30th Ave NE Sidewalk & Natural Drainage System

 This project is complete!

Project Overview

Phase One: NE 130th St to NE 137th St

In the spring of 2019 the Seattle Department of Transportation (SDOT) and Seattle Public Utilities (SPU) completed the first phase of new sidewalks and a Natural Drainage System (NDS) along the east side of 30th Ave NE between NE 130th St and NE 137th, making it safer, easier, and more pleasant to walk along 30th Ave NE. The NDS helps capture and treat polluted stormwater runoff before it reaches Thornton Creek, which improves water quality and reduces pollution in Lake Washington. The NDS was designed, constructed, and will be maintained by SPU.

This project was selected as part of our Sidewalk Development Program and as part of SPU’s Integrated Plan to treat polluted stormwater within Thornton Creek Basin. The project captures efficiencies in design and construction, and fosters improved coordination between City departments and their individual projects.

Image showing 30th Ave NE condition before phase 1 installation of sidewalk and Natural Drainage System.Image showing 30th Ave NE condition after phase 1 installation of sidewalk and Natural Drainage System.
Before and after sidewalk construction along 30th Ave NE 

Phase Two: NE 137th St to NE 143rd St

We heard from neighbors during early outreach that the new sidewalks completed in Phase One should be extended north towards N 145th St and we are now making those improvements as a part of Phase Two. To begin creating a clear walking path along 30th Ave NE, we have completed interim improvements between NE 137th and NE 143rd St. The improvements included new gravel, vegetation clearing, and parking restrictions. Full concrete sidewalks will be constructed next as the final part of this work. Natural Drainage Systems will not be a part of Phase Two.

Before and after sidewalk construction along 30th Ave NE
Existing gravel shoulder where we'll build the new sidewalk 

Natural Drainage Systems

Natural drainage systems (NDS) are a type of green stormwater infrastructure system (GSI) built to capture runoff and filter pollutants. An NDS uses specialized plant species and soils to filter stormwater runoff and pollutants. Plants are selected to help the NDS do its job: clean stormwater and allow it to slowly seep into the ground.

You can view the plants selected for the NDS on 30th in our “planting palette” located in the materials section of this page.

The image below shows an example cross section of the new sidewalk and natural drainage system. The project design may include elements shown in the cross section and varies by location.

Natural drainage system example

Project map

Click to enlarge map


June 2020 - early 2021

Phase two of sidewalk construction

July - October 2018

Phase one of corridor wide improvements

January 2018

Designs completed

Completed designs shared with community

September 2017

Begin working with residents about property impacts

July 2017

Designs shared with Lake City Way Neighborhood Alliance

March 2017 - Spring 2018

Finalize project design, community feedback and engagement

March 2017

Early outreach begins

Project Budget & Funding

This project is a partnership between SDOT and SPU.

SDOT funding is through our Sidewalk Development Program, with funds from the Levy to Move Seattle. The 9-year $930 million Levy to Move Seattle was approved by voters in 2015.

SPU funds are from the NDS Partnering Program, which is part of the Plan to Protect Seattle's Waterways and uses NDS to improve water quality in large creek watersheds.



Greg Spotts, Director
Address: 700 5th Ave, Suite 3800, Seattle, WA, 98104
Mailing Address: PO Box 34996, Seattle, WA, 98124-4996
Phone: (206) 684-7623

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The Seattle Department of Transportation (SDOT) is on a mission to deliver a transportation system that provides safe and affordable access to places and opportunities for everyone as we work to achieve our vision of Seattle as a thriving, equitable community powered by dependable transportation.