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

Members of the project team conducted the first field-investigation portion of the project on January 12th, 2018.  Field work consisted of walking the channel of Zackuse Creek from its mouth at Lake Sammamish to its headwaters up-basin, studying tributary channels in the basin, and taking a tour of known storm and surface water problem areas within the Tamarack and other neighborhoods. 

Our first public meeting was held at City Hall on January 24th, 2018. The meeting 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. 

If you would like to provide your input on drainage problem areas, or share with us your opinion of criteria we should use to prioritize which projects get budgeted, please complete the survey at this link:

Timeline (Updated 30 April, 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

Summer/Fall 2018 - Community Event Focus Meeting

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