Longfellow Starts Here

Photo of woods area with a footbridge

Project description

Seattle Public Utilities is working to improve the sewer system in the South Delridge community (South Delridge, Roxhill, Westwood, Highland Park, Riverview, and Puget Ridge neighborhoods) as well as reduce pollution in Longfellow Creek.

During heavy rain events, stormwater can overwhelm the sewer system and cause Combined Sewer Overflows (CSOs) resulting in untreated sewage discharge into Longfellow Creek.

In addition, when it rains, stormwater runoff from roads and other hard surfaces collected by SPU’s drainage pipes carry pollutants into Longfellow Creek. These pollutants are harmful to aquatic habitats.

Both types of pollution can be harmful to humans and the environment.

To reduce CSOs, improve water quality in Longfellow Creek, and provide other benefits to the community, SPU plans to make infrastructure investments in South Delridge, a community that has experienced a historic lack of investment.

SPU is collaborating with South Delridge communities, the Office of Planning and Community Development (OPCD), the Department of Neighborhoods (DON), and SPU's consultant team to center racial and social equity throughout this work to determine how and where these investments should be made. This project is a chance to improve upon the way utility management and urban planning has traditionally been done by partnering with the community. SPU is planning to work with communities to create a plan together that respects and enhances the way that communities use their community space. In this journey, we hope to combine our expertise, knowledge, and visions to ideate, create, grow, and succeed together.


South Delridge (South Delridge, Roxhill, Westwood, Highland Park, Riverview, and Puget Ridge neighborhoods) is one of the most diverse neighborhoods in Seattle. It is home to several immigrant, religious, racial, multicultural, and multiracial ethnic communities.

Delridge has a distinct topography and a range of ecosystems. As the name implies, the landscape is characterized by dells and ridges which has resulted in limited east to west connectivity. Many areas also lack safe sidewalks and bike lanes, and experience flooding and drainage issues. 

Map image with border overlay
The South Delridge community (South Delridge, Roxhill, Westwood, Highland Park, Riverview, and Puget Ridge neighborhoods).

Visit the project area map

What's happening now?

In 2021, the project team paused work on the Longfellow Starts Here project due to the COVID-19 pandemic and the challenges it presented to continuing effective and meaningful community conversations and outreach. We are now resuming work on the project and will provide further updates as we identify next steps. We look forward to reengaging with the community and renewing our partnership with the Innovation Team.

Sign up for project email list to stay updated on our next steps for the project.

Community benefits

We are focused on improving water quality in Longfellow Creek, investing in meaningful infrastructure, and meeting the needs of the South Delridge community. To do this, we will be creative about ways to improve the health and wellbeing of residents, particularly youth and the elderly.

To improve environmental and public health we will pursue partnerships with community members, schools, and other community organizations in the area. We are actively seeking ways to incorporate environmental and health-related benefits into the project.

Community involvement

There will be multiple opportunities to share feedback and learn more about the project.

Sign up for project updates here.

Check back here for more information about ways to get involved. If you have ideas for your neighborhood or are part of a community group that would like to be involved as we restart the planning process, please reach out to Shanti Colwell at Shanti.Colwell@seattle.gov.

The Innovation Team is a group of community co-creators who will help guide and collaborate with the project during its early planning phases. This team of South Delridge residents and enthusiasts was convened in early 2020 to work with the project team to identify important places, projects, and passions of the community. We are excited to partner with the Innovation Team and other members of the community as we approach our work in project planning and infrastructure improvements in new ways.

Phase 1 (2020 to 2025)

  • Engage and learn from the community to identify:
    • Community-led initiatives
    • Loved spaces
    • Community priorities and needs around mobility, open space, etc.
    • Other community-driven visions
  • Collect technical data to better understand the opportunities and limits of the environment
  • Work with the community to pair technical tools with place-based concepts to manage stormwater while keeping and amplifying public space
  • Plan and design new infrastructure in partnership with agency partners and community members
  • Construct new infrastructure

Phase 2 (2026 to 2030)

  • Plan, design, pre-construction of new infrastructure

In conversations with residents, there seems to be a drastic difference in the experience of living near Longfellow Creek before the 1960s versus after. Residents that lived here in the 1920s and 30s remember seeing minnows, crawdads, and salmon in Longfellow Creek. Heron, pheasants, and quail were common in the woods and around local water bodies. While there are still many animals like rabbits, geese, squirrels, and ducks living in these niches, the variety and number of species has declined.

As the Port developed in the area now known as Harbor Island, sections of the creek were piped and moved underground. By 1974 large sections of the creek were piped, including the vast majority of the creek’s headwaters.

Throughout the development of South Delridge in the 20th century, Longfellow Creek’s ecosystem was fundamentally altered. The creek now experiences flooding from an increase in hard surfaces and degraded water quality from untreated sewage (CSOs) and stormwater. Through the Longfellow Starts Here project and other projects in the Longfellow Creek basin, SPU aims to reduce CSOs, improve water quality in the creek, and help protect this critically important system.

Impacts to Longfellow Creek

Sewage and stormwater (runoff from roofs, streets, and sidewalks) from many older parts of the city, including areas within Delridge, combine into one network of pipes (a combined sewer system). In dry weather conditions, all flows in these pipes go to King County's wastewater treatment system as shown in this figure:

Graphical diagram shows wastewater path into a combined sewer during dry weather. From a house, sources include roof drains, storm drains, sinks, and toilets. Wastewater and sewage flows toward treatment plan, without overtopping into outfall pipes into waterways.

During the heaviest rainstorms, combined sewers can fill to capacity and the excess of that combined mixture of stormwater (90%) and sewage (10%) flows to the nearest water body instead of backing up into homes and streets. This is shown in this figure:

Graphical diagram shows wastewater path into a combined sewer during wet weather. From a house, sources include roof drains, storm drains, sinks, and toilets. Stormwater and sewage flows combine toward treatment plan, but overtop barriers and partially flows into outfall pipes and then into waterways.

In Delridge, the nearest water body is Longfellow Creek.

These combined sewer overflows, or CSOs, contain contaminants that can make people sick and harm fish, wildlife, and the environment. In some parts of the city, there are two pipe networks in the street: one to carry sewage (separated sewer systems) and another to carry stormwater runoff (the "drainage system"). Seattle's drainage system discharges stormwater directly to creeks, rivers, lakes, and Puget Sound.

Although there is no sewage in stormwater, it can still carry harmful contaminants from street runoff that can also make people sick and harm fish, wildlife, and the environment. In some parts of Delridge, there is a drainage system that discharges to Longfellow Creek.
In order to improve the water quality in the creek, we are looking for ways to reduce the amount of stormwater entering the creek during heavy rainstorms. We are also exploring how to make our combined sewer system and drainage systems more flexible and adaptable in response to changing weather patterns due to climate change.


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.