The Philadelphia Stormwater Management Guidance Manual Version 3.2 is now live. It provides comprehensive stormwater management guidance for all private property, including both regulated Development and voluntary Stormwater Retrofit projects.

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What to Expect from the Update: 

  • Greater continuity between design and construction requirements for regulated and voluntary retrofit projects.
  • Detailed instructions on the review process for regulated Development projects, voluntary Stormwater Retrofit projects, and hybrid projects.
  • Updates to account for an almost completely virtual review and permitting process at PWD and between PWD and L+I.  This includes guidance for online plan submission through www.pwdplanreview.org
  • Detailed information and critical considerations for Stormwater Retrofit projects as well as updates on the Stormwater Credits program. 

What Else We Updated:  

  • An increase in the maximum loading ratio for all subsurface infiltration systems (regulated and voluntary retrofit projects) to 10:1. 
  • Reorganization of Sections 3.1 and 3.2 for ease in locating specific design requirements such as Disconnected Impervious Cover, Stormwater Management Practice (SMP) Hierarchy, and Stormwater Management Banking and Trading.  
  • A modification of the SMP Hierarchy to remove porous asphalt and porous concrete as highest-preference SMPs. Any new ERSA Applications received on or after October 1st, 2020 cannot use these materials to qualify for Expedited PCSMP Reviews.      
  • An expanded suite of Standard Details, now included under a new Appendix to the Manual, Appendix L. 
  • Formalized standards for the required creation of an SMP Maintenance Guide, with associated documents now included under a new Appendix to the Manual, Appendix G. 
  • Expanded basin setback requirements and exceptions for bioinfiltration/bioretention, subsurface infiltration, and subsurface detention. 
  • Modified requirements for soil sampling, cased borehole soil characterization borings, and cased borehole infiltration testing. 
  • Other updates to clarify existing policies and better reflect current design requirements and review procedures.  

In general, the format and overall chapter organization will be the same as the Manual v3.1. There have been no changes to the baseline regulatory requirements or earth disturbance thresholds for regulated Development projects.  Applicants should begin using the new Manual immediately when it is launched. This includes applications for regulated development projects currently undergoing review, as well as voluntary Stormwater Retrofit projects that applied for the FY21 Stormwater Grant Funding cycle. There will be no grandfathering under the existing Manual, with the exception of Expedited PCSMP Review eligibility as discussed above.