COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-08-26 08:41 PDT | ||
| Date/Time (PDT) | Pool Height | Date/Time (PDT) | Pool Height |
| 2026-08-26 00:00 | 1278.3 | 2026-08-26 11:00 | 1277.86 |
| 2026-08-25 00:00 | 1278.7 | 2026-08-26 17:00 | 1277.82 |
| 2026-08-24 00:00 | 1278.99 | 2026-08-26 23:00 | 1277.78 |
| 2026-08-23 00:00 | 1278.98 | 2026-08-27 05:00 | 1277.74 |
| 2026-08-22 00:00 | 1279.08 | 2026-08-27 11:00 | 1277.7 |
| 2026-08-21 00:00 | 1279.41 | 2026-08-27 17:00 | 1277.67 |
| 2026-08-20 00:00 | 1279.85 | 2026-08-27 23:00 | 1277.63 |
| 2026-08-19 00:00 | 1280.1 | 2026-08-28 05:00 | 1277.59 |
| 2026-08-18 00:00 | 1280.4 | 2026-08-28 11:00 | 1277.55 |
| 2026-08-17 00:00 | 1280.75 | 2026-08-28 17:00 | 1277.51 |
| 2026-08-16 00:00 | 1281.13 | 2026-08-28 23:00 | 1277.47 |
| 2026-08-29 05:00 | 1277.43 | ||
| 2026-08-29 11:00 | 1277.39 | ||
| 2026-08-29 17:00 | 1277.35 | ||
| 2026-08-29 23:00 | 1277.31 | ||
| 2026-08-30 05:00 | 1277.28 | ||
| 2026-08-30 11:00 | 1277.24 | ||
| 2026-08-30 17:00 | 1277.2 | ||
| 2026-08-30 23:00 | 1277.16 | ||
| 2026-08-31 05:00 | 1277.12 | ||
| 2026-08-31 11:00 | 1277.08 | ||
| 2026-08-31 17:00 | 1277.04 | ||
| 2026-08-31 23:00 | 1277 | ||
| 2026-09-01 05:00 | 1276.96 | ||
| 2026-09-01 11:00 | 1276.91 | ||
| 2026-09-01 17:00 | 1276.86 | ||
| 2026-09-01 23:00 | 1276.83 | ||
| 2026-09-02 05:00 | 1276.79 | ||
| 2026-09-02 11:00 | 1276.77 | ||
| 2026-09-02 17:00 | 1276.75 | ||
| 2026-09-02 23:00 | 1276.73 | ||
| 2026-09-03 05:00 | 1276.72 | ||
| 2026-09-03 11:00 | 1276.72 | ||
| 2026-09-03 17:00 | 1276.72 | ||
| 2026-09-03 23:00 | 1276.73 | ||
| 2026-09-04 05:00 | 1276.74 | ||
| 2026-09-04 11:00 | 1276.76 | ||
| 2026-09-04 17:00 | 1276.77 | ||
| 2026-09-04 23:00 | 1276.79 | ||
| 2026-09-05 05:00 | 1276.8 | ||