Storm and Surface Water Master Plan

Creek, Stream, Trees


Issaquah is developing a storm and surface water master plan (SSWMP), which is intended to be a planning document which will describe a prioritized set of planned investments in future drainage infrastructure and riparian and stream habitat restoration.  The goal is to protect and enhance the water quality and habitat of local creeks, Lake Sammamish and Puget Sound.


Previously, the City completed the Stormwater Management Plan in 2002, and a Stream and Riparian Areas Restoration Plan was completed in 2006. Issaquah has seen significant growth since these plans were developed and impacts of regional stormwater runoff on Puget Sound and other waters are becoming more apparent. 

The SSWMP will provide an analysis of the existing conditions of the City’s streams and drainage infrastructure within its various watersheds and provide a prioritized list of projects that will address water quality, riparian and stream habitat restoration, and localized flooding. To help the City meet these goals, the Washington State Department of Ecology awarded the City a grant which is supporting a portion of the development of the SSWMP.

Current Status

In January 2020, the City conducted a survey to gather public feedback to identify existing flooding, water quality, and habitat issues across the entire City.

As of late May 2020, the Basin Baseline Conditions Assessment for Issaquah Creek and its tributaries has been completed. This assessment evaluates existing conditions, including water quality, habitat, and fish use.  

The Baseline Condition Assessments for the other five watersheds – Laughing Jacobs, Parkhill, Tibbetts (and its tributaries), Schneider and Lewis Creek – are being completed.

The City is also completing a preliminary analysis of possible upgrades in the Olde Town neighborhood. 


Further work on the SSWMP is suspended due to the reduced ability for community outreach and feedback because of the ongoing COVID-19 crisis. 

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