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Thornton Creek Confluence Updates

August 26

Construction Update

Seattle Public Utilities water crews will be conducting night work this Thursday, August 28th, in order to remove the remaining section of the old Thornton Creek culvert. Work is expected to last approximately three hours, starting around 10:00 p.m. Crews will access the construction site from the south and impacts could include additional construction vehicles and noise.

Additionally, the project has received an extension on the "fish window" period through the end of September. This will allow the contractor to continue in-water work, but will not impact the overall construction schedule.

August 18

  • Bridge formation continues on 35th Avenue NE.

Construction Update

The project reached a milestone earlier this week when the north branch of the creek was reconnected to the main stem, marking completion of in-water work on the north branch and main stem. This brings us one step closer to project completion and also means one less bypass pump running on the construction site. Over the next few weeks, construction activities will include:

  • Cleanup and dewatering of the site following heavy rainfall this week
  • Concrete pouring and formation of the bridge abutments
  • Creation of the south branch creek, west of 35th Avenue NE

August 11, 2014

  • The north branch of Thornton Creek during construction.

Construction Update

Construction of the culvert and meandering creek continues to progress. See below for near-term activities and an outline of the remaining construction timeline:

  • Excavation and placement of log structures in the north and south branches of Thornton Creek
  • Concrete pouring and formation of the bridge abutments
  • Connection of the north branch to the mainstem of Thornton Creek and Meadowbrook Pond

Construction is anticipated to be complete in the fall, with the following sequence of work:

  • Creek Restoration, continuing through September
    • Completion of in-water "fish window" work, with a possible extension through mid-September
    • Connection of south branch to the mainstem of Thornton Creek and Meadowbrook Pond
  • 35th Avenue NE, anticipated through the end of November
    • Complete the bridge, walls, sidewalks and barriers
    • Install utilities across the bridge
    • Form and pour the deck of the bridge; installation of water main on the bridge
    • Resurfacing, paving and striping of 35th Avenue NE
  • 36th Avenue NE, anticipated through the end of November
    • Install utilities along the floodplain
    • Construct the cul de sac
    • Construct the trail/roadway connecting 36th Avenue NE to Meadowbrook Pond
  • Site Restoration, anticipated through the end of November
    • Landscaping and planting
    • Fence installation
    • Artwork installation

July 25, 2014

Construction Update

It's been an unseasonably wet week for Seattle, including the Thornton Creek Confluence. The project area and creek were inundated with water following record-breaking rainfall over Seattle on Wednesday, but we are happy to report that crews should be able to draw down the water within a few days. Upcoming construction activities will include:

  • Clean up and restoration following this week's rainfall, which could include additional fish removal.
  • Saturday work will continue in order to complete in-water work within the fish window period. Crews can begin work as early as 9:00 am.
  • Concrete pouring to form the north and south walls of the culvert.
  • Stream channel construction east of 35th Avenue NE.

Please remember to support local businesses and public facilities \ during construction. These include the Meadowbrook Community Center and Pool, as well as Café Lati and Santorini Pizza and Pasta (both on the corner of 35th Ave NE and NE 110th Street).

July 11, 2014

  • Crews work on the footing installation of the new bridge over 35th Avenue NE

Upcoming Construction Activities

  • Crews will be working this Saturday, July 12 and subsequent Saturdays in order to complete in-water work within the fish window period of July and August. Crews can begin work as early as 9:00 am.
  • Excavation work and clearing will continue on both sides of 35th Avenue NE as the new stream channel starts to take form.
  • Concrete pouring and installation of the bridge footing and wall on 35th Avenue NE.

Important Reminders

  • Local businesses and public facilities are open during construction. These include the Meadowbrook Community Center and Pool, as well as Café Lati and Santorini Pizza and Pasta (both on the corner of 35th Ave NE and NE 110th Street).
  • Please remember that for your safety the construction zone is not open to the public. Children and adults should not enter the construction zone during or after construction hours.

Fish Removal Work

One important step in the project is moving the fish that have been swimming in the part of the creek where a larger channel will be created to protect them from the construction. Find out more

June 27, 2014

  • Crews work to install 35th Avenue NE bridge abutment

Upcoming Construction Activities

  • To prepare for the upcoming fish window period, crews will be on site this Saturday, June 28, during the normal hours of 9:00 a.m. to 6:00 p.m.
  • Fish removal and transportation will take place on July 1 and 2. The removal will be done by King County Department of Natural Resources and Seattle Public Utilities crews.
  • Removal of additional poplar trees west of 35th Avenue NE.
  • Crews will not work on the 4th of July holiday.

June 23, 2014

  • Demolition of 35th Avenue NE

Anticipated activities the week of June 23

  • Continued excavation work within the project area
  • Preparation for creek restoration work and the "fish window" period, scheduled to begin July 1

What's the "fish window?"

The fish window is a period of time when we can work in and around Seattle’s streams with reduced risk to fish and their habitat. It’s when fish – adults, juvenile, and eggs – are least likely to be present in the streambed or using it for spawning. The Washington Department of Fish and Wildlife determines the exact dates of the fish window for specific streams. For our project the window is July - August.

June 16, 2014

Anticipated activities the week of June 16

  • Removal of poplar trees on the south side of Thornton Creek west of 35th Avenue NE.
  • Demolition and excavation of 35th Avenue NE.
  • Continued excavation in the future floodplain area.
  • Expect noise, dust, vibration and truck traffic in the project area. Work hours for the project are 7:00 a.m. to 6:00 p.m. Monday - Saturday, with occasional work on Sundays.

Safety Reminder

  • Please remember that for your safety the construction zone is not open to the public. Children and adults should not enter the construction zone during or after construction hours.
  • Alteration or removal of traffic-control and detour signs is prohibited. Please do not move the detour signs that are in place.
  • The "local access only" section of 35th Avenue NE between NE 105th Street and NE 110th Street is an active construction zone during work hours. Pedestrian, bicycle and vehicle access needs to be limited to those that live there or are visiting the Meadowbrook Pool and Community Center.

June 6, 2014

  • Temporary driveway to Meadowbrook Community Center and Pool
  • Crews excavate and clear the future floodplain
  • Building a temporary bridge over the creek to move construction equipment
  • Thornton Creek: waiting for a new home

35th Avenue NE is now closed and the new temporary driveway to Meadowbrook Community Center is complete. We’d like to remind you that public facilities and local businesses are open during construction. These include the Meadowbrook Community Center and Pool, as well as Café Lati and Santorini Pizza and Pasta (both on the corner of 35th Ave NE and NE 110th Street).

Anticipated activities during the week of June 9

  • Glacier Drilling and Dewatering will drill and pump groundwater in the construction zone on 35th Ave NE to prepare for demolition of the current culvert.
  • Continued excavation and clearing of brush in the future floodplain area.
  • The contractor will not work on or west of 35th Ave NE June 12, 13, and 14 to allow Nathan Hale High School to enjoy their graduation celebration.
  • Some SPU water customers may experience a brief water outage. Customer service representatives will work directly with affected customers.
  • Expect noise, dust and truck traffic in the project area. Work hours for the project are 7:00 a.m. to 6:00 p.m. Monday – Saturday, with occasional work on Sundays.

Stay safe!

Please remember that for your safety the construction zone is not open to the public. Children and adults should not enter the construction zone during or after construction hours. Please also treat the “local access only” sections of 35th Ave NE between NE 105th Street and NE 110th Street as an active roadway for passenger and construction vehicles. These areas may seem quiet now, but construction traffic will increase in the coming weeks.

May 30, 2014

Closure of 35th Avenue NE

35th Ave Northeast, between Northeast 110th Street and Northeast 105th Street, will be closed to through traffic beginning Monday, June 2. It will remain closed for the duration of the project.

Traffic will be detoured from 35th Avenue Northeast to Lake City Way Northeast via Northeast 110th Street and Northeast 95th Street. Detour signs will be in place prior to the closure and Seattle Department of Transportation will be providing additional pedestrian safety measures, including speed limit signs on NE 110th Street.

Southbound Metro buses (Route 64 and 65) will be detoured to Lake City Way Northeast via Northeast 110th Street and Northeast 95th Street. Northbound Metro buses will be diverted to Sandpoint Way Northeast via Northeast 95th Street and Northeast 110th Street. Find out more information at King County Metro Alerts as the closure date approaches.

Anticipated activities during the week of June 1

  • Crews will begin to move machinery onto 35th Avenue NE.
  • Construction of a temporary north driveway to Meadowbrook Community Center. The south entrance and parking lot will remain open during and after construction of the new temporary driveway.
  • Fencing along the walkway between the community center and the creek to mark the pedestrian detour.
  • Expect noise, dust and truck traffic in the project area. Work hours for the project are 7:00 a.m. to 6:00 p.m. Monday – Saturday, with occasional work on Sundays.
  • Seattle City Light will turn off power to some residents in the project area Sunday, June 1 at 7:00am for approximately 3 hours. Affected residents should already have received a notice from Seattle City Light. If you received a notice and have additional questions please contact Patty Breidenbach at patty.breidenbach@seattle.gov or (206) 684-4795.

Anticipated activities during the week of May 26

  • Continued utility relocation on 35th Avenue NE
  • Continued excavation in Meadowbrook Pond
  • Closed Circuit Television monitoring of sewer pipes on 36th Avenue NE. This work will take place in the early morning hours. A representative from Westwater Construction will individually notify homes in the area to provide details.
  • Expect noise, dust and truck traffic in the project area. Work hours for the project are 7:00 a.m. to 6:00 p.m. Monday – Saturday, with occasional work on Sundays.

Looking Ahead

35th Ave Northeast, between Northeast 110th Street and Northeast 105th Street, will be closed to through traffic beginning Monday, June 2. It will remain closed for the duration of the project.

May 19, 2014

Anticipated activities the week of May 19

  • Utility relocation work will continue along 35th Avenue NE. Traffic impacts may include one-lane road closures
  • Tree removal within the SPU-owned property on 35th Ave NE
  • Mobilization of equipment and contractor crews continues near 36th Ave NE and Meadowbrook Pond
  • Expect increased noise, dust and truck traffic in the project area. Work hours for the project are 7:00 a.m. to 6:00 p.m. Monday – Saturday, with occasional work on Sundays

Closure of 35th Avenue NE

As many of you know, 35th Avenue NE at Thornton Creek will be closed to through traffic for the duration of construction. Closure is anticipated for late May and notification will be provided in advance of the closure, including notice of Metro bus re-routes. Meadowbrook Community Center and Pool will remain open and accessible from the south during construction.

May 13 drop-in session

The project team held a public drop-in session at the Meadowbrook Community Center on May 13. Thank you to the more than 75 people who attended for your continued engagement and interest in the project.

April 24, 2014

Construction for the Thornton Creek Confluence project begins soon. The project team at Seattle Public Utilities would like to invite you to an informal drop-in session.

Tuesday, May 13
5:30 – 7:00 p.m.
Meadowbrook Community Center
10517 35th Ave NE, Seattle, WA

We hope you will join us to:

  • Find out what to expect during construction
  • Learn about local impacts on traffic, Metro bus routes, and more
  • Chat one-on-one with the project team and construction company

For more information, or if you can’t make it to the drop-in session, please contact Jason Sharpley, Project Manager: jason.sharpley@seattle.gov or 206-615-0030.

View detailed information regarding road closures and bus route changes: Thornton Creek Confluence Construction Press Release – April 16, 2014.

April 4, 2014

Westwater Construction Company has been awarded the construction contract for the project. In April and May, the City will work with the contractor to develop the construction schedule and traffic control plan. Construction is anticipated to begin in early June, with crews mobilizing in mid to late May.

In April, you will continue to see preliminary construction work occurring. This includes minor water service work on 36th Ave NE. Those directly impacted by this work will receive notification from SPU identifying the day(s) and durations of the impact. Additional pre-construction work includes utility relocation along 35th Ave. N.E.

March 24, 2014

On April 1, the Thornton Creek Confluence project team will provide a project update to the Lake City Neighborhood Alliance. The meeting will be held at the Lamb of God Lutheran Church, 12509 27th Ave NE, Seattle, 98127 and will begin earlier than usual, starting at 6:30 p.m. For more information, please visit www.lcna-seattle.org.

March 14, 2014

Starting in April, pre-construction work for the Thornton Creek Confluence project will begin. As part of the preparation for full mobilization of construction crews by June 1, tree removal and utility relocation work will be underway in and around the Confluence project area. Work will occur during weekday, daytime hours. Details about each activity are below:

  • Tree removal – several trees in the project area will be removed to make way for the construction of the new, meandering creek. Approximately 108 trees, including up to 11 street trees on 35th Ave NE, will be removed prior to construction, and more than 600 new trees and 3800 shrubs will be planted as part of the project.
  • Utility relocation – SPU is working with other City departments and private utilities to relocate utilities necessary for construction.

January 24, 2014

Join us at the Thornton Creek Alliance meeting on January 30 to hear the latest design and pre-construction updates. The meeting will take place at the Meadowbrook Community Center (10517 35th Ave N.E.) from 7:15 to 9:00 p.m. For more information, please visit www.thornton-creek-alliance.org/.

November 4, 2013

The Thornton Creek Confluence project team will be at the November 14 Meadowbrook Community Council meeting to provide project design updates and answer questions from the community. The meeting is held at the Meadowbrook Community Center (10517 35th Ave N.E.) and will begin at 7:00 p.m.

September 26, 2013

The Washington State Environmental Policy Act (SEPA) Checklist and Determination of Non-Significance were issued on September 26, 2013. The proposed Thornton Creek Confluence project addresses the undersized culvert on 35th Ave NE, local urban flooding, and improved in-stream habitat and water quality. The environmental impacts of the proposed project have been analyzed and SPU has issued a Determination of Non-Significance:

SEPA Checklist (pdf)
Determination of Non-Significance (pdf)

December 21, 2012

Notes from November 14th Community Meeting (pdf)
November 14th Presentation (pdf)

November 8, 2012

Community Meeting

Wednesday, November 14th - 6:00 to 7:30 p.m.
Nathan Hale High School "Commons"
10730 30th Ave. NE

September 10, 2012

SPU received many comments from the public regarding the 60% design of the Thornton Creek Confluence Improvement project throughout August. View a compilation of those questions and comments (pdf).

Thank you to all who took the time to provide feedback – it is greatly appreciated! SPU will be evaluating these comments in September and deciding if and how to incorporate suggestions into the next stage of design, given the primary goals of the project are to reduce flooding and improve Thornton Creek’s natural habitat.

August 7, 2012

A meeting was held at the Meadowbrook Community Center on August 2nd to present the 60% designs for the Confluence project. View the presentation (pdf).

Some parts of the design are already fixed. These include the location and size of the new culvert to go under 35th Ave. N.E. and the stream channel, a design based on stream flows, scientific hydraulic properties, fish passage regulations and other factors.

All comments are welcome, but SPU would like input on these particular areas by August 31:

  • To improve habitat and create more flood storage, we need to remove about 13 poplar trees west of 35th Ave. N.E. Is this an acceptable trade-off?
  • The existing gravel lot at the end of 36th Ave. N.E. will go away. Should another gravel area be provided for parking along 36th?
  • Culvert replacement under 35th Ave. N.E. will require 3 to 7 weeks of construction, depending on full versus partial road closure. This will impact travel on 35th. Do you prefer a full road closure and shorter duration (3-4 weeks)?
  • In order to maximize flood storage, the plans currently have no paths through the site and show removal of the existing footbridge near the 36th Ave. N.E. street end. Is there a preference for allowing some limited pedestrian access versus keeping the area natural?
  • Would an overlook from the 35th Ave. N.E. sidewalk be preferred in place of a path through the site or in addition to?

July 20, 2012

Community Meeting

Thursday, August 2 - 7:30 to 8:30 p.m.
Meadowbrook Community Center
10517 35th Ave. NE

Question & Answer Session

Saturday, August 4 - 10 a.m. to noon
Confluence Project Site
10720 35th Ave. NE (Approximate location)

Both sessions are for SPU to present the 60% designs for the Confluence project and to solicit input, suggestions and public concerns about the work. A design overview and full set of 60% design drawings are posted below. We would like to have feedback on what you see, though some items – such as the 35th Ave NE culvert location and size and the stream channel dimensions and location – are fixed due to hydraulics and site constraints. All comments are welcome but particular areas we’d like feedback on are:

  • To improve habitat and create flood storage west of 35th, we need to remove approximately 13 poplar trees on the west side of 35th. Is this an acceptable trade-off?
  • The gravel area at the south dead end of 36th Ave NE will go away. Should another gravel area be provided for parking on the east side of 36th?
  • Culvert replacement under 35th Ave NE will require 3-7 weeks of construction, depending on full closure versus partial street closure. This will impact travel and potentially reduce bus service on 35th. Or would you prefer a full road closure and shorter duration (3-4 weeks)?
  • In order to maximize flood storage, the plans currently have no paths through the site and show removal of the existing footbridge near the 36th Ave NE street end. Is there a preference for allowing some limited pedestrian access versus keeping the area natural?
  • Would an overlook from the 35th Ave NE sidewalk be preferred in place of a path through the site or in addition to?

Frequently Asked Questions (pdf)