Seattle On-Site Stormwater requirement

The code mandates minimum requirements for on-site stormwater management for development projects. It requires developers to manage runoff within their site boundaries, reducing the volume and pollution entering the city’s stormwater system through Best Management Practices (BMPs) like rain gardens, bioretention, trees and permeable pavements. This section, supplemented by stormwater manuals, ensures projects minimize their environmental impact and comply with city regulations for development permits.