Pearl Street Drainage Improvement

Project Description

Reducing stormwater flooding and backups in your neighborhood
Seattle Public Utilities is working on a capital improvement project to upgrade the combined sewer infrastructure in Seattle’s west Beacon Hill neighborhood.
The goal of the Pearl Street Drainage Improvement Project is to reduce storm-related sewer backups and flooding in the area, which will help protect public health and the environment as well as improve service reliability.
This improvement project will involve:

  • Installing a new sewer pipe along Corson Ave S from S Ferdinand to S Dawson streets
  • Expanding existing pipe between S Dawson and S Bennett streets using trenchless drilling
  • Building a large underground storage tank to capture sewage and stormwater during large storm events and then slowly release it into the pipes along S Dawson St
  • Constructing a small facility building on the south side of the intersection of Corson Ave S and S Dawson St
  • Installing aboveground electrical cabinets on the north side of S Dawson St


This project is located in west Beacon Hill with work occurring Corson Ave S from S Ferdinand to S Bennett streets, the street end of S Bennet St, and on S Dawson St between Corson Ave S and 12th Ave S. Most of the work will occur on S Dawson St.

What's Happening Now?

The Project Team completed design and is preparing for construction to start in spring 2020. 
SPU is reaching out to nearby residents to share project updates and potential construction impacts prior to construction. In the meantime, please review the Project Fact Sheet for more information about the project.

Anticipated Impacts

You can expect:

  • Construction noise, dirt, dust, and vibrations
  • Increased construction traffic and staging of large equipment in the area
  • Lane closures and parking restrictions along Corson Ave S for sewer pipe installation
  • 24/7 full road closure and no parking on S Dawson St between Corson and 12th avenues for approximately 1 year to install the storage tank and perform other work. SPU contractor will perform improvements to the alley between S Dawson and S Bennett streets prior to closure.
  • Short-term driveway access and street parking restrictions at the street end of S Bennett St
  • Work will typically occur during weekday, daytime hours, but some night and weekend work may be required
  • Temporary, short-term service interruptions to gas, water, and electricity to connect to new services. Impacted residents will be notified prior to this work.
  • Entrance to the alley on the north side of S Dawson will be blocked during construction for temporary Seattle City Light service. Residence will continue to have alley access via Pearl St.
  • The contractor will coordinate mail delivery and garbage/recycling/compost pick-up to avoid service disruptions. Please contact the project team if you experience any service disruptions.
  • The contractor will provide access to emergency services, as needed, during construction
  • Site restoration, which may involve 24/7 road closures for repaving work

Community Engagement

Join us for a drop-in session on Saturday, April 4 anytime between 10 a.m. and 12 p.m. at the corner of Corson Ave S and S Dawson St to learn more about the project and get information about construction.
Please subscribe to the project email list to receive up-to-date information throughout construction.


Early 2018 to Late 2019

Project team working on design and permitting
Shared updates with nearby residents

Early to Mid-2020

  • Finalize project design and prepare for construction
  • Provide project and construction-related updates
  • Pre-construction activities including Puget Sound Energy and Seattle City Light work to begin as early as April 2020
  • Construction scheduled to begin. Once started, work is expected to take about 16-18 months.

Late 2021

  • Project Completion

Note: permitting, weather, and other factors may impact the start date and duration.