SE 4th Street Improvement Project

190712 SE 4th .jpg

Project Update:

July 12, 2019

Conduits for the joint utility trench have been placed and utility companies are now working on installing their equipment. Significant portions of the new underground system have been energized for power.  The communication companies are currently working on converting their systems. You can see in the photo above there is only one wire left on the utility poles.  In a few weeks that wire will be removed also along with the poles.  This will really open up the roadway for the contractor to work. 

Installation of the stormwater detention tanks is complete on the south side of the road and is beginning on the north side. Once overhead utilities are removed, construction can begin on the north side of the road.  There are nineteen large modular tanks to be installed.  The large tanks consist of more than 25,000 smaller tanks that can be stacked together to form various shapes and fit into tight places.  Once installed these systems will hold almost 600,000 gallons of rain water, about as much as an Olympic size swimming pool, and will be able to support heavy vehicle loads. 

228th Intersection Construction - work will begin in a few weeks near the 228th intersection to install a large stormwater detention tank and an eastbound right turn lane.  Most of this work is on SE 4th St and should have minimal impact to 228th Ave traffic.

The following is a summary of active work.

Joint Utility Trench - Utility companies are installing their equipment in the underground conduits.  This work could run through September, though crews are working on ways to coordinate work and expedite this construction during this phase and it is looking like overhead utilities could be removed as early as July.

Stormwater - Installation of the storm sewer and detention tanks will be ongoing through the Fall of this year. Current installation area is on the north side of the road between 222nd Pl and 225th Pl.

Roadway Grading - Grading for the concrete curb and gutter will begin near the end of July for the south side of the roadway.

Traffic Control - Hours of construction work are typically Monday to Friday 7:00am to 5:00pm. During these hours flaggers will be controlling traffic through the construction zone.  Depending on the construction work there will be times with significant travel delays.  Please plan accordingly and consider using alternate routes during hours of construction.  We recommend driving around the project during hours of work as travel delays due to construction activities will be ongoing and the roadway is quite rough due to all of the construction work.

Construction Schedule - The chart below shows the general anticipated timeline and progression of work.  There are many moving parts to the project and work activities may sometimes happen out of sequence due to the need to work around unforeseen issues that could not have been anticipated, e.g. hidden subsurface objects, locally varying soil conditions, weather, etc.

SE 4th Const Schedule.png
SE 4th St Pictures


The SE 4th Street Improvement Project is a critical component to support the City's Town Center plan. It will develop SE 4th St between 218th Ave SE and 228th Ave SE into a multi-modal corridor to meet concurrency requirements and provide increased opportunity for access and development within the core mixed-use area.

The existing road consists of two travel lanes with narrow shoulders and no sidewalk. The proposed road will be developed to include two travel lanes, a center turn lane or median, bike lanes, planter strips and sidewalk. This project will also coordinate the installation of upgraded Sammamish Plateau Water and Sewer District utilities with the roadway construction.

Project Exhibit - SE 4th Street - 218th to 228th - Roll Plot

Project Funding

The preliminary project estimate is $13,250,000. This includes cost for construction, engineering, and right-of-way. Cost to underground overhead utilities has not yet been determined.

Funding Source Amount
TIB Grant * $4,000,000
Traffic Impact Fees $6,909,900
Stormwater Capital Funds $1,500,000
Other Transportation Capital Funds $ 840,000
Total Project Funding $13,250,000

*In August of 2015, the City applied for a Transportation Improvement Board (TIB), Urban Arterial Program Grant to assist with funding this project. TIB selected this project for funding November 2015. As part of the grant requirement, funding for the project must be certified by November 20, 2016, and construction is expected to begin in 2017 or sooner.

SE 4th 2015 TIB UAP Application.pdf

Project Updates

On June 7, 2016 - the project team provided City Council with an update on the project design. City Council recommended that a public meeting be held prior to continuing with final design.

Agenda Bill - Agenda Bill 060716 SE 4th St Design Update.pdf

Exhibit 1 - Median Option Configuration

Exhibit 2 - Turn Lane Option Configuration

(Discussion begins at approximately 5:29 into the video.)

March 2, 2016 - The project design team is working through responses to both written and oral comments received during and after the open house meeting on January 28th. On February 9thth, staff briefed City Council on the project and on February 11th briefed the Transportation Committee on the project. (A copy of the PowerPoint presentation can be seen in the Resources section at the bottom of this webpage.) Staff is currently in the process of responding to these comments.

January 13, 2016 - the 30% plans have been developed. A pdf copy of the plan set can be downloaded by clicking on the hyperlink text below.

SE 4th St 30pct Plans Part 1 of 2

SE 4th St 30pct Plans Part 2 of 2

November 2016 Project Update

Project design is at 60 percent complete and has begun the right-of-way acquisition and environmental permitting processes. The following file is a copy of the draft Right-of-Way plans.

September 2017 Project Update

Project design is complete and ready to be advertised for construction. We are currently waiting for the US Army Corps of Engineers to complete an environmental permit review and working on the completion of a few remaining few remaining acquisitions for the necessary road right-of-way. Once these items are complete the project can be advertised for construction. We are anticipating that this will occur by November 2017.

February 2018 Project Update

Construction bids are currently being requested for the project. Bids are due to be opened on February 21st. 2018. Construction activities are anticipated to start mid-Spring of 2018 and go through Spring of 2020. Copies of the construction plans are available at Builders Exchange. The following is a link to the project page -

Public Utilities

Sammamish Plateau Water will be installing sanitary sewer along SE 4th St as part of this road improvement project. The proposed sewer extending to the north and south will be built separately as development occurs. A conceptual sewer plan has been developed by SPW. For additional information regarding the water and sanitary sewer utilities, please email SPW's project manager, Jackson Dove ( or call him at (425) 392-6256.


Project Design - December 2015 to June 2017
Project Permitting - December 2016 to present
Call for Bids - February 2018
Construction - April 2018 to May 2020

Public Involvement

2nd Project Open House - June 22, 2016 at City Hall Council Chambers (801 228th Ave SE) from 6 to 8 PM.

The main purpose of the meeting is to provide an update on the project and request feedback on the roadway cross section that will be constructed from 218th Ave SE to the west limit of the Town Center (approximately 222nd Ave SE).

Option 1 - Center Median.pdf
Option 2 - TWLTL.pdf
Option 3 - Hybrid.pdf
Meeting 2 Misc Exhibits.pdf

1st Project Open House - January 28, 2016 at Pine Lake Middle School from 6:00 pm to 7:30 pm. It will be in the Commons room, right across from the main office.

PLMS Address: 3200 228th Ave SE, Sammamish, WA 98075

Below are the exhibits that were shown at the January 28th meeting.

SE 4th St - Project Goals.pdf
SE 4th St - Project Schedule.pdf
SE 4th Street - 218th to 228th - Roadway and Typical Sections.pdf
SE 4th St - Mini-roundabout vs Traffic Circle.pdf
SE 4th - AutoTurn @ 220th.pdf
SE 4th St - Planting Options.pdf
SE 4th Town Center Conceptual Sewer.pdf

The following file is a compilation of the written public comments that were submitted for the January 28th Open House -
160128 Public Comments.pdf

If you would like to make additional comments regarding this project. Please click on the Comment Tab in the left menu.

Staff Contact