An ordinance relating to the 2026 Stormwater Code Update; updating stormwater control requirements for development, roadways, utilities, and maintenance activities; strengthening stormwater treatment and infiltration standards; clarifying vesting and review thresholds; ensuring the City’s compliance with requirements of the City’s 2024-2029 Phase 1 Municipal Stormwater Permit issued by the State Department of Ecology; and amending Chapters 22.800, 22.801, 22.802, 22.803, 22.805, and 22.807 of the Seattle Municipal Code.

CB 121190 · Ordinance (Ord) · Passed

Sponsors: Joy Hollingsworth

Timeline

• Mar 18, 2026: Mayor's leg transmitted to Council (Mayor)
• Mar 18, 2026: sent for review (City Clerk)
• Mar 20, 2026: sent for review (Council President's Office)
• Mar 31, 2026: referred (City Council)
• Apr 9, 2026: discussed (Governance and Utilities Committee)
• May 14, 2026: pass as amended (Governance and Utilities Committee)
• Jun 2, 2026: passed as amended (City Council)
• Jun 4, 2026: submitted for Mayor's signature (City Clerk)
• Jun 4, 2026: Signed (Mayor)
• Jun 4, 2026: returned (Mayor)
• Jun 4, 2026: attested by City Clerk (City Clerk)