Stormwater Code and Manual Update 2026 - Background
Background
The Department of Ecology requires that Seattle updates our current codes with additional stormwater control regulations as a condition of our 2024 National Pollutant Discharge Elimination System (NPDES) Phase 1 Municipal Stormwater Permit (Ecology NPDES Permit). To meet these requirements, we are revising our existing Stormwater Code (SMC 22.800-22.808) and the associated Stormwater Manual (Directors' Rule 10-2021). These new rules will replace the current drainage control code and Directors' Rules which are administered jointly by SDCI and SPU.