COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-11-12 08:57 PST | ||
| Date/Time (PST) | Pool Height | Date/Time (PST) | Pool Height |
| 2026-11-13 00:00 | 1285.55 | 2026-11-13 10:00 | 1285.15 |
| 2026-11-12 00:00 | 1286.11 | 2026-11-13 16:00 | 1285.02 |
| 2026-11-11 00:00 | 1286.51 | 2026-11-13 22:00 | 1284.89 |
| 2026-11-10 00:00 | 1287.15 | 2026-11-14 04:00 | 1284.76 |
| 2026-11-09 00:00 | 1287.51 | 2026-11-14 10:00 | 1284.63 |
| 2026-11-08 00:00 | 1287.71 | 2026-11-14 16:00 | 1284.49 |
| 2026-11-07 00:00 | 1287.92 | 2026-11-14 22:00 | 1284.36 |
| 2026-11-06 00:00 | 1288.29 | 2026-11-15 04:00 | 1284.21 |
| 2026-11-05 00:00 | 1288.83 | 2026-11-15 10:00 | 1284.07 |
| 2026-11-04 00:00 | 1289.12 | 2026-11-15 16:00 | 1283.92 |
| 2026-11-03 00:00 | 1288.93 | 2026-11-15 22:00 | 1283.77 |
| 2026-11-16 04:00 | 1283.62 | ||
| 2026-11-16 10:00 | 1283.46 | ||
| 2026-11-16 16:00 | 1283.31 | ||
| 2026-11-16 22:00 | 1283.15 | ||
| 2026-11-17 04:00 | 1283 | ||
| 2026-11-17 10:00 | 1282.85 | ||
| 2026-11-17 16:00 | 1282.7 | ||
| 2026-11-17 22:00 | 1282.56 | ||
| 2026-11-18 04:00 | 1282.42 | ||
| 2026-11-18 10:00 | 1282.28 | ||
| 2026-11-18 16:00 | 1282.14 | ||
| 2026-11-18 22:00 | 1282 | ||
| 2026-11-19 04:00 | 1281.86 | ||
| 2026-11-19 10:00 | 1281.72 | ||
| 2026-11-19 16:00 | 1281.58 | ||
| 2026-11-19 22:00 | 1281.44 | ||
| 2026-11-20 04:00 | 1281.3 | ||
| 2026-11-20 10:00 | 1281.15 | ||
| 2026-11-20 16:00 | 1281.01 | ||
| 2026-11-20 22:00 | 1280.87 | ||
| 2026-11-21 04:00 | 1280.72 | ||
| 2026-11-21 10:00 | 1280.58 | ||
| 2026-11-21 16:00 | 1280.43 | ||
| 2026-11-21 22:00 | 1280.29 | ||
| 2026-11-22 04:00 | 1280.14 | ||