Zackuse Basin Plan


Project Description

The Zackuse Creek basin drains approximately 240 acres in the west portion of the City of Sammamish. The primary overland drainage conveyance in the basin is Zackuse Creek, which drains to Lake Sammamish and is located just south of and parallel to Louis Thompson Road in the City of Sammamish. Stormwater runoff from developed neighborhoods flows into Zackuse Creek via numerous culverts, ditches and outfalls along Louis Thompson Road. Although there are some undeveloped parcels in the Tamarack neighborhood, the basin is mostly fully developed and the neighborhoods would generally be classified as mature suburban neighborhoods.

The historic Tamarack neighborhood is somewhat unique to the City; roads are private and there is no public stormwater infrastructure. Stormwater runoff flows uncontrolled over land or in ditch-and-culvert systems west and south through the neighborhood, causing erosion and flooding issues. Non-attenuated flows from Tamarack and other basin neighborhoods may contribute to elevated peak flows in Zackuse Creek, causing erosion and landslide concerns in the creek ravine itself.

The purpose of this project is to develop a basin plan for the Zackuse Creek basin that will aid the City in identifying and prioritizing short and long term actions to improve the overall health of the basin. The plan will include evaluation of flooding, erosion, water quality, and fish and wildlife habitat problems in the basin under existing and future predicted conditions. The plan will also include recommendations, prioritization and planning level cost estimates of capital improvement projects (CIP), maintenance and operations activities, and programmatic measures including education and outreach to correct, mitigate, or avoid these problems.  

Project Updates

Our first public meeting was held at City Hall on January 24th, 2018, and at the Eden Glen HOA on January 31st, 2018. The meetings consisted of an informational session on basin planning and the Zackuse Basin Plan project in particular.  The presentation materials are posted on this webpage. Additionally, information on drainage problems - clarification and details of known problems as well as identification of new problems was shared by residents with the project staff. 

The City and Consultant team spent the Spring consolidating the drainage issues identified by residents and through our field work, and developing preliminary programmatic and capital activities that could address the issues.

The City is now hosting a second public meeting on Wednesday, August 1st, from 6pm to 8pm at City Hall. The City and Consultant team will briefly introduce the Plan, share the list of the Basin’s drainage issues, present the preliminary recommended activities and projects that have been identified from the Plan, and discuss the next steps forward.

Timeline (Updated 3 July, 2018)

Fall 2017 - Project Kick-off

Winter 2018 - Data Review & Field Evaluation

January 24, 2018 - Public Meeting #1 at City Hall

January 31, 2018 - Eden Glen HOA Meeting in Neighborhood

June 12, 2018 - City Council Meeting - Presentation and Acceptance of Prioritization Criteria 

Spring/Summer 2018 - Project and Strategy Development

August 1, 2018 - Public Meeting #2 at City Hall

Fall 2018 - Basin Plan Report Writing

December 2018 - February 2019 - Present Plan to City Council for Adoption


The fee for this project is $178,000.


Links to Pertinent Projects

Other City Basin Plans

Staff Contact