South Park Pump Station

Rendering of proposed design for South Park Pump Station, aerial perspective
Proposed design for South Park Pump Station, aerial view.

Project description

Improving chronic flooding and drainage issues in South Park
SPU is building a pump station which will send stormwater runoff to the Duwamish Waterway during high tide events when the storm drain system cannot drain by gravity. In doing so, the pump station will reduce flooding on roads that have a formal stormwater collection system (including catch basins and inlets). This project will work in unison with the South Park Drainage and Roadway Partnership project to reduce flooding in the South Park lower industrial basin.


636 and 640 S Riverside Drive

What's happening now?

Pump station construction is underway. The contractor may temporarily store equipment in some areas currently used for street parking as permitted by the Seattle Department of Transportation.

Community benefits

When complete, this project will pump stormwater from South Park's lower industrial basin into the Lower Duwamish Waterway, preventing water from backing up in the pipes during high tide and causing flooding.

Anticipated impacts

You can expect:

  • Typical work hours are weekdays from 7 a.m. to 7 p.m., and Saturday work may be required to meet construction deadlines.
  • Construction best practices to control noise, dust, dirt, and vibration
  • Increased construction traffic
  • Equipment and material staging near the pump station site

Community engagement

Throughout project design, the project team met one-on-one with adjacent industrial businesses and property owners to gather feedback 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.

Rendering of proposed design for South Park Pump Station
Proposed design for South Park Pump Station.

2017 - 2019

  • Design, permitting and real property work for pump station

2020 - 2023 

  • Construction


  • Testing and completion

Seattle Public Utilities is currently working on two other stormwater projects in South Park's lower industrial basin to reduce flooding and improve water quality in the Lower Duwamish Waterway:

  1. A South Park Drainage and Roadway Partnership project to construct streets and a drainage system to improve chronic flooding and drainage issues.
  2. stormwater quality facility to treat stormwater from the storm drain system before it flows into the Duwamish Waterway.

The northern industrial and residential area of South Park experiences chronic flooding for three reasons:

The main drainage pipe to the Lower Duwamish Waterway is underwater during high tide.
When it rains during high tides, the main pipe in 7th Ave S that flows to the Duwamish Waterway cannot drain out to the river, and water backs up in the drainage system. Rain falling in the lower areas of the basin cannot flow out, and water in the main pipe can sometimes flow back out of inlets and catch basins, flooding the neighborhood. A pump station will allow the main pipe to drain during high tides and relieve flooding in areas that have a drainage system in place.

Not all streets in the area have a drainage collection system.
Additional conveyance improvements will not be fully effective until the pump station is installed so that the pipes can drain at high tide. When additional roadway drainage is built, it will connect to the main pipe in 7th Ave S and the pump station will allow the system to drain when the tides are high.

Many private properties in the basin do not have drainage pipes connected to the public drainage system.
Some properties are lower than the street or are located along streets where there is no existing collection system. In these areas, individual property owners may want to make site improvements to connect to a public drainage system in the street once one is available.

The project is supported in part with funding from the King County Flood Control District.

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.