- Introduction
- Ch. 1 Stormwater Management Requirements
- Ch. 2 Submission, Review, and Approval Procedures
- Ch. 3 Site Design and Stormwater Management Integration
- Ch. 4 Stormwater Management Practice Guidance
- Ch. 5 Construction Guidance
- Ch. 6 Post-Construction and Operations and Maintenance Guidance
- Appendices
- Download
- Back to Chapters
- Manual Organization and Purpose
- Stormwater Regulations
- Private Development Services
- Stormwater Billing and Incentives
- Stormwater Management in Philadelphia
- Applicability and Submission Process
- Preferred Design Approach
- Back to Chapters
- 1.0 Introduction
- 1.1 Applicability Factors
- 1.2 Stormwater Regulations
- 1.3 Stormwater Retrofits
- Back to Chapter 1
- 1.2.1 Post-Construction Stormwater Management Requirements
- 1.2.2 Erosion and Sediment Control Requirement
- Back to Chapter 1
- 1.3.1 Retrofit Project Applicability and Initiation
- 1.3.2 Retrofit Project Requirements and Guidance
- Back to Chapters
- 2.0 Introduction
- 2.1 Existing Resources and Site Analysis
- 2.2 Review Paths
- 2.3 Review Phases
- 2.4 Expedited Post-Construction Stormwater Management Plan Reviews
- 2.5 PWD’s Development Review Process
- 2.6 PWD’s Role in Philadelphia's Development Process
- 2.7 PWD and Pennsylvania Department of Environmental Protection
- Back to Chapter 2
- 2.2.1 Development Compliance Review Path
- 2.2.2 Development Exemption Review Path
- 2.2.3 Demolition Review Path
- 2.2.4 Stormwater Retrofit Review Path
- Back to Chapter 2
- 2.3.1 Development Compliance Review Path
- 2.3.2 Development Exemption Review Path
- 2.3.3 Demolition Review Path
- 2.3.4 Stormwater Retrofit Review Path
- Back to Chapter 2
- 2.4.1 Disconnection Green Review
- 2.4.2 Surface Green Review
- 2.4.3 Expedited PCSMP Review Process
- Back to Chapter 2
- 2.7.1 National Pollutant Discharge Elimination System Permits
- 2.7.2 Other PA DEP Requirements
- Back to Chapters
- 3.0 Introduction
- 3.1 Site Assessment and Stormwater Management Strategies
- 3.2 Stormwater Management Design
- 3.3 Infiltration Testing and Soil Assessment for SMP Design
- 3.4 How To Show Compliance
- 3.5 Integrated Stormwater Management Examples
- Back to Chapter 3
- 3.0.1 How to Use This Chapter
- 3.0.2 Integrated Site and Stormwater Management Assessment and Design Process Overview
- 3.0.3 Interactions between Design Strategies, Stormwater Regulations, and Review Paths
- Back to Chapter 3
- 3.1.1 Background Site Factors and Site Factors Inventory
- 3.1.2 Site Factors Analysis
- 3.1.3 Integrated Design Approach
- 3.1.4 Non-Structural Design
- 3.1.5 Disconnected Impervious Cover
- 3.1.6 SMP Functions
- 3.1.7 Pollutant- Reducing Practices and Roof Runoff Isolation
- 3.1.8 How to Use SMPs to Comply with the Regulations
- Back to Chapter 3
- 3.2.1 Major SMP Types
- 3.2.2 SMP Hierarchy and Selection Process
- 3.2.3 Placing SMPs in Series
- 3.2.4 Stormwater Management Banking and Trading
- 3.2.5 SMP Design Guidance and General Requirements
- 3.2.6 Loading Ratio Requirements
- 3.2.7 Planting and Vegetation Guidance
- 3.2.8 Operations and Maintenance
- Back to Chapter 3
- 3.3.1 Infiltration Testing and Soil Characterization Plan Development
- 3.3.2 Soil Characterization Requirements
- 3.3.3 Infiltration Testing Requirements
- 3.3.4 Soil Characterization Procedures
- 3.3.5 Infiltration Testing Procedures
- 3.3.6 Evaluation of Infiltration Testing Results
- Back to Chapter 3
- 3.4.1 Regulatory Compliance Documentation Requirements
- 3.4.2 Storm Sewer Design Requirements
- 3.4.3 Calculation Methods and Design Tools
- Back to Chapter 3
- 3.5.1 Commercial Office Building Development
- 3.5.2 Residential Multi-Family Development
- 3.5.3 Full Build-Out
- 3.5.4 Trails
- 3.5.5 Athletic Fields
- 3.5.6 Streets
- Back to Chapters
- 4.0 Introduction
- 4.1 Bioinfiltration/ Bioretention
- 4.2 Porous Pavement
- 4.3 Green Roofs
- 4.4 Subsurface Infiltration
- 4.5 Cisterns
- 4.6 Blue Roofs
- 4.7 Ponds and Wet Basins
- 4.8 Subsurface Detention
- 4.9 Media Filters
- 4.10 Pretreatment
- 4.11 Inlet Controls
- 4.12 Outlet Controls
- Back to Chapter 4
- 4.1.1 Bioinfiltration/ Bioretention Introduction
- 4.1.2 Bioinfiltration/ Bioretention Components
- 4.1.3 Bioinfiltration/ Bioretention Design Standards
- 4.1.4 Bioinfiltration/ Bioretention Material Standards
- 4.1.5 Bioinfiltration/ Bioretention Construction Guidance
- 4.1.6 Bioinfiltration/ Bioretention Maintenance Guidance
- Back to Chapter 4
- 4.2.1 Porous Pavement Introduction
- 4.2.2 Porous Pavement Components
- 4.2.3 Porous Pavement Design Standards
- 4.2.4 Porous Pavement Material Standards
- 4.2.5 Porous Pavement Construction Guidance
- 4.2.6 Porous Pavement Maintenance Guidance
- Back to Chapter 4
- 4.3.1 Green Roof Introduction
- 4.3.2 Green Roof Components
- 4.3.3 Green Roof Design Standards
- 4.3.4 Green Roof Material Standards
- 4.3.5 Green Roof Construction Guidance
- 4.3.6 Green Roof Maintenance Guidance
- Back to Chapter 4
- 4.4.1 Subsurface Infiltration Introduction
- 4.4.2 Subsurface Infiltration Components
- 4.4.3 Subsurface Infiltration Design Standards
- 4.4.4 Subsurface Infiltration Material Standards
- 4.4.5 Subsurface Infiltration Construction Guidance
- 4.4.6 Subsurface Infiltration Maintenance Guidance
- Back to Chapter 4
- 4.5.1 Cistern Introduction
- 4.5.2 Cistern Components
- 4.5.3 Cistern Design Standards
- 4.5.4 Cistern Material Standards
- 4.5.5 Cistern Construction Guidance
- 4.5.6 Cistern Maintenance Guidance
- Back to Chapter 4
- 4.6.1 Blue Roof Introduction
- 4.6.2 Blue Roof Components
- 4.6.3 Blue Roof Design Standards
- 4.6.4 Blue Roof Material Standards
- 4.6.5 Blue Roof Construction Guidance
- 4.6.6 Blue Roof Maintenance Guidance
- Back to Chapter 4
- 4.7.1 Pond and Wet Basin Introduction
- 4.7.2 Pond and Wet Basin Components
- 4.7.3 Pond and Wet Basin Design Standards
- 4.7.4 Pond and Wet Basin Material Standards
- 4.7.5 Pond and Wet Basin Construction Guidance
- 4.7.6 Pond and Wet Basin Maintenance Guidance
- Back to Chapter 4
- 4.8.1 Subsurface Detention Introduction
- 4.8.2 Subsurface Detention Components
- 4.8.3 Subsurface Detention Design Standards
- 4.8.4 Subsurface Detention Material Standards
- 4.8.5 Subsurface Detention Construction Guidance
- 4.8.6 Subsurface Detention Maintenance Guidance
- Back to Chapter 4
- 4.9.1 Media Filter Introduction
- 4.9.2 Media Filter Components
- 4.9.3 Media Filter Design Standards
- 4.9.4 Media Filter Material Standards
- 4.9.5 Media Filter Construction Guidance
- 4.9.6 Media Filter Maintenance Guidance
- Back to Chapter 4
- 4.10.1 Pretreatment Introduction
- 4.10.2 Filter Strips
- 4.10.3 Forebays
- 4.10.4 Swales
- Back to Chapter 4
- 4.11.1 Inlet Control Introduction
- 4.11.2 Flow Splitters
- 4.11.3 Curbless Design/Curb Openings
- 4.11.4 Energy Dissipaters
- 4.11.5 Inlets
- Back to Chapter 4
- 4.12.1 Outlet Control Introduction
- 4.12.2 Orifices
- 4.12.3 Weirs
- 4.12.4 Risers
- 4.12.5 Underdrains
- 4.12.6 Level Spreaders
- 4.12.7 Impervious Liners
- 4.12.8 Micro Siphon Drain Belts
- 4.12.9 Low Flow Devices
- Back to Chapters
- 5.0 Introduction
- 5.1 Construction Inspection
- 5.2 Common Construction Issues
- 5.3 Construction Documentation
- Back to Chapter 5
- 5.1.1 Coordinating Inspections with Other PWD Units
- 5.1.2 Preconstruction Processes
- 5.1.3 Construction Processes
- 5.1.4 Final Inspection
- 5.1.5 Post-Construction Submissions
- Back to Chapter 5
- 5.2.1 Erosion and Sediment-Related Construction Issues
- 5.2.2 Stormwater Management Practice-Related Construction Issues
- Back to Chapters
- 6.0 Introduction
- 6.1 Operations and Maintenance
- 6.2 Stormwater Management Practice Inspection Guidance
- 6.3 Stormwater Credits Program
- Back to Chapter 6
- 6.1.1 Maintenance Requirements for Property Owners
- 6.1.2 Operations and Maintenance Agreements
- Back to Chapters
- Appendix Index
- A. Glossary
- B. Abbreviations
- C. PWD Stormwater Regulations
- D. Watershed Maps
- E. Plan and Report Checklists
- F. Design Guidance Checklists
- G. SMP Maintenance Guide Documents
- H. Infiltration Testing Log
- I. Landscape Guidance
- J. Construction Certification Package
- K. Record Drawing Sample
- L. Standard Details
- Back to Appendices
- Table E-1: General Plan Sheet Requirements
- Table E-2: Existing Conditions Plan Requirements
- Table E-3: Conceptual Stormwater Management Plan Requirements
- Table E-4: Erosion and Sediment Control Plan Requirements
- Table E-5: Standard Erosion and Sediment Control Notes
- Table E-6: Standard Sequence of Construction Notes
- Table E-7: Post-Construction Stormwater Management Plan Report Requirements
- Table E-8: Record Drawing Requirements
- Back to Appendices
- F.1 Stormwater Regulation Compliance
- F.2 Post-Construction Stormwater Management Plan
- F.3 Erosion and Sediment Control
- F.4 Disconnected Impervious Cover
- F.5 Infiltration Testing and Soil Assessment
- F.6 Hydrologic Model and Calculation Methods
- F.7 Bioinfiltration/ Bioretention
- F.8 Porous Pavement
- F.9 Green Roofs
- F.10 Subsurface Infiltration
- F.11 Cisterns
- F.12 Blue Roofs
- F.13 Ponds and Wet Basins
- F.14 Subsurface Detention
- F.15 Media Filters
- F.16 Pretreatment
- F.17 Inlet Controls
- F.18 Outlet Controls
Appendix Index
Appendix | Description |
A. Glossary | List of key words or terms included in the text of the Manual. |
B. Abbreviations | Compiled list and explanations of all abbreviations used in the Manual.
|
C. PWD Stormwater Regulations | The Stormwater Regulations, presented in Appendix C, have been developed in accordance with the Philadelphia Code §14-704(3), and they consist of four major Post-Construction Stormwater Management (PCSM) Requirements: Water Quality, Channel Protection, Flood Control, and Public Health and Safety (PHS) Release Rate. In addition, all earth disturbance activity must comply with the Erosion and Sediment Control (E&S) requirements of the Pennsylvania Department of Environmental Protection, as specified in 25 Pa. Code §102.4.
The objectives of these requirements include:
|
D. Watershed Maps | Watershed location plays an important role in identifying how the Stormwater Regulations, specifically the Post-Construction Stormwater Management Requirements, are applied to a project. Once the location of the development site is determined, Appendix D may be used to evaluate its Flood Management District and sewershed. If they are unable to confirm either, the applicant should contact Stormwater Plan Review. |
E. Plan and Report Checklists | Section 2.3 provides Review Phase Submission Package checklists as well as detailed guidance on the submission process. Appendix E includes checklists itemizing the submittal requirements of plans and reports required for Review Phase Submission Packages. By ensuring that plans and reports meet the requirements identified in each checklist, the applicant can streamline their project's Review Phase. |
F. Design Guidance Checklists | The Philadelphia Water Department's Stormwater Plan Review Design Guidance Checklists, contained in Appendix F, are a supplemental list of guidelines for Regulatory compliance, plan creation, hydrologic modeling and calculations, and the design of specific stormwater management practices. They are provided to assist in the formation of both sound, compliant stormwater management designs and complete Post-Construction Stormwater Management Plan (PCSMP) submissions. The designer should use the checklists as guidance during the design and calculation stages or as useful quality assurance/quality control checks prior to PCSMP Review Phase submission. |
G. SMP Maintenance Guide Documents | Appendix G contains the SMP Maintenance Guide and its associated documents. An SMP-specific, site-specific SMP Maintenance Guide, prepared by the designer and submitted to, and reviewed by, PWD during the PCSMP Review Phase, should be provided to and implemented by the property owner as a guide for long-term operations and maintenance of the SMPs on-site. SMP Maintenance Guide instructions are available on the first page of the SMP Maintenance Guide to guide the designer through the creation of these items. The SMP Maintenance Guide must be accompanied by a Site Map and a separate Maintenance Schedule Form for each SMP to allow the property owner to track all maintenance activities for their site. SMP Maintenance Guidance One-Sheets are available for each SMP detailed in this Manual in order to provide guidance on SMP maintenance activities and frequencies, including recommended SMP maintenance schedules. |
H. Infiltration Testing Log | Appendix H contains a template log for documenting infiltration testing results. This Infiltration Testing Log includes guidance for documenting soil characteristics and is required to be completed and submitted as part of the Geotechnical Report during the Post-Construction Stormwater Management Plan Review Phase. |
I. Landscape Guidance | Detailed guidance and specifications for landscaping, including native and recommended non-invasive and prohibited non-native and invasive plant lists. |
J. Construction Certification Package | It is important, both for the property owner and for the Philadelphia Water Department (PWD), to ensure that all stormwater management practices (SMPs) are constructed in strict accordance with the Approved Post-Construction Stormwater Management Plan (PCSMP). The Construction Certification Package (CCP) provides PWD with documentation that SMPs have been properly installated. Consisting of photographs, material receipts, and SMP Construction Certification Forms which must be customized by the design engineer prior to PCSMP Approval, the CCP must be kept on-site and completed by a registered professional during construction. Appendix J contains a description of the required CCP documentation and a collection of customizable SMP Construction Certification Forms to be populated with key information during construction and installation. |
K. Record Drawing Sample | Along with the Construction Certification Package, the Philadelphia Water Department (PWD) requires that Record Drawing(s) be submitted at the close of the project to ensure that the stormwater management practices (SMPs) and their elements were constructed in general accordance with the Approved Post-Construction Stormwater Management Plan (PCSMP), and to document any field changes. Record Drawing(s) are required for SMP verification and are a key component of PWD’s compliance reporting. Samples which demonstrate how Approved PCSMP plan sheets should be marked-up in order to prepare Record Drawings are provided in Appendix K. |
L. Standard Details | Typical construction details for several SMPs, including all of PWD’s highest-preference SMPs, such as bioinfiltration/bioretention basins, porous pavement, and green roof, and for SMP-related structures, such as cleanouts, observations wells, and outlet control structures, are available for download in AutoCAD (*.dwg) format in Appendix L. These Standard Details incorporate design specifications pursuant to each SMP’s respective design and material requirements. The designer is encouraged, not required, to use them for PCSMP creation when possible. |
A. Glossary
Applicant: A property owner, developer, or other person or entity who has filed an application to the Philadelphia Water Department (PWD) for approval to engage in or be exempt from any Regulated Activity at a Development Site in the City of Philadelphia.
Combined Sewer Overflows (CSO): A combined sewer overflow is an intermittent overflow or other untreated discharge from a municipal combined sewer system to the water of the Commonwealth occurring before the sewage treatment plant.
Conceptual Stormwater Management Plan: A preliminary stormwater management plan used by PWD Stormwater Plan Review to understand what is proposed at the project site, to confirm the proposed project limits of disturbance (LOD), and to assess the proposed stormwater management strategy. Conceptual Stormwater Management Plan requirements are described in Chapter 2 of this Manual.
Demolition: The razing or destruction, whether entirely or in significant part, of a building, structure, site, or object; including the removal of a building, structure, site, or object from its site or the removal or destruction of the façade or surface.
Design Storm: The magnitude and temporal distribution of precipitation from a storm event defined by probability of occurrence (e.g., five-year storm) and duration (e.g., 24 hours), used in the design and evaluation of stormwater management systems.
Developer: Any landowner, agent of such landowner, or tenant with the permission of such landowner, who makes or causes to be made a subdivision of land or land Development project prior to issuance of the Certificate of Occupancy.
Development: Any human-induced change to a tract of land, whether public or private. Development encompasses, but is not limited to, New Development, Redevelopment, Demolition, and Stormwater Retrofit. It includes the entire Development Site, even when the project is performed in phases.
Development Site: The land area where any Development activities are planned, conducted, or maintained, regardless of individual parcel ownership. It includes contiguous areas of disturbance across Streets and other rights of way, or private streets and alleys, during any stage of or on any portion of a larger common plan of development or sale.
Diffused Drainage Discharge: Drainage discharge not confined to a single point location or channel, such as sheet flow or shallow concentrated flow.
Directly Connected Impervious Area (DCIA): An Impervious Surface that is directly connected to the drainage system. DCIA generates surface runoff with a direct hydraulic connection to on-site drainage systems (e.g., inlets, curbs and gutters, pipes, etc.), PWD’s drainage systems, or stormwater management practices (SMPs) without flowing over pervious areas.
Disconnected Impervious Cover (DIC): Impervious cover from which runoff is directed toward pervious areas for management within the landscape.
Earth Disturbance: Any construction or other activity that disturbs the surface of land, including but not limited to, excavations, embankments, land development, subdivision development, and the moving, depositing, or storing of soil, rock, or earth. Other examples of earth disturbance in the context of PWD Stormwater Regulations are listed in Section 1.1.3.
Erosion and Sediment (E&S) Control Plan: A site-specific plan consisting of both drawings and a narrative that identifies measures to minimize accelerated erosion and sedimentation before, during, and after Earth Disturbance. E&S Plan requirements are described in Chapter 2 of this Manual.
Evaporation and Transpiration (Evapotranspiration): Evaporation is the process by which water changes from a liquid to gas. Transpiration is the process by which water moves through a plant and evaporates into the atmosphere from its leaves and exterior surfaces. The sum of evaporation and transpiration are commonly referred to as evapotranspiration.
Existing Conditions: Physical conditions on the site including land use, impervious surface, topography, vegetation, soils, and hydrology that exist on the site on the date the owner starts the development process.
Groundwater Recharge: The replenishment of existing natural underground water supplies from precipitation or overland flow without degrading groundwater quality.
Hotspots: Areas where land use or activities have contaminated the soil underlying the site such that infiltration of stormwater would likely cause groundwater contamination through leaching of the soil.
Impervious Liner: A physical barrier to prevent water from crossing a system boundary such as infiltrating through the subgrade beneath a stormwater management practice. Liners may include, but are not limited to, compacted till liners, clay liners, geomembrane liners, and concrete liners.
Impervious Surface: Any building, pavement, or other material that substantially bars the natural infiltration of surface water into the soil.
Infiltration: The process by which water enters the soil from the ground surface and can be measured as a rate.
Management District: Sub-area delineations that determine peak rate attenuation requirements. A Development Site located in more than one Management District shall conform to the requirements of the district into which the site discharges
Manual: The most recent version of the Philadelphia Stormwater Management Guidance Manual.
New Development: Development project on a tract of land where structures or impervious surfaces never existed or were removed before January 1, 1970.
Non-Structural Design: Stormwater management practices that incorporate, preserve, and protect existing natural features while promoting treatment, infiltration, evaporation, and transpiration of precipitation close to where it falls.
Operations & Maintenance (O&M) Agreement: An agreement or declaration which outlines the maintenance requirements associated with the Post-Construction Stormwater Management Plan.
Pavement Disconnection: A type of DIC and a reduction in DCIA when pavement runoff is directed to a vegetated area that allows for infiltration, filtration, and an increased time of concentration.
Post-Construction Stormwater Management Plan (PCSMP): A complete stormwater management plan set as described in the PWD Stormwater Regulations and in this Manual. PCSMP requirements are described in Chapter 2 of this Manual.
Predevelopment Condition: For New Development and Redevelopment, the dominant land use for the previous ten years preceding the planned project.
Record Drawings: Construction drawings revised to represent the as-built conditions.
Redevelopment: Development on a tract of land that includes, but is not limited to, the demolition or removal of existing structures or impervious surfaces and replacement with new impervious surfaces. This includes replacement of impervious surfaces that have been removed on or after January 1, 1970.
Registered Professional: A licensed Professional Engineer, Registered Architect, Landscape Architect, Professional Land Surveyor, Professional Geologist, or Licensed Contractor registered in the Commonwealth of Pennsylvania.
Regulated Activity: Development on a Development Site in the City of Philadelphia that results in an area of Earth Disturbance greater than or equal to 15,000 square feet, greater than or equal to 5,000 square feet in the Darby and Cobbs Creeks Watershed, or as otherwise required by local, State, or Federal requirements. The area of Earth Disturbance during the construction phase determines requirements for the erosion and sediment controls and post-construction stormwater management.
Review Path: A linear series of submission, review, and approval/exemption procedures the applicant will navigate to demonstrate a project’s compliance with, or exemption from, the PWD Stormwater Regulations.
Review Phase: A step in a Review Path. Each Review Path has one or more Phases. Each Phase corresponds to one or more submittals of information for PWD's review.
Roof Runoff Isolation: The routing of runoff from non-vehicular roof area that is not commingled with untreated runoff.
Rooftop Disconnection: A type of DIC and a reduction in DCIA when a roof downspout is directed to a vegetated area which allows for infiltration, filtration, and increased time of concentration.
Sewershed: An area of land, or catchment, which drains via storm drain infrastructure to a common outlet point.
Site Assessment: An investigation of the administrative and physical factors that shape the development and stormwater management plan for a proposed site. The assessment consists of three components – collection of background site factors, site factors inventory, and site factors analysis.
Storage Volume: The volume of stormwater runoff that can be held within the above-ground surface area and the pore spaces of any subsurface media or structure of a stormwater management practice.
Stormwater Management Practice (SMP): Any man-made or natural structure, system, landscape feature, channel, or improvement designed, constructed, installed, and/or used to detain, infiltrate, or otherwise control stormwater runoff quality, rate, or quantity.
Stormwater Pretreatment: Techniques employed to remove pollutants before they enter the SMP, including, but not limited to, the techniques listed as pretreatment in this Manual.
Stormwater Retrofit: The voluntary rehabilitation and/or installation of SMPs on a property to better manage stormwater runoff.
Street: Tract of land or part thereof with public access used for vehicular and/or pedestrian traffic, which is maintained by a City Agency, City Related Agency, other Government Agency, or a Non-Profit Organization Created by the City, as determined by the Department.
Street Maintenance Activities: Earth Disturbance activities within an existing Street as determined by the Department and described in the Manual Section 1.1.3.
Tree Disconnection Credit: A type of DIC and a reduction in DCIA when existing or newly proposed tree canopy from an approved species list extends over, or is in close proximity to, impervious area.
Watershed: An area of land that contains a common set of drainage pathways, streams, and rivers that all discharge to a single large body of water, such as a large river, lake, or ocean.
B. Abbreviations
AASHTO |
American Association of State Highway and Transportation Officials |
ANSI |
American National Standards Institute |
ASSE |
American Society of Safety Engineering |
ASTM |
American Society of Testing and Materials |
BMP |
Best Management Practice |
CCP |
Construction Certification Package |
CCTV |
Closed Circuit Television |
CIP |
Cast Iron Pipe |
cfs |
Cubic Feet per Second |
CERCLA |
Comprehensive Environmental Response, Compensation, and Liability Act |
CERM |
Civil Engineering Reference Manual |
CN |
Curve Number |
CO&A |
Consent Order and Agreement |
CSO |
Combined Sewer Overflow |
CWA |
Clean Water Act (1972) |
DCIA |
Directly Connected Impervious Area |
DIC |
Disconnected Impervious Cover |
DOR |
Department of Records |
EMC |
Event Mean Concentration |
EMI |
Electromagnetic Induction |
E&S |
Erosion and Sediment Control |
EPDM |
Ethylene Propylene Diene Terpolymer |
ERSA |
Existing Resources and Site Analysis |
ET |
Evapotranspiration |
FLL |
German Landscape Research, Development and Construction Society |
FEMA |
Federal Emergency Management Agency |
GARP |
Greened Acre Retrofit Program |
GPR |
Ground Penetrating Radar |
GSI |
Green Stormwater Infrastructure |
HDPE |
High-Density Polyethylene |
HOA |
Homeowners Association |
HSG |
Hydrologic Soil Group |
IDF |
Intensity-Duration-Frequency |
IWU |
Industrial Waste Unit |
LEED |
Leadership in Energy and Environmental Design |
L&I |
Department of Licenses and Inspections |
LOD |
Limit of Disturbance |
LTCPU |
Long Term Control Plan Update |
MSC |
Medium Specific Concentration |
MS4 |
Municipal Separate Storm Sewer System |
NJCAT |
New Jersey Center for Advanced Technology |
NJ DEP |
New Jersey Department of Environmental Protection |
NPDES |
National Pollutant Discharge Elimination System |
NOAA |
National Oceanic and Atmospheric Administration |
NOI |
Notice of Intent |
NOT |
Notice of Termination |
NRCS |
Natural Resources Conservation Service |
O&M |
Operations and Maintenance |
OPA |
Office of Property Assessment |
OSHA |
Occupational Safety and Health Administration |
PA DEP |
Pennsylvania Department of Environmental Protection |
PCPC |
Philadelphia City Planning Commission |
PCSM |
Post-Construction Stormwater Management |
PCSMP |
Post-Construction Stormwater Management Plan |
PHS |
Public Health and Safety |
POA |
Point of Analysis |
PUD |
Planned Unit Development |
PVC |
Polyvinyl Chloride |
PWD |
Philadelphia Water Department |
RCP |
Reinforced Concrete Pipe |
ROW |
Right-of-Way |
SIU |
Significant Industrial User |
SMIP |
Stormwater Management Incentive Program |
SMP |
Stormwater Management Practice |
SPLP |
Synthetic Precipitation Leachate Procedure |
SPT |
Standard Penetration Test |
SSPA |
Steep Slope Protection Area |
SWTR |
Surface Water Treatment Rule |
TAPE |
Technology Assessment Protocol - Ecology |
TARP |
Technology Acceptance and Reciprocity Partnership |
TSS |
Total Suspended Solids |
TMDL |
Total Maximum Daily Load |
TPO |
Thermal Polyolefin |
USDA |
United States Department of Agriculture |
USEPA |
United States Environmental Protection Agency |
USGBC |
United States Green Building Council |
USGS |
United States Geological Survey |
VCP |
Vitrified Clay Pipe |
WQv |
Water Quality Volume |
WTR |
Water Transport Records |
WWO |
Wissahickon Watershed Overlay |
ZBA |
Zoning Board of Adjustments |
C. PWD Stormwater Regulations
The Philadelphia Water Department (PWD) Stormwater Regulations (Stormwater Regulations), presented in Appendix C, have been developed in accordance with Philadelphia Code §14-704(3), and they consist of four major Post-Construction Stormwater Management Requirements: Water Quality, Channel Protection, Flood Control, and Public Health and Safety Release Rate. In addition, all earth disturbance activity must comply with the Erosion and Sediment Control requirements of the Pennsylvania Department of Environmental Protection, as specified in 25 Pa. Code §102.4.
The objectives of these requirements include:
- Reduce pollution in runoff
- Recharge the groundwater table and increase stream base flows
- Restore more natural site hydrology
- Reduce combined sewer overflows (CSOs)
- Reduce the quantity, frequency and duration of CSOs
- Protect stream channels and banks, fish habitat and infrastructure from erosion and sedimentation
- Reduce or prevent flooding in areas downstream of development sites
The details of the Stormwater Regulations can be found within Chapter 6: Stormwater of the PWD Regulations:
D. Watershed Maps
Watershed location plays an important role in identifying how the Stormwater Regulations, specifically the Post-Construction Stormwater Management Requirements, are applied to a project. Once the location of the development site is determined, Appendix D may be used to evaluate its Flood Management District and sewershed. If they are unable to confirm either, the applicant should contact Stormwater Plan Review. These maps are approximations of sewershed boundaries. The applicant must refer to their project’s point of stormwater discharge when determining which requirements apply to their project.
- Citywide Watershed Map
- Darby and Cobbs Creeks
- Delaware Direct
- Lower Schuylkill River
- Pennypack Creek
- Poquessing Creek
- Tookany/Tacony-Frankford
- Wissahickon Creek
E. Plan and Report Checklists
Section 2.3 provides Review Phase Submission Package checklists as well as detailed guidance on the submission process. Appendix E includes checklists itemizing the submittal requirements of plans and reports required for Review Phase Submission Packages. By ensuring that plans and reports meet the requirements identified in each checklist, the applicant can streamline their project's Review Phase.
- Table E-1: General Plan Sheet Requirements
- Table E-2: Existing Conditions Plan Requirements
- Table E-3: Conceptual Stormwater Management Plan Requirements
- Table E-4: Erosion and Sediment Control Plan Requirements
- Table E-5: Standard Erosion and Sediment Control Notes
- Table E-6: Standard Sequence of Construction Notes
- Table E-7: Post-Construction Stormwater Management Plan Report Requirements
- Table E-8: Record Drawing Requirements
F. Design Guidance Checklists
The Philadelphia Water Department's Stormwater Plan Review Design Guidance Checklists contained in Appendix F are a supplemental list of guidelines for Regulatory compliance, plan creation, hydrologic modeling and calculations, and the design of specific stormwater management practices. They are provided to assist in the formation of both sound, compliant stormwater management designs and complete Post-Construction Stormwater Management Plan (PCSMP) submissions. The designer should use the checklists as guidance during the design and calculation stages or as useful quality assurance/quality control checks prior to PCSMP Review Phase submission.
- F.1 Stormwater Regulation Compliance
- F.2 Post-Construction Stormwater Management Plan
- F.3 Erosion and Sediment Control
- F.4 Disconnected Impervious Cover
- F.5 Infiltration Testing and Soil Assessment
- F.6 Hydrologic Model and Calculation Methods
- F.7 Bioinfiltration/Bioretention
- F.8 Porous Pavement
- F.9 Green Roofs
- F.10 Subsurface Infiltration
- F.11 Cisterns
- F.12 Blue Roofs
- F.13 Ponds and Wet Basins
- F.14 Subsurface Detention
- F.15 Media Filters
- F.16 Pretreatment
- F.17 Inlet Controls
- F.18 Outlet Controls
G. SMP Maintenance Guide Documents
Appendix G contains the SMP Maintenance Guide and its associated documents. An SMP-specific, site-specific SMP Maintenance Guide, prepared by the designer and submitted to, and reviewed by, PWD during the PCSMP Review Phase, should be provided to and implemented by the property owner as a guide for long-term operations and maintenance of the SMPs on-site. SMP Maintenance Guide instructions are available on the first page of the SMP Maintenance Guide to guide the designer through the creation of these items. The SMP Maintenance Guide must be accompanied by a Site Map and a separate Maintenance Schedule Form for each SMP to allow the property owner to track all maintenance activities for their site. SMP Maintenance Guidance One-Sheets are available for each SMP detailed in this Manual in order to provide guidance on SMP maintenance activities and frequencies, including recommended SMP maintenance schedules.
- SMP Maintenance Guide (DOC)
- SMP Maintenance Guide Site Map Sample (PDF)
- SMP Maintenance Schedule Forms (XLS)
- SMP Maintenance Guidance One-Sheets (PDF)
H. Infiltration Testing Log
Appendix H contains a template log for documenting infiltration testing results. This Infiltration Testing Log includes guidance for documenting soil characteristics and is required to be completed and submitted as part of the Geotechnical Report during the Post-Construction Stormwater Management Plan Review Phase.
I. Landscape Guidance
Native plant species are recommended over exotic foreign species because they are well adapted to local climate conditions. This will result in less replacement and maintenance, while supporting the local ecology.
A list of herbaceous trees, shrubs, and plants native to Philadelphia and Pennsylvania and suitable for planting in stormwater management facilities are included in Table I-1. The list is intended as a guide for general planting purposes and planning considerations. Knowledgeable landscape designers and nursery suppliers may provide additional information for considering specific conditions for successful plant establishment and accounting for the variable nature of stormwater hydrology. Because individual plants often have unique growing requirements difficult to convey in a general listing, it will be necessary to perform additional research to obtain specific information on the plant species proposed in order to ensure successful plant establishment.
Table I-1 lists native and recommended plants, trees, shrubs, and grasses and is organized by Type and Latin name. Additional information given for each species includes: Common name, National Wetland Indicator Status, hydrologic zone, inundation tolerance, drought tolerance, salt tolerance, mature canopy spread, mature height, light requirements, nativity, commercial availability, and notes to provide guidance for application and selection. For example, some trees are well-suited to landscaped areas that will receive stormwater runoff, while others may not tolerate the additional moisture.
National Wetland Indicator Status
The National Wetland Indicator Status (from Region 1, Reed, 1988) has been included to show “the estimated probability of a species occurring in wetlands versus non-wetlands” (Reed, 1988). Reed defines the indicator categories as follows:
- Obligate wetland (OBL): Plants which nearly always (more than 99% of the time) occur in wetlands under natural conditions.
- Facultative Wetland (FACW): Plants which usually occur in wetlands (from 67 to 99% of the time), but occasionally are found in non-wetlands.
- Facultative (FAC): Plants which are equally likely to occur in wetlands and non-wetlands, and are found in wetlands from 34 to 66% of the time.
- Facultative Upland (FACU): Plants which usually occur in non-wetlands (from 67 to 99% of the time), but occasionally are found in wetlands.
- Upland (UPL): Plants which almost always (more than 99% of the time) occur in non-wetlands under natural conditions.
- A given indicator status shown with a “+” or a “-” means that the species is more (+) or less (-) often found in wetlands than other plants with the same indicator status without the “+” or “-” designation.
Hydrologic Zones
For planting within a stormwater management practice (SMP), it is necessary to determine what hydrologic zones will be created within the SMP. Hydrologic zones describe the degree to which an area is inundated by water (the designer is referred to Figure 4.1-3 for an example of hydrologic zones in a bioinfiltration/bioretention basin). Plants have differing tolerances to inundation, and, as an aid to landscape designers, these tolerance levels have been divided into six zones and corresponding appropriate plant species have been identified. In Table I-1, each plant species has a corresponding hydrologic zone provided to indicate the most suitable planting location for successful establishment. While the most common zones for planting are listed in parentheses, the listing of additional zones indicates that a plant may survive over a broad range of hydrologic conditions. Just as plants may, on occasion, be found outside of their hardiness zone, they may also be found outside of their hydrologic zone. Additionally, hydrologic conditions in an SMP may fluctuate in unpredictable ways; thus the use of plants capable of tolerating wide varieties of hydrologic conditions greatly increases a successful planting. Conversely, plants suited for specific hydrologic conditions may perish when hydrologic conditions fluctuate, thus exposing the soil and increasing the chance for erosion.
Inundation Tolerance
Since the Wetland Indicator Status alone does not provide an indication of the depth or duration of flooding that a plant will tolerate, the “Inundation Tolerance” column is designed to provide further guidance. If a plant is capable of withstanding permanent saturation, the depth of this saturation is listed (for example, “saturated” indicates the soil can be moist at all times, “sat, 0-6”“ indicates that the species can survive in constantly moist soil conditions with up to six inches of standing water). Conversely, a plant may only tolerate seasonal inundation – such as after a storm event – or may not tolerate inundation at all. This type of plant would be well-suited for an SMP that is expected to drain quickly or in the drier zones of the SMP.
Drought Tolerance (N=none; L=low; M=medium; H=high)
The drought tolerance column is meant to provide a way for SMP designers to select appropriate native plants that can survive in hot summer conditions, with a minimum of irrigation. Drought tolerance is defined as the relative tolerance of the plant to drought conditions compared to other plants in the same region (USDA, 2005).
Salt Tolerance (N=none; L=low; M=medium; H=high; U=unknown)
This column ranks the relative tolerance of a species to salt content in the soil. If U (unknown) is displayed, no research was found for that particular species.
Mature Canopy Spread
This column gives the SMP designer a rough estimate of the diameter (or spread) of a tree species’ branching when it has matured. This information indicates what the light conditions will be like beneath the tree for understory plantings; how much space should be left open between the tree planting pit and any vertical structures, such as buildings; how far apart the trees should be planted; and it gives an idea, along with the mature height of the species, of the tree’s growth habit. The mature canopy spread also provides a rough idea for how much leaf surface area will be available to intercept stormwater before it reaches the ground.
Mature Height
This column provides the approximate mature height of plant species in optimal growing conditions. This height may be reduced dramatically in the urban environment where light, space, and other factors may not be as readily available as in a forest or field setting. However, by providing as much space as possible for a plant to grow and by choosing appropriate species for a planting area, improved – if not optimal – growing conditions can be achieved. For example, a tree planted in a sidewalk pit measuring four feet by four feet may only reach half its mature height, while a tree planted in a four-foot-wide “trough” style planting bed will grow taller and live longer, because it will have greater access to air and water.
Light Requirement
The light requirements for each species are listed as ranges between full shade and full sun. At the bottom of the range – full shade – plants thrive in conditions where they receive filtered, or dappled, light for the entire day (such as under an oak tree). In the middle of the range are plants that grow best in part shade, where they are in full shade for two to three hours during midday. Plants that require full sun should be sited so that they receive five or more hours of direct sun during the growing season. Some plants requiring full sun may still do well in a part shade environment, depending on the quality and duration of the light the plants receive when they are not in the shade.
Nativity
A native plant is an indigenous species that occurred in the region prior to settlement by the Europeans. In this column, each species is located within a range of nativity to Philadelphia. Plants known to have existed in Philadelphia County are native to Philadelphia, while a wider geographic range lists plants native to the state, but not necessarily to the county. The widest geographic range lists a few species native to the United States, but not necessarily to Pennsylvania. The plants listed that are not specifically native to Philadelphia are included because of their demonstrated success within SMPs.
Commercial Availability (C=container; P=plug; S=seed)
Wildflower and grass species often come in a form known as a plug. These are often grown and sold in trays of 50 of the same species. They are essentially very small container plants, with a root/soil mass about an inch wide and two to four inches long. Most species available in plug form are also sold as seed. Often, a combination of plugs and seed will be used to establish a SMP quickly and provide immediate visual interest and stabilization.
Container-grown plants include trees, shrubs, wildflowers, ferns, grasses, and sedges. This is an excellent alternative to the far more expensive balled-and–burlapped (B&B) form of trees and shrubs, although the size of the tree is almost always smaller. Nurseries often provide a few container sizes for each species.
Notes
PWD has included recommendations for street trees in the notes section of the native plants list and the recommended non-invasive plants, trees, shrubs, and grasses list to assist designers in selection of vegetation most appropriate for the harsh conditions which are often associated in close proximity to streets. It is likely that most of these areas will be hot in summer months until the trees become established.
Table I-1: Native and Recommended Non-invasive Plants
Table I-1 is too large to display in the browser. Download a PDF copy.
Prohibited Non-native and Invasive Plants
Invasive non-native plants reproduce rapidly, degrade, and take over natural ecosystems, and have few, if any, natural controls to keep them in check. Brought in to new areas by people for a specific purpose or by accident, these species have characteristics that allow them to grow out of control and usually favor disturbed sites like areas of new construction. Under no circumstance should they be planted in a SMP. Because of appealing characteristics, some of these plants are available for sale, and care should be taken not to purchase them. Additionally, the ability to identify and remove them before they can establish themselves is important, as they almost always invade due to their gregarious reproductive strategies. They can be especially hard to get rid of once they take hold. Table I-2 lists common invaders for the Mid-Atlantic region.
Table I-2: Common Invasive Species of the Mid-Atlantic Region
Type |
Latin Name |
Common Name |
Availability |
---|---|---|---|
forb |
Hemerocallis fulva |
Common daylily |
commercially available |
forb |
Alliaria petiolata |
Garlic mustard |
|
forb |
Polygonum cuspidatum |
Japanese knotweed |
|
forb |
Ranunculs ficaria |
Lesser celadine |
|
forb |
Lythrum salicaria |
Purple loosetrife |
|
forb |
Cirsium arvense |
Canada thistle |
|
forb |
Lespedeza cuneata |
Chinese lespedeza |
|
forb |
Heracleum mantegazzianum |
Giant hogweed |
|
forb |
Murdannia keisak |
Marsh dewflower |
|
forb |
Centaurea biebersteinii |
Spotted knapweed |
|
grass |
Bambusa, Phyllostachys, Pseudosassa |
Bamboo |
commercially available |
grass |
Microstegium vimineum |
Japanese stiltgrass |
|
grass |
Miscanthus sinensis |
Chinese silvergrass |
|
grass-like |
Phragmites australis |
Common reed |
|
grass-like |
Arundo donax |
Giant reed - wild cane |
|
shrub |
Berberis thunbergii |
Japanese barberry |
commercially available |
shrub |
Ligustrum spp. |
Privets |
commercially available |
shrub |
Euonymus alata |
Winged burning bush |
commercially available |
shrub |
Buddleja davidii |
Butterfly bush |
commercially available |
shrub |
Spiraea japonica |
Japanese spiraea - |
commercially available |
shrub |
Elaeagnus umbellata |
Autumn olive |
|
shrub |
Lonicera spp. |
Bush honeysuckles |
commercially available |
shrub |
Rosa multiflora |
Mulitflora rose |
|
shrub |
Rubus phoenicolasius |
Wineberry |
|
shrub |
Rhodotypos scandens |
Jetbead |
|
Tree |
Pyrus calleryana ‘Bradford’ |
Bradford pear |
commercially available |
Tree |
Acer platanoides |
Norway maple |
commercially available |
Tree |
Quercus acutissima |
Sawtooth oak |
commercially available |
Tree |
Paulownia tomentosa |
Princess tree |
|
Tree |
Ailanthus altissima |
Tree of Heaven |
|
Tree |
Albizia julibrissin |
Silk tree - mimosa tree |
commercially available |
Tree |
Broussonetia papyrifera |
Paper mulberry |
|
Tree |
Morus alba |
White mulberry |
|
Vine |
Hedera helix |
English Ivy |
commercially available |
Vine |
Wisteria sinensis, W. floribunda |
Wisteria, exotic |
commercially available |
Vine |
Eunonymus fortunei |
Creeping euonymus |
commercially available |
Vine |
Lonicera japonica |
Japanese honeysuckle |
commercially available |
Vine |
Pueraria montana v. lobata |
Kudzu |
|
Vine |
Polygonum perfoliatum |
Mile-a-minute |
|
Vine |
Celastrus orbiculatus |
Oriental bittersweet |
|
Vine |
Ampelopsis brevipedunculata |
Porcelain berry |
commercially available |
Vine |
Akebia quinata |
Five-leaved akebia |
|
Vine |
Cynanchum louiseae |
Louis’ swallowwort |
|
J. Construction Certification Package
It is important, both for the property owner and for the Philadelphia Water Department (PWD), to ensure that all stormwater management practices (SMPs) are constructed in strict accordance with the Approved Post-Construction Stormwater Management Plan (PCSMP). The Construction Certification Package (CCP) provides PWD with documentation that SMPs have been properly installed. Consisting of photographs, material receipts, and SMP Construction Certification Forms which must be customized by the design engineer prior to PCSMP Approval, the CCP must be kept on-site and completed by a registered professional during construction. Appendix J contains a description of the required CCP documentation and a collection of customizable SMP Construction Certification Forms to be populated with key information during construction and installation.
K. Record Drawing Sample
Along with the Construction Certification Package, the Philadelphia Water Department (PWD) requires that Record Drawing(s) be submitted at the close of the project to ensure that the stormwater management practices (SMPs) and their elements were constructed in general accordance with the Approved Post-Construction Stormwater Management Plan (PCSMP), and to document any field changes. Record Drawing(s) are required for SMP verification and are a key component of PWD’s compliance reporting. Samples which demonstrate how Approved PCSMP plan sheets should be marked-up in order to prepare Record Drawings are provided in Appendix K.
L. Standard Details
Typical construction details for several SMPs, including all of PWD’s highest-preference SMPs, such as bioinfiltration/bioretention basins, porous pavement, and green roof, and for SMP-related structures, such as cleanouts, observations wells, and outlet control structures, are available for download in AutoCAD (*.dwg) format in Appendix L. These Standard Details incorporate design specifications pursuant to each SMP’s respective design and material requirements. The designer is encouraged, not required, to use them for PCSMP creation when possible.
- Standard Details (ALL)
- Bioinfiltration/Bioretention Basin Standard Detail
- Cleanout Standard Detail
- Cleanout in Right-of-Way Standard Detail
- Double Manhole Outlet Control Structure Standard Detail
- Green Roof Standard Detail
- Observation Well Standard Detail
- Porous Pavement Standard Detail
- Riser Outlet Control Structure Standard Detail
- Subsurface Infiltration Basin (Pipe in Stone) Standard Detail
- Terraced Porous Pavement Standard Detail
- Trap with Fresh Air Inlet Standard Detail
- Underdrain Connection Standard Detail
- Underdrain Orifice Standard Detail