South Park Drainage and Roadway Partnership

Project description

Improving chronic flooding and drainage issues in South Park

Seattle Public Utilities (SPU) has completed the South Park Drainage and Roadway Partnership project by constructing streets and a drainage system to improve chronic flooding and drainage issues. As part of the new drainage system, inlets and pipes will capture stormwater (rainfall runoff) and direct flows to the future pump station during hightide. The project is completed in partnership with Seattle Department of Transportation (SDOT) and supported in part with funding from the King County Flood Control District.

Location

South Park Industrial Area between 2nd Ave S and 8th Ave S, and S Holden St and S Monroe St.

Community benefits

Many of the streets in this area were in poor condition, which adversely affects water quality and impacts freight mobility. Rebuilding the roadways is an important part of this project for both SPU and SDOT, since it will allow streets to drain effectively into the new stormwater conveyance system.

This project works in tandem with the flood control pump station to reduce flooding in the industrial and residential areas in the northern part of South Park. The pipe improvements will collect and convey flows to the existing drainage system and lessen overall flooding. The drainage system will direct stormwater to the flood control pump station, which will pump stormwater to the Lower Duwamish Waterway, and to the future water quality facility.

Community engagement

Throughout the design phase from 2017 to 2020, SPU gathered feedback from lower industrial basin businesses and residents on how they use the right-of-way and experience drainage and flooding issues. We met one-on-one throughout the design process with impacted industrial businesses and property owners to gather feedback on business and access needs to inform project design.

Based on community input and technical feasibility, the project’s design features sidewalks, curbs, and gutters with frequent inlets to drain the roadway.

During construction between 2021 to 2023, SPU continued to work with impacted industrial businesses and property owners to keep them informed and to minimize construction impacts to the community.