30th Ave NE Sidewalk & Natural Drainage System

Updated: January 6, 2020

What’s Happening Now?

Design of the 30th Ave NE sidewalk project phase two, between NE 13th St and NE 143rd St is complete! Construction may begin as early as spring 2020.

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Project Overview

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

The Seattle Department of Transportation (SDOT) and Seattle Public Utilities (SPU) completed construction of new sidewalks and a Natural Drainage System (NDS) along the east side of 30th Ave NE between NE 130th St and NE 137th St in spring 2019. This project makes it safer, easier, and more pleasant to walk along 30th Ave NE. The NDS will help 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.

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

During early outreach, we heard from neighbors that the new sidewalks on 30th Ave NE should be extended to reach NE 145th St. We're excited to announce that we're planning to extend the sidewalks to the north. The plans extend the sidewalk, but no Natural Drainage system, from 137th Ave NE to 143rd Ave NE. The sidewalk will tie in with the new sidewalk at NE 137th St and a future privately-built sidewalk between NE 143rd St and NE 145th St. The design was completed in late 2019 with construction in 2020.

We have completed an interim improvement in 2019 to create a clear walking path along 30th Ave NE between NE 137th and NE 143rd St. The improvements included new gravel, vegetation clearing, and parking restrictions. Full concrete sidewalks will be constructed as soon as sping 2020.This project is part of several improvements on 30th Ave NE. Our Arterial Major Maintenance will be repaving 30th Ave NE from NE 130th St to NE 135th St after the completion of the sidewalk and NDS on 30th from 130th to 137th. We are currently working with project area residents regarding specific property impacts. Additional project activities may include outreach in your neighborhood to answer questions, provide information about the project, and provide construction updates.

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.

The NDS on 30th will be built between the sidewalk and street where there may otherwise be a grass planting strip. 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 Design

This project will build a new sidewalk along the east side of 30th Ave NE between NE 130th St and NE 143rd St. The project will be constructed in segments and will incorporate new sidewalk infrastructure such as, retaining walls, new curb ramps and Natural Drainage Systems (NDS) located adjacent to the new sidewalk.

What will happen to existing trees in the right of way?

The planned improvements in the public right-of-way will affect some trees. Trees are important to reduce stormwater pollution and will be preserved where possible. A licensed landscape architect conducted a full tree assessment on all blocks to determine which trees should be protected and which may be replaced or transplanted. It is a priority to retain and protect trees throughout the project area. Any tree removed will be replaced with two young trees in the project area, however, not necessarily in the same specific locations as the removed trees. SPU will also prune trees or shrubs located in the natural drainage system as needed. SDOT will maintain any new trees for two years after they are planted. After that time, homeowners are responsible for tree upkeep.

Who will be responsible for the maintenance of the natural drainage system?

SPU is responsible for the watering, weeding, and general upkeep of the natural drainage systems to ensure proper function. Residents are not required to pay for or perform any maintenance. In fact, it is important for residents to stay out of the natural drainage system areas to maintain their function.

What kind of plants will I see?

The project team selects plants that help the natural drainage system do its job: clean stormwater and allow it to slowly seep into the ground. We also select plants that are easy to maintain and able to withstand wet winters and dry summers. The plants we'll be using are shown in our planting palette, also located in the materials section at the bottom of this page.

Will this project cause me to lose parking in front of my house?

We understand parking is very important to residents and we conducted a parking study at multiple times of day to assess parking availability and use on 30th. We’ll remove on-street parking from the east side of 30th and there will be no changes to parking on private property; existing driveways will remain at their current location.

Will transit lines be impacted?

The bus stop at NE 133rd St will be removed and we’re working with King County Metro to determine impacts to Routes 64 & 65 during construction. Metro will send out notifications regarding route changes and closures – learn more about specific changes and impacts to Route 64 and Route 65 on King County Metro’s webpage.

Project Map

Project map

Click to enlarge map

Outreach & Schedule

Design for phase two of this project was completed in late 2019, and construction is expected to begin in spring 2020.

July - October 2018

Implement corridor wide improvements

January 2018

Desings 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.