COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-01-11 09:13 PST | ||
| Date/Time (PST) | Pool Height | Date/Time (PST) | Pool Height |
| 2026-01-12 00:00 | 1284.03 | 2026-01-12 10:00 | 1283.83 |
| 2026-01-11 00:00 | 1283.97 | 2026-01-12 16:00 | 1283.73 |
| 2026-01-10 00:00 | 1283.89 | 2026-01-12 22:00 | 1283.63 |
| 2026-01-09 00:00 | 1283.98 | 2026-01-13 04:00 | 1283.52 |
| 2026-01-08 00:00 | 1284.2 | 2026-01-13 10:00 | 1283.41 |
| 2026-01-07 00:00 | 1284.6 | 2026-01-13 16:00 | 1283.3 |
| 2026-01-06 00:00 | 1285.04 | 2026-01-13 22:00 | 1283.18 |
| 2026-01-05 00:00 | 1284.86 | 2026-01-14 04:00 | 1283.07 |
| 2026-01-04 00:00 | 1284.39 | 2026-01-14 10:00 | 1282.95 |
| 2026-01-03 00:00 | 1284.56 | 2026-01-14 16:00 | 1282.84 |
| 2026-01-02 00:00 | 1285.09 | 2026-01-14 22:00 | 1282.72 |
| 2026-01-15 04:00 | 1282.68 | ||
| 2026-01-15 10:00 | 1282.64 | ||
| 2026-01-15 16:00 | 1282.6 | ||
| 2026-01-15 22:00 | 1282.56 | ||
| 2026-01-16 04:00 | 1282.52 | ||
| 2026-01-16 10:00 | 1282.48 | ||
| 2026-01-16 16:00 | 1282.44 | ||
| 2026-01-16 22:00 | 1282.4 | ||
| 2026-01-17 04:00 | 1282.36 | ||
| 2026-01-17 10:00 | 1282.32 | ||
| 2026-01-17 16:00 | 1282.28 | ||
| 2026-01-17 22:00 | 1282.24 | ||
| 2026-01-18 04:00 | 1282.2 | ||
| 2026-01-18 10:00 | 1282.16 | ||
| 2026-01-18 16:00 | 1282.12 | ||
| 2026-01-18 22:00 | 1282.08 | ||
| 2026-01-19 04:00 | 1282.04 | ||
| 2026-01-19 10:00 | 1282 | ||
| 2026-01-19 16:00 | 1281.96 | ||
| 2026-01-19 22:00 | 1281.92 | ||
| 2026-01-20 04:00 | 1281.88 | ||
| 2026-01-20 10:00 | 1281.84 | ||
| 2026-01-20 16:00 | 1281.8 | ||
| 2026-01-20 22:00 | 1281.76 | ||
| 2026-01-21 04:00 | 1281.72 | ||