COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-08-19 09:41 PDT | ||
| Date/Time (PDT) | Pool Height | Date/Time (PDT) | Pool Height |
| 2026-08-20 00:00 | 1279.85 | 2026-08-20 05:00 | 1279.8 |
| 2026-08-19 00:00 | 1280.1 | 2026-08-20 11:00 | 1279.75 |
| 2026-08-18 00:00 | 1280.4 | 2026-08-20 17:00 | 1279.69 |
| 2026-08-17 00:00 | 1280.75 | 2026-08-20 23:00 | 1279.63 |
| 2026-08-16 00:00 | 1281.13 | 2026-08-21 05:00 | 1279.56 |
| 2026-08-15 00:00 | 1281.59 | 2026-08-21 11:00 | 1279.48 |
| 2026-08-14 00:00 | 1281.88 | 2026-08-21 17:00 | 1279.4 |
| 2026-08-13 00:00 | 1282.11 | 2026-08-21 23:00 | 1279.32 |
| 2026-08-12 00:00 | 1282.46 | 2026-08-22 05:00 | 1279.24 |
| 2026-08-11 00:00 | 1282.75 | 2026-08-22 11:00 | 1279.16 |
| 2026-08-10 00:00 | 1282.83 | 2026-08-22 17:00 | 1279.08 |
| 2026-08-22 23:00 | 1279 | ||
| 2026-08-23 05:00 | 1278.92 | ||
| 2026-08-23 11:00 | 1278.83 | ||
| 2026-08-23 17:00 | 1278.75 | ||
| 2026-08-23 23:00 | 1278.67 | ||
| 2026-08-24 05:00 | 1278.62 | ||
| 2026-08-24 11:00 | 1278.57 | ||
| 2026-08-24 17:00 | 1278.52 | ||
| 2026-08-24 23:00 | 1278.47 | ||
| 2026-08-25 05:00 | 1278.41 | ||
| 2026-08-25 11:00 | 1278.36 | ||
| 2026-08-25 17:00 | 1278.31 | ||
| 2026-08-25 23:00 | 1278.26 | ||
| 2026-08-26 05:00 | 1278.2 | ||
| 2026-08-26 11:00 | 1278.15 | ||
| 2026-08-26 17:00 | 1278.1 | ||
| 2026-08-26 23:00 | 1278.05 | ||
| 2026-08-27 05:00 | 1278 | ||
| 2026-08-27 11:00 | 1277.94 | ||
| 2026-08-27 17:00 | 1277.89 | ||
| 2026-08-27 23:00 | 1277.84 | ||
| 2026-08-28 05:00 | 1277.79 | ||
| 2026-08-28 11:00 | 1277.73 | ||
| 2026-08-28 17:00 | 1277.68 | ||
| 2026-08-28 23:00 | 1277.63 | ||
| 2026-08-29 05:00 | 1277.58 | ||