Recent Flooding along NE 132nd Street under I-405

The City of Kirkland has received questions related to the flooding along North East 132nd Street under I-405 that occurred earlier this week and is posting the following to inform our community about those events.  

To support pedestrian and motorist safety, NE 132nd Street under I-405 was temporarily closed both on Sunday and Wednesday due to standing water. Various factors led to the flooding, and measures have been put in place to avert the situation moving forward.   

For reference, the new I-405/NE 132nd Street interchange is still under construction, with a completion date of winter 2023/2024.  As such, the new storm system has not yet been fully constructed or connected to its final configuration.  Specifically, storm detention ponds and a new stream channel that will together store and move water through the interchange have not yet been built.  Additionally, a tributary of Juanita Creek that flows under I-405 is currently being pumped around its final stream channel.  These factors, combined with mechanical/electrical issues with two on-site pumps and significant rainfall over a short period of time, resulted in the system not being able to handle the amount of surface water entering the project site.  This overflow inundated the intersection. 

Since the events earlier this week, Graham Contracting, Ltd. has brought in additional pump capacity, added additional “pump watch” personnel to monitor the pump continuously, revised the storm discharge routing for more efficient flow, and brought in additional capacity to settle stormwater to remove sediment from the discharges. 

For additional information on this project, please visit the project webpage on the Washington State Department of Transportation website: https://wsdot.wa.gov/construction-planning/search-projects/i-405northeast-132nd-street-interchange-project