COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-07-14 09:43 PDT | ||
| Date/Time (PDT) | Pool Height | Date/Time (PDT) | Pool Height |
| 2026-07-14 00:00 | 1288.74 | 2026-07-14 23:00 | 1288.38 |
| 2026-07-13 00:00 | 1288.98 | 2026-07-15 05:00 | 1288.31 |
| 2026-07-12 00:00 | 1289.15 | 2026-07-15 11:00 | 1288.24 |
| 2026-07-11 00:00 | 1289.21 | 2026-07-15 17:00 | 1288.18 |
| 2026-07-10 00:00 | 1289.11 | 2026-07-15 23:00 | 1288.11 |
| 2026-07-09 00:00 | 1288.84 | 2026-07-16 05:00 | 1288.04 |
| 2026-07-08 00:00 | 1288.3 | 2026-07-16 11:00 | 1287.98 |
| 2026-07-07 00:00 | 1287.59 | 2026-07-16 17:00 | 1287.91 |
| 2026-07-06 00:00 | 1286.88 | 2026-07-16 23:00 | 1287.84 |
| 2026-07-05 00:00 | 1286.51 | 2026-07-17 05:00 | 1287.76 |
| 2026-07-04 00:00 | 1286.25 | 2026-07-17 11:00 | 1287.69 |
| 2026-07-17 17:00 | 1287.61 | ||
| 2026-07-17 23:00 | 1287.54 | ||
| 2026-07-18 05:00 | 1287.46 | ||
| 2026-07-18 11:00 | 1287.38 | ||
| 2026-07-18 17:00 | 1287.3 | ||
| 2026-07-18 23:00 | 1287.21 | ||
| 2026-07-19 05:00 | 1287.13 | ||
| 2026-07-19 11:00 | 1287.04 | ||
| 2026-07-19 17:00 | 1286.96 | ||
| 2026-07-19 23:00 | 1286.87 | ||
| 2026-07-20 05:00 | 1286.78 | ||
| 2026-07-20 11:00 | 1286.69 | ||
| 2026-07-20 17:00 | 1286.6 | ||
| 2026-07-20 23:00 | 1286.5 | ||
| 2026-07-21 05:00 | 1286.41 | ||
| 2026-07-21 11:00 | 1286.31 | ||
| 2026-07-21 17:00 | 1286.21 | ||
| 2026-07-21 23:00 | 1286.11 | ||
| 2026-07-22 05:00 | 1286.01 | ||
| 2026-07-22 11:00 | 1285.9 | ||
| 2026-07-22 17:00 | 1285.8 | ||
| 2026-07-22 23:00 | 1285.69 | ||
| 2026-07-23 05:00 | 1285.58 | ||
| 2026-07-23 11:00 | 1285.47 | ||
| 2026-07-23 17:00 | 1285.36 | ||
| 2026-07-23 23:00 | 1285.24 | ||
| 2026-07-24 05:00 | 1285.13 | ||