High tides, low pressure to blame for coastal flooding

Published 1:30 am Friday, January 6, 2023

Last Tuesday’s coastal flooding in the Snohomish River estuary was attributed to a high tide and a low barometric pressure. The Ebey Island dikes and also the Sunnyside dike had up to 12 inches of overtopping on that day. The predicted high tide was lower than the day prior.

The Snohomish River flow was higher but below flood stage. It was the low pressure that pushes the water over the dikes. Up to 12 inches of overtopping was experienced at several locations on Ebey Island and on the Sunnyside dikes east of Ebey Slough. It was caused by a natural phenomenon, not climate change.

Dan Bartelheimer

Snohomish