New Warnings Could Help As White River Faces Perennial Flooding Risk
The official outlook for neutral or even weak La Niña winter weather means a likelihood of cooler and wetter conditions in Western Washington. That’s good news for skiers and snow pack. But it can also mean a higher than normal risk of flooding.
A new alert system in place on the White River should do a better job of warning people in chronically flood-prone areas south of Auburn.
The White River flows from the Emmons Glacier on Mount Rainier into the Puyallup near Sumner. Over the past 50 years or so, it’s been filing up with sediment, especially in the area near Auburn and below, where the slope of the river flattens.
“And so it just gets deposited as the river slows down and that’s the area where it naturally has been depositing,” said Brent Bower, a hydrologist with the National Weather Service in Seattle.
He says the capacity of the White River on that lower stretch has decreased so much that even pretty routine rainstorms can cause flooding in the area. So they’vebrought a new gage online to provide flood alerts for just the lower ten miles, rather than relying on a single one further upstream.
“Now we have a flood warning system that will address that area specifically with the river levels that are happening right at that area,” Bower said.
That means authorities will be able to better forecast even days in advance when flooding on the lower White River is likely. This should provide much better warnings for people who live and work in the communities of Auburn, Pacific and Sumner.