Work crews will be installing a runoff filtration area near the southbound I-405 on-ramp from Coal Creek Parkway and the Lake Washington Loop Trail as part of the I-405/South Bellevue Widening Project. The project will help filter highway runoff before it is tested and released to Lake Washington.

Crews will remove tree limbs, trees and brush along the trail to make room for the runoff filtration area. Tree clearing may begin as early as March 16 and will be complete by April 15. Trail users may experience momentary delays and flaggers while work is underway. Crews will accommodate bicyclists and pedestrians as much as possible, but they should plan for delays of up to 10 or 15 minutes, according to WSDOT.