King County has filed a land use application to build a 1.25-million-gallon underground storage facility near the intersection of SW Michigan St and 2nd Ave SW to hold stormwater and wastewater that currently overflows into the Duwamish River during large storms.

The water in the storage facility will then flow to the West Point Treatment Plant for treatment before it is safely released into Puget Sound. This storage facility will reduce overflows and pollution into the Duwamish River. The County will also build supporting infrastructure underneath West Marginal Way SW.

The project has recently reached the 60 per cent design milestone. At 60 per cent design, the project details are determined including equipment, architecture, landscaping, and contractor documents (design drawings and specifications). The project team is now focused on finalizing design details and preparing for construction, which will begin in 2025.