King County Flood Warning Center issues Phase 3 flood alert for Green River
Published 10:00 am Wednesday, November 18, 2015
For the Reporter
Planned water releases from a flood-control dam in the upper Green River watershed have brought the river up to a Phase 3 flood alert level Wednesday, with moderate flooding possible in the largely agricultural middle Green River Valley.
The King County Flood Warning Center, which has been monitoring countywide flooding for more than 24 hours, issues flood alerts for the Green River based on planned water releases from Howard Hanson Dam, several miles upstream of Auburn.
Flows from those controlled water releases are expected to reach 9,000 cubic feet per second (CFS) later this morning at the river gage near Auburn.
At these flows, flooding of varied depths is possible in the Green River Valley upstream of Auburn. Southeast Green Valley Road and the West Valley Road could overtop with floodwaters, while flooding could also occur in the lower Mill Creek basin.
More densely populated and developed areas of the Green River Valley downstream of Auburn are not expected to be impacted by river flooding.
Drier weather is slowly bringing improved flood conditions to rain-swollen rivers across much of King County on Wednesday, with the notable exception of the lower Snoqualmie River Valley, where floodwaters remain high.
The sum of the Snoqualmie River’s three forks crested at 7:15 p.m. Tuesday at a reading of 42,370 CFS, well above the Phase 4 flood alert threshold of 38,000 CFS. Floodwaters inundated much of the Snoqualmie Valley, and flows in the lower valley – particularly from the Carnation area to downstream past Duvall – remain very high.
Flood Warning Center employees will continue to monitor stream gages and weather reports, and will provide updated information on river conditions as necessary. Real-time river level information is available online at kingcounty.gov/flood.
During river flooding events, King County serves as a clearinghouse for information on flood conditions, operating a recorded message center with continuous updates of river gage readings and flood phases and other related information. Reach the Flood Warning Center at 206-296-8200 or 1-800-945-9263. Interpreter assistance in multiple languages is available.
