COLUMBIA--GRAND COULEE DAM (GCDW1)
| Observed | Forecast/Trend Issued: 2026-06-07 09:43 PDT | ||
| Date/Time (PDT) | Pool Height | Date/Time (PDT) | Pool Height |
| 2026-06-08 00:00 | 1277.18 | 2026-06-08 11:00 | 1276.98 |
| 2026-06-07 00:00 | 1276.41 | 2026-06-08 17:00 | 1276.97 |
| 2026-06-06 00:00 | 1275.95 | 2026-06-08 23:00 | 1276.94 |
| 2026-06-05 00:00 | 1275.47 | 2026-06-09 05:00 | 1276.92 |
| 2026-06-04 00:00 | 1275.22 | 2026-06-09 11:00 | 1276.88 |
| 2026-06-03 00:00 | 1274.97 | 2026-06-09 17:00 | 1276.85 |
| 2026-06-02 00:00 | 1274.57 | 2026-06-09 23:00 | 1276.81 |
| 2026-06-01 00:00 | 1273.64 | 2026-06-10 05:00 | 1276.77 |
| 2026-05-31 00:00 | 1271.93 | 2026-06-10 11:00 | 1276.73 |
| 2026-05-30 00:00 | 1270.22 | 2026-06-10 17:00 | 1276.69 |
| 2026-05-29 00:00 | 1269.38 | 2026-06-10 23:00 | 1276.65 |
| 2026-06-11 05:00 | 1276.62 | ||
| 2026-06-11 11:00 | 1276.58 | ||
| 2026-06-11 17:00 | 1276.54 | ||
| 2026-06-11 23:00 | 1276.5 | ||
| 2026-06-12 05:00 | 1276.45 | ||
| 2026-06-12 11:00 | 1276.41 | ||
| 2026-06-12 17:00 | 1276.35 | ||
| 2026-06-12 23:00 | 1276.29 | ||
| 2026-06-13 05:00 | 1276.23 | ||
| 2026-06-13 11:00 | 1276.16 | ||
| 2026-06-13 17:00 | 1276.15 | ||
| 2026-06-13 23:00 | 1276.21 | ||
| 2026-06-14 05:00 | 1276.27 | ||
| 2026-06-14 11:00 | 1276.33 | ||
| 2026-06-14 17:00 | 1276.39 | ||
| 2026-06-14 23:00 | 1276.46 | ||
| 2026-06-15 05:00 | 1276.53 | ||
| 2026-06-15 11:00 | 1276.61 | ||
| 2026-06-15 17:00 | 1276.74 | ||
| 2026-06-15 23:00 | 1276.89 | ||
| 2026-06-16 05:00 | 1277.05 | ||
| 2026-06-16 11:00 | 1277.22 | ||
| 2026-06-16 17:00 | 1277.39 | ||
| 2026-06-16 23:00 | 1277.56 | ||
| 2026-06-17 05:00 | 1277.72 | ||