Louis Thompson Tightline
What's happening now
The City of Sammamish will start this summer the construction of the improvements to Louis Thompson Road from 210th Place Southeast to Eastlake Sammamish Parkway Northeast that will upgrade the existing stormwater conveyance, culvert, and ditch systems in the area and alleviate the flooding, erosion, and landslide issues.
Join us for a virtual open house on Wednesday, Aug. 7, to learn more about the upcoming project construction and ask the project team questions. This event will be held online via Zoom.
Event details
- Wednesday, Aug. 7, from 6 to 7 p.m.
- Register here: bit.ly/louis-thompson-tightline
Project Status
Following community feedback and preferences expressed previously, the City of Sammamish City Council approved the implementation of proposed alternative #4 in September 2022. Planned improvements include:
- Upgrades to existing stormwater conveyance, culvert, and ditch systems in the area to alleviate flooding, erosion, and landslide issues.
- A new sidewalk and bike lane on the north (downhill) side of the road to improve safety and connectivity to adjacent neighborhoods.
- A 6-inch paint line and widened 6-foot shoulder on the south (uphill) side to improve safety along the road.
We look forward to providing further details about the project and answering any questions you may have.
Project Background
Louis Thompson Road is a vital connection route serving residents of Sammamish and surrounding communities. Historically, the corridor has been impacted by uncontrolled stormwater runoff.
The City's project team is designing improvements to Louis Thompson Road from 210th Pl SE to Eastlake Sammamish Parkway NE that will upgrade the existing stormwater conveyance, culvert, and ditch systems in the area and alleviate the flooding, erosion, and landslide issues.
Project Area Today
Project Needs and Goals
Controlling stormwater runoff and erosion
Uncontrolled stormwater runoff from the existing roadway and surrounding private properties results in erosion of the existing ditches and at culvert outfalls. Upgrades in the stormwater collection and conveyance system will be implemented to improve conditions and reduce the frequency of flooding events, erosion, and possibility of landslides.
Adding a sidewalk and bike lane
The corridor does not currently include any sidewalks, bike lanes, or other non-motorized improvements. While the project’s primary goal is to address the stormwater runoff issues, the City will also be adding non-motorized improvements, including a sidewalk and bike lane to connect adjacent neighborhoods with Lake Sammamish.
Protecting streams and wetlands
These improvements will be coupled with the City’s commitment to protecting environmentally sensitive areas, such as stream crossings and wetlands. The City will work with the community and appropriate agencies to ensure that roadway improvements are made without negatively impacting natural areas and areas which serve as important habitat for fish and wildlife.
Project Design
This project will upgrade the existing stormwater conveyance, culvert, and ditch systems in the area and alleviate the flooding, erosion, and landslide issues. New sidewalk and bike lane will improve safety.
Selected alternative
The preferred alternative - selected by City Council in September 2022 and informed by community input earlier this year – will include a sidewalk and bike lane on the north (downhill) side of the road, as well as a 6-in paint line on the south (uphill) side of the road. The south (uphill) side of the road will also be locally widened to provide a five-foot wide shoulder throughout the project area.
Project location
These improvements will be built from 210th Pl SE to Eastlake Sammamish Parkway NE. See the cross-section and map below for more details.
Outreach and Community Engagement
October 2022 - Virtual Open House
Thanks to everyone who attended our Virtual Open House on Thursday, October 27. A recording of the presentation and Q&A is available below. You can also view the slideshow.
May 2022 - Virtual Public Meeting
Thank you to everyone who attended our May 5 Virtual Public Meeting. If you were not able to make it, you can view a recording of the presentation and Q&A below. You can also view the slideshow.
- The City is planning to engage the public throughout the design process to gather community input on proposed improvements and build trusting relationships with stakeholders.
- The City is committed to a clear and transparent design process to ensure the final design reflects the preferences of the community and meets their current and future needs.
- The City's project team is available to meet virtually with interested community organizations, schools, businesses, property owners, and residents to share more about the project and better understand concerns, priorities for design, and how they would like to communicate with the City and share input throughout the project.
The health and safety of the greater Sammamish community will be the forefront priority when planning and executing outreach related to this project. The project team expects to prioritize virtual and digital engagement opportunities for the foreseeable future.
Grant funding partners
- King County Flood Control District - Flood Reduction Grant: $400,000
- King County Flood Control District - Sub-Regional Opportunity Grant: $192,942
- Department of Commerce - State and Local Fiscal Recovery Funds: $3,000,000
