16 | ||
| 2026-07-11 23:00 | 1289.17 | ||
| 2026-07-12 05:00 | 1289.19 | ||