South Park Drainage and Roadway Partnership

Image map of project site.
South Park Drainage and Roadway Partnership project area

Project description

Improving chronic flooding and drainage issues in South Park
Seattle Public Utilities (SPU) and the Seattle Department of Transportation (SDOT) are working together on the South Park Drainage and Roadway Partnership project to construct 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.


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

What's happening now?

The project is in construction and will be completed by 2023.

Community benefits

Many of the streets in this area are 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. SPU and SDOT are partnering to reduce construction impacts on the community.

When complete, this project will work 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

In 2017, SPU gathered feedback from lower industrial basin businesses and residents on how they use the right-of-way and experience drainage and flooding issues. Based on community input and technical feasibility, the project team is moving forward with a design that features sidewalks, curbs and gutters with frequent inlets to drain the roadway. Specific features will vary between arterial and non-arterial streets.
In 2019, 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.
SPU is committed to providing timely information and updates on project activities. Updates may be available in multiple formats: the website, emails, and one-on-one briefings. Sign up for South Park project updates.

2015 – 2017

  • Schedule and scope development for stormwater drainage improvements

2018 – 2020 

  • Design

2021 – 2023 

  • Construction

Seattle Public Utilities is currently working on two other stormwater projects in South Park's lower industrial basin:

  1. flood control pump station to overcome the flooding effects of high tide.
  2. stormwater quality facility to treat stormwater from the storm drain system before it flows into the Duwamish Waterway.

Together, these projects will manage flooding and result in cleaner water and a healthier Duwamish River.
The northern industrial and residential area of South Park experiences chronic flooding for three reasons:

  1. The main drainage pipe to the Lower Duwamish Waterway is underwater during high tide, so the system cannot drain.
  2. Not all streets in the area have an adequate drainage collection system.
  3. Many private properties in the area do not have drainage pipes connected to the public drainage system.

The South Park Drainage and Roadway Partnership project is a partnership project between Seattle Public Utilities (SPU) and Seattle Department of Transportation (SDOT). The project is supported in part with funding from the King County Flood Control District and the levy to Move Seattle.

King County Flood Control District logo 

Public Utilities

Andrew Lee, General Manager and CEO
Address: 700 5th Avenue, Suite 4900, Seattle, WA, 98104
Mailing Address: PO Box 34018, Seattle, WA, 98124-5177
Phone: (206) 684-3000

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Seattle Public Utilities (SPU) is comprised of three major direct-service providing utilities: the Water Utility, the Drainage and Wastewater Utility, and the Solid Waste Utility.