Issaquah Master Drainage Plan Issaquah, Washington

With goals to improve public safety, reduce maintenance frequency, increase drainage system reliability, restore aquatic and riparian habitat, and improve water quality, the City of Issaquah sought to develop a surface and stormwater master plan (SSWMP). Working closely with the city, Otak developed the plan to establish a foundation for future infrastructure enhancements.

Guidance for Future Infrastructure Improvements

The plan develops a prioritized list of stormwater infrastructure and habitat restoration projects to be implemented within a 20-year timeframe, simultaneously helping the city many its grown while remaining compliant with NPDES permitting. It provides guidance for subsequent projects that would address the impacts of impaired surface water quality, aquatic and riparian habitat degradation, increased flooding, and aging infrastructure.