Army Corps monitoring Green and White river dams as storm waters reach peak
Reservoirs on two area rivers are filling fast, and the U.S. Army Corps of Engineers has spotters keeping an eye on them 24 hours a day.
The Corps said it’s running its Reservoir Control and Emergency Operations centers around the clock to monitor conditions on the Green and White rivers.
The Corps is monitoring both the weather and reservoir storage at their two dams near Enumclaw: Mud Mountain Dam on the White River and Howard A. Hanson Dam on the Green River.
The water volumes projected to flow into the dams are within the scope of what the dams are designed to handle, the Corps said in a statement Thursday afternoon.
“But Corps staff must manage the reservoir storage space carefully to prevent overfilling the reservoirs,” the Corps said.
“Earlier this week, we were pushing outflows to reduce both dams’ pools and make reservoir space,” said senior water manager Jon Moen. “We are now again storing water to reduce outflows and greatly reduce flood risk on those rivers as the event ramps up.”
A series of storms have saturated the ground in Western Washington and put creeks and rivers at or near the flood stage.
Moen expects inflows to the dams to peak late Thursday or early Friday.
“This is a significant event with the potential to reach inflow levels not seen in over ten years,” said Moen.
Completed in 1948, Mud Mountain Dam’s purpose is to manage flood risk. When completely filled, the reservoir stretches 5.5 miles and covers 1,200 acres.
The Corps’ river spotters are in the Pacific and Sumner areas to monitor the unpredictable channel capacity of the White River.
“Historically, large channel capacity losses have happened in these areas,” the Corps said.
Completed in 1961, the Howard Hanson Dam’s primary purposes are flood control, fish enhancement and water conservation. During winter, the reservoir is usually kept nearly empty in case it’s needed for conditions such as the region is currently experiencing.
