SUNDAY UPDATE: Some minor flooding possible along Cedar River

January 16, 2011 1:00 pm

Rainfall across King County has brought the Cedar River up to a Phase II flood level and a few locations in the basin may experience minor flooding, according to the King County Flood Warning Center.

The Cedar River was flowing at 2,890 cubic feet per second (CFS) at 7 p.m. The threshold for a Phase II flood alert on the Cedar is 2,800 CFS.

Here is the original Sunday story,

Controlled water releases from Howard Hanson Dam were expected to bring the Green River to a Phase II flood alert level sometime between 9 a.m. and noon on Sunday, according to the King County Flood Warning Center.

At that level, the only likely flooding impacts would occur in the rural areas without levees upstream of Auburn on the Green. These increased flows are not expected to have any impact on Auburn, Kent, Renton or Tukwila.

The Cedar River in Renton was below stage early Sunday.

Meanwhile, the warm wet Pineapple Express that’s lashing King County with heavy rain has brought the Snoqualmie River up to a Phase III flood alert level with moderate flooding possible throughout the Snoqualmie Valley, according to the flood warning center.

The high temperature in Renton Sunday is forecast for 56 degrees.

King County opened its warning center early Sunday morning to monitor rising flows on several King County rivers.

As of 3:30 a.m. Sunday, the total of the Snoqualmie River’s three forks was at 20,100 cubic feet per second (CFS), just past the Phase III flood alert threshold of 20,000 cfs. At this flow level, flooding of varied depths is expected to occur across the Snoqualmie Valley, and numerous roads could overtop and close.

Flows on the Tolt River remain within Phase II parameters. As of 3:15 a.m., the Tolt River was flowing at 3,770 CFS. Typically, only minor flooding would be expected at this flow.

The U.S. Corps of Engineers’ Seattle District has sent out flood fight teams statewide, including to the Green River, and the Corps’ Emergency Operations Center and Reservoir Control Center is operating around the clock.

The teams make on-the-spot visual assessments of river conditions and levee-system integrity and communicate information back to the Seattle District’s reservoir control center and emergency operations center.