148th Avenue Southeast at Larsen Lake Flood Mitigation

This project aims to reduce the frequency of flooding on 148th Avenue Southeast between Southeast Eighth Street and Main Street. Currently, the project team is performing engineering studies and evaluating options to develop a design that reduces or eliminates roadway flooding in the project area. Proposed solutions will also consider the effects on habitat and fish passage, drainage flow improvements, maintenance and cost-effectiveness. 

The City of Bellevue and King County are working together to develop and implement a future design to provide healthier stormwater drainage between Larsen Lake/Lake Hills Greenbelt and Upper Kelsey Creek.

 Project area map

Background

Following moderate to heavy rain or long rain events, 148th Avenue has been fully or partially closed by the city due to high water levels on numerous occasions between Southeast Eighth Street and Main Street.

The 148th Avenue corridor is the only major north-south arterial roadway in East Bellevue, a federally designated truck route, and a critical commuter and emergency services access route between Interstate 90 (I-90) and State Route 520 (SR 520) with an average daily traffic over 33,000 vehicles. 

During closures, adjacent corridors, including residential areas with limited vehicle capacity, have been impacted. Flooding also threatens nearby parklands, blueberry fields and residences. 

The city will reduce negative impacts in the project area through the planned mitigation measures by reducing the recurrence of flooding, and preventing further roadway sinkage and culverts from warping.