Unified Stormwater Rule - NYC DEP

Environmental Protection


Stormwater Management

Unified Stormwater Rule


The Unified Stormwater Rule updated and aligned water quantity requirements in the city’s combined sewer drainage areas with water quality requirements in separately sewered drainage areas, providing a comprehensive, citywide stormwater management policy for public and private development. The NYC Stormwater Manual provides a comprehensive overview of NYC stormwater management requirements and design guidance for developers, designers, and engineers who work on projects that must comply with the requirements of Site/House Connection Proposal Certifications and Stormwater Permits.

Download a list of Unified Stormwater Rule Frequently Asked Questions and Responses compiled during the public comment period.

New York City Stormwater Manual

The NYC Stormwater Manual provides technical guidance that emphasizes a retention-first, green infrastructure approach to stormwater management practice selection and design.

Download the New York City Stormwater Manual

Download Appendix A: Stormwater Management Practice Hierarchy Checklist

Download Appendix B: Nitrogen No Net Increase Calculator Guide Placeholder

Download Appendix C: Stormwater Management Practice Siting Criteria

Download Appendix D: Stormwater Management Practice Sizing Example

Download Appendix E: Site Design Example

Download Appendix F: Controlled Flow Pump Workbook

Download Appendix G: Detention Series Workbook

Download Appendix G: Detention Series Examples

Download Appendix H: Right of Way Guidance Materials

Download Appendix H: Right of Way Stormwater Management Practices Data Tracking Form Workbook