Stormwater Code
Director's Rules
- DR 13-2010, SPU 5-2010, Groundwater / Dewatering - NEW!
- DR 15-2009, SPU 2009-003, Vol. I - Source Control Technical Requirements Manual, presents approved methods, criteria, details, and general guidance for controlling pollutants at their source.
- DR 16-2009, SPU 2009-004, Vol. II - Construction Stormwater Control Technical Requirements Manual, presents approved methods, criteria, details, and general guidance for preventing contaminants from leaving a site during construction. Best management practices focus on erosion control and water quality treatment for runoff.
- DR 17-2009, SPU 2009-005, Vol. III - Stormwater Flow Control and Water Quality Treatment Technical Requirements Manual, presents approved methods, requirements, criteria, details, and general guidance for analysis and design of flow control and water quality facilities.
- Appendix A - Definitions
- Appendix B - Design Storm Dimensionless Hyetograph Ordinates
- Appendix C - Precipitation Magnitude-Frequency Estimates for SPU Rain Gauge Locations (up to 2003 data only)
- Appendix D - Facility Operations and Maintenance Requirements
- Appendix E - City of Seattle Modified Procedure for Conducting a Pilot Infiltration Test
- Appendix F - Geotextile Specifications
- DR 18-2009, SPU 2009-006, Vol. IV - Stormwater Code Enforcement Manual, interprets enforcement standards and procedures for stormwater requirements. It is intended to clarify the application of enforcement for businesses, developers, the general public, and public agencies in Seattle. Establishes a matrix with a sliding scale of penalties, based on severity of the code violation.
- Green Stormwater Infrastructure - Requirements for Projects (under development)
Last Updated: Sept. 22, 2010

