Longfellow Starts Here

Photo of woods area with a footbridge

Project Description

Seattle Public Utilities is working to improve the sewer system in 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 resulting in Combined Sewage Overflows (CSOs) where the sewer system discharges untreated sewage into Longfellow Creek.

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

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

To reduce CSOs, improve water quality in Longfellow Creek, and provide amenities 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 and its 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 do things differently by moving away from the way utility management and urban planning has traditionally been done.

Usually the work plan for such projects does not allow enough time for the communities it affects to understand it and respond with what they want and need. Instead, this project is hoping to work with communities from the beginning, so that we can create a plan together that respects and enhances the way that communities use this space. In this journey we hope to combine our expertise, knowledge and vision 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, and multicultural, and /or 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 limit east to west connectivity. Many areas also lack safe sidewalks and bike lanes, and as well as experience flooding and drainage issues. The South Delridge community (South Delridge, Roxhill, Westwood, Highland Park, Riverview, and Puget Ridge neighborhoods).

Map image with border overlay

Visit the project area map

What's Happening Now?

The project team is partnering with an Innovation Team of community co-creators to guide and collaborate with the project team during this early planning phase. In the coming months, there will be more opportunities for community members that live, work, and/or engage in the South Delridge community to help us shape this work.

Upcoming Online Open House Engagement

In the coming weeks we will share a video and ask for input from the South Delridge community on how you can participate on the design for this website. We want the online open house to become a community hub where you can share your stories with us and for us to share project information and engagement opportunities with you. We cannot start this process without you and we look forward to learning what you want to see in your community.

Sign up for project updates and we will keep you posted.

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 seek partnerships with community members, schools, and other community organizations in the area. We are actively seeking ways to incorporate environment 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.

Also, check back here for more information about ways to be involved.

Innovation Team

An Innovation 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 needs around mobility, open space, etc.
    • Other community driven dreams and needs
  • 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 water 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


Historically, the South Delridge ecosystems have been home to a wide variety of wildlife. Residents that lived here in the 1920s and 30s remember seeing minnows, crawdads and salmon in Longfellow Creek and herons, pheasants and quails 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. In conversations with residents there seems to be a drastic difference in the experience of living near Longfellow Creek before the 1960s versus after. As the Port developed in the area now known as Harbor Island the creek was piped and moved underground and by 1974 large sections of the creek was 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 to experience flooding from an increase in hard surfaces and degraded water quality from untreated sewage (CSOs) and stormwater. While improvements to SPU’s sewer and drainage system have reversed some of that degradation, there is still work to do to 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 (shown below).

Depicts the flow of sewer in dry weather, described in page text

During the heaviest rainstorms (shown below), combined sewers can fill to capacity and any excess of that combined mixture of stormwater (90%) and sewage (10%) can overflow to the nearest water body to prevent sewage from backing up into homes and streets.

Depicts sewer flow when in heavy rain situations, as described in page text.

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 still can carry harmful contaminants such as 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 water entering the creek during heavy rainstorms and how to make our combined sewer system and drainage systems more flexible and adaptable in response to changing weather patterns due to climate change.