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Thornton Creek Confluence Updates

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)