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.
The actual code and manual changes are still to be determined. However, our regulations must be equivalent to the Ecology Permit.