2022 County-wide Act 167 Stormwater Management Model Ordinance
On August 17, 2022, the Chester County Board of Commissioners adopted Resolution 55-22 to amend the County-wide Act 167 Stormwater Management Plan for Chester County, PA to replace the 2013 model ordinance with the 2022 County-wide Act 167 Stormwater Management Model Ordinance.
Following the Commissioners’ adoption, Chester County submitted the adopted Model Ordinance and appendices to the Pennsylvania Department of Environmental Protection (PA DEP) for their final review in accordance with the Pennsylvania Stormwater Management Act (PA Act 167). This updated ordinance incorporates PA DEP's comments from their review of the Model Ordinance to improve consistency with their state-wide 2022 Stormwater Management Model Ordinance. Three primary changes were incorporated into the County-wide Model Ordinance to address PA DEP’s comments. PA DEP has reviewed these changes and noted that they have no further comments on the County-wide Model Ordinance. The re-adopted ordinance is under final review by PA DEP, who will issue a final approval letter of the updated ordinance. Subsections modified to address PA DEP's comments are listed below with a description of the changes made.
- Subsection 305.A: The following text was removed from the adopted Model Ordinance: “or a minimum of one and one half (1.5)-inches of runoff from all Regulated Impervious Surfaces shall be managed. Whichever volume is greater shall be managed.” Thus, this section will remain unchanged from the 2013 Model Ordinance.
- Section 309.B: The reference to NOAA Atlas 14 was updated to state the following: “the latest version of the Precipitation-Frequency Atlas of the United States, National Oceanic and Atmospheric Administration (NOAA), National Weather Service, Hydrometeorological Design Studies Center, Silver Spring, Maryland (NOAA Atlas 14)”.
- Section 706: The inspection requirements for both the municipal inspection (Option 1) and landowners inspection (Option 2) options were modified. Option 1 was modified to state that MS4 municipalities are required to inspect BMPs after each 25-year storm event. Language was also added to provide municipalities with the choice to request the owner of a BMP to complete an inspection after a 10-year event. Option 2 was modified to require inspections after each 10-year event, but inspection reports are only required to be submitted if requested by the municipality.
Model Ordinance Implementation Workshops
The Chester County Water Resources Authority hosted two implementation workshops to assist municipalities with updating their stormwater ordinance. Links to the recordings and PDFs of presentations delivered at both workshops can be found at this page
Please email us at [email protected] with questions relating to the material presented at these workshops or if you have other questions about the updated Model Ordinance.
Links to updated versions of the adopted Model Ordinance and supporting documents can be found below. The following documents were also updated for consistency with the changes to the Model Ordinance: Appendix B, Appendix E, the Matrix of Minimum Standards, Summary of Changes, and Summary of Options. Municipalities should reference these latest documents when updating their ordinance to be consistent with PA DEP’s 2022 Model Ordinance and the County-wide Act 167 Model Stormwater Ordinance.
County-wide Act 167 Stormwater Management Ordinance
- County-wide Act 167 Stormwater Management Model Ordinance (Word document)
Clean Version with PA DEP Changes Included as Track Changes (Updated 6/2/2022 with PA DEP Revisions)
- County-wide Act 167 Stormwater Management Model Ordinance with all changes highlighted (Updated 6/2/2022 with PA DEP revisions)
- Model Ordinance Appendix A: Simplified Approach to Stormwater Management for Small Projects (Word document)
- Model Ordinance Appendix B: Conservation Design and Low Impact Development Site Design (Word document, Updated 6/2/2022)
- Model Ordinance Appendix C (Complete PDF):
- Model Ordinance Appendix D: West Nile Virus Design Guidance (Word document)
- Model Ordinance Appendix E: Stormwater Best Management Practices and Conveyances Operation and Maintenance Sample Agreement (Updated 6/2/2022)
Note: It is recommended that municipalities adopt the Model Ordinance as a stand-alone ordinance. Municipalities do not need to submit their updated ordinance to the Chester County Planning Commission or the Chester County Water Resources Authority (CCWRA) prior to adoption. After the ordinance has been adopted, we ask that an electronic copy along with the completed “Certification of Ordinance Adoption” (linked below) be submitted to CCWRA at [email protected].
The Chester County Water Resources Authority encourages all municipalities to begin reviewing the adopted Model Ordinance and assessing which optional provisions will be included in your updated ordinance. Municipalities with MS4 permits should plan to update their ordinances to be consistent with the updated County-wide Model Ordinance by September 30, 2022, or by the submission of the fourth Annual MS4 Status Report following permit coverage (for new permittees).. Below are additional resources to assist Municipalities with updating their ordinances to be consistent with the County-wide Model Ordinance.
- Summary of Changes Table (Updated 6/2/2022): The Summary of Changes Table lists all of the substantive changes made to the 2013 model ordinance.
- Matrix of Minimum Mandatory Ordinance Standards (Updated 6/2/2022): The Matrix of Minimal Mandatory Standards outlines the minimum standards municipal ordinances must include to be consistent with the County-wide Model Ordinance. The Municipality may set more restrictive or stringent standards and requirements than those included in the Matrix, but they cannot set less restrictive standards.
- List of Model Ordinance Sections with Options for Modifying Standards and Requirements (Updated 6/2/2022): This resource provides a comprehensive overview of all sections in the Model Ordinance where the Municipality is presented with choices for determining the level and extent of the standards and requirements to be included in their Ordinance.
- Certification of Ordinance Adoption Form (Word document): Upon final adoption of the model ordinance or equivalent minimum mandatory ordinance standards, each municipality must submit this form to Pennsylvania Department of Environmental Protection’s Bureau of Point and Non-Point Source Management and send a copy to the Chester County Water Resources Authority.
- Example Schedule of Fees (Word document): This example schedule of fees has been modified from the Crum Creek Act 167 Model Ordinance. This document is meant only as an example, and can be modified by the municipality to meet their needs. If the municipality chooses to require fees for stormwater site plan reviews and BMP inspections, it is recommended that a fee schedule be adopted independent of the ordinance to allow for fees to be adjusted as needed without having to go through the public hearing process.
- Response to 45 Day Public Review Comments: This document includes responses to the comments received during the 45-day public review and comment period.
- Watershed Plan Advisory Committee (WPAC) Meetings, Communications, and Members and Public and Stakeholder Meetings and Presentations: This document lists all of the Watershed Plan Advisory Committee (WPAC) meetings, all email communications to the municipalities, and all public and stakeholder input meetings.
The updated Model Ordinance is the culmination of nearly three years of collaboration between Chester County, its municipalities, residents, and other stakeholders. Over this period, the Chester County Water Resources Authority hosted or presented at 36 in-person and virtual public and stakeholder input meetings designed to identify ways to improve the implementation and effectiveness of the County’s 2013 model ordinance. The County solicited additional input through the creation of a stormwater management survey that was distributed to municipalities and residents. The updated Model Ordinance was significantly shaped by the input received through these efforts.
The updated Model Ordinance was designed to meet the needs of Chester County municipalities, fulfill the standards set forth in the Pennsylvania Storm Water Management Act (“Act 167”), and comply with the regulatory requirements of Pennsylvania Department of Environmental Protections’ (PA DEP) National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) program. The updates incorporated into the Model Ordinance were also designed to comply with the provisions included in PA DEP's 2022 Model Stormwater Management Ordinance.
Section 706 of the updated Model ordinance requires inspections of BMPs installed after the adoption of this ordinance to be inspected during or immediately after the cessation of a 25-year or greater storm (for inspections conducted by the municipality) or 10-year or greater storm (all other inspections). Municipalities and those with BMP inspection responsibilities should reference NOAA Atlas 14 when assessing when inspections are required. The chart below provides information on average return intervals for Chester County.
NOAA Atlas 14 Precipitation Estimates
Average of seven locations throughout Chester County, PA
Links to subscribe to real-time precipitation data from the seven USGS precipitation gages in the County are below:
- Schuylkill River at Pottstown (North Coventry Township | Pottstown Borough)
- Valley Creek at PA Turnpike Bridge near Valley Forge (Tredyffrin Township)
- Chambers Lake near Wagontown (West Caln Township)
- West Branch Brandywine Creek at Modena (Modena Borough)
- East Branch Brandywine Creek below Downingtown (East Bradford Twp | West Bradford Twp)
- Brandywine Creek at Chadds Ford (Pennsbury Township | Chadds Ford Township)
- East Branch Big Elk Creek at Forestville (Penn Township | Upper Oxford Township)
Additional precipitation data for Chester County can be found at the following links:
- County-wide Act 167 Stormwater Management Plan
- 2013 County-wide Stormwater Management Model Ordinance
- Improving Stormwater Management in Chester County
- PA DEP's 2022 Model Stormwater Management Ordinance
- Pennsylvania Stormwater Best Management Practices Manual
- Chester County's Erosion and Sedimentation Control Program