Zackuse Basin Plan

Project Updates

June 10, 2019

The FINAL Zackuse Basin Plan has been completed and posted.  We provided a Resolution to adopt the Zackuse Basin Plan to the Sammamish City Council at the June 18th, 2019 Regular Meeting.

Project Description

About Zackuse Creek Basin and the Tamarack Neighborhood

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.

Project Purpose

The purpose of this project is to develop a basin plan for the Zackuse Creek basin. Having a basin plan will aid the City in identifying and prioritizing short and long term actions to improve the overall health of the basin.

The plan will evaluate flooding, erosion, water quality, and fish and wildlife habitat problems in the basin. Problems will be looked at under existing and future predicted conditions.

The plan will also include recommendations, prioritization and planning level cost estimates. Costs will be estimated for capital improvement projects (CIP), maintenance and operations activities, and programmatic measures to correct, mitigate, or avoid these problems.

Timeline 

Updated June 10, 2019

Presentation Materials

• Public Meeting Presentation January 2018
• Zackuse Basin Map (LiDAR) for Presentation #1
• Zackuse Basin Map (Aerial) for Presentation #1
• Public Meeting Presentation August 2018