Pearl Street Drainage Improvement Project

Image map of Pearl Street project location.
The City will make drainage improvements in west Beacon Hill.

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 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 project involves:

  • 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 technology (i.e. no excavation for pipe installation) and installing a maintenance hole at the S Bennett street end
  • Building a large underground storage tank to capture sewage and stormwater during large storm events and then slowly release it into the pipes that run under S Dawson St
  • Constructing a small facility building on the south side of the intersection of Corson Ave S and S Dawson St (view Facility Building Design)
  • Installing three aboveground electrical cabinets on the north side of S Dawson St


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

What's Happening Now?

Construction began in late June 2020, and it will take about 16-18 months to complete this project.

Early construction activities include:

  • Replacement of the sewer pipe on Corson Ave S. This work will be done in phases starting from S Dawson St and working north to S Ferdinand St. This work is expected to take 4 months to complete.
  • Seattle City Light (SCL) installing a temporary service at the entrance to the alley on the north side of S Dawson St in preparation for the work on S Dawson St. During this work, there will be a brief, temporary service disruption. SCL will provide notice to impacted residents.
  • Paving the east/west section of the alley between S Dawson St and S Bennett St. Residents adjacent to this work have received additional notification about impacts.

Once these activities are complete, the contractor will begin construction work on S Dawson St. This phase of the project will last about 1 year, and it will require a 24 hr/day full road closure and no parking on S Dawson St between Corson and 12th avenues. Additional notice will be provided prior to this phase of work. 

Learn more about what to expect during construction by reviewing the Construction Phase Overview, and Construction Phase Map and signup to receive project email updates.

Anticipated Impacts

You can expect:

  • Construction noise, dirt, dust, and vibrations
  • Crews to work 8 to 10 hour days Monday through Friday. Work hours and days may vary based on work being preformed. Evening or weekend work may be required later in construction, advanced notice will be provided.
  • Increased construction traffic and staging of large equipment in the area
  • Work will typically occur during weekday, daytime hours, but some night and weekend work may be required. Additional notice will be provided via the project email list prior to night or weekend work.
  • Temporary, short-term service interruptions to gas, water, and electricity to connect to new services. Impacted residents will be notified prior to this work.
  • Lane closures and parking restrictions along Corson Ave S for sewer pipe installation.
  • 24 hr/day full road closure and no parking on S Dawson St between Corson and 12th avenues for approximately 1 year. Additional notice will be provided prior to this phase of work.
  • Short-term driveway access and street parking restrictions at the street end of S Bennett St for maintenance hole installation and installation of new pipe using trenchless technology.
  • 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. Additional notification will be provided prior to this work.

Community Engagement

Please subscribe to the project email list to receive up-to-date information prior to and during construction.


Early 2018 to Late 2019

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

Early 2020

  • Finalize project design and prepare for construction
  • Provide project and construction-related updates
  • Pre-construction activities including Puget Sound Energy gas line relocation

Mid 2020

  • Construction began in late June 2020, and it is expected to take about 16-18 months. 

For more information about construction phases, please check out the Construction Phase Map.

Late 2021

  • Project Completion

Note, start date and duration of construction activities are subject to change. Residents will receive additional information about the schedule if schedule changes become necessary.