1. Appendix A - Water Quality
    2. Appendix B - Pennsylvania Native Plant List
    3. Appendix C - Protocols for Structural BMPs
    4. Protocol 1 – Site Evaluation and Soil Infiltratio
    5. Protocol 2 – Soil Evaluation and Investigation fo
    6. Appendix D - Stormwater Calculations and Methodo
    7. Glossary

DEPARTMENT OF ENVIRONMENTAL PROTECTION
Bureau of Watershed Management
DOCUMENT NUMBER:
363-0300-002
TITLE:
Pennsylvania Stormwater Best Management Practices Manual
EFFECTIVE DATE:
December 30, 2006
AUTHORITY:
Pennsylvania Clean Streams Law (35 P.S. §§ 691.1-691.1001);
Pennsylvania Stormwater Act (32 P.S. §§ 680.1-680.17); Federal
Clean Water Act (33 U.S.C.A. § 1342), 40 CFR Part 122 and 25 Pa
Code Chapters 92, 93, 102, 105 and 111.
POLICY:
The Department will ensure that activities and plans approved under
its authority will employ stormwater management plans utilizing best
management practices to control the volume, rate and water quality of
post construction stormwater runoff so as to protect and maintain the
chemical, physical and biological properties of waters of the
Commonwealth. These best management practices must, at a
minimum, protect and maintain water resources, preserve water
supplies, maintain stream base flows, preserve and restore the flood
carrying capacity of waters, preserve to the maximum extent
practicable the natural stormwater runoff regimes and natural course,
current and cross section of waters of the Commonwealth, and protect
and conserve ground waters and ground-water recharge areas.
PURPOSE:
Clean, reliable water resources are critical for sustaining the
environmental health of our natural resources, protecting the public’s
health and safety, and maintaining the economic vitality of the
Commonwealth. The purpose of this guidance manual is to ensure
effective stormwater management to minimize the adverse impacts of
stormwater on ground water and surface water resources to support
and sustain the social, economic and environmental quality of the
Commonwealth.
APPLICABILITY:
This guidance applies to all persons conducting or planning to conduct
activities that require a written post-construction stormwater
management plan.
DISCLAIMER:
The policies and procedures outlined in this guidance are intended to
supplement existing requirements. Nothing in the policies or
procedures shall affect regulatory requirements. The guidelines herein
are not an adjudication or a regulation. The Department reserves the
discretion to vary from this guidance as circumstances warrant.
363-0300-002 / December 30, 2006

PAGE LENGTH:
642
LOCATION:
Volume 34, Tab 20
DEFINITIONS:
See Title 25 Pa. Code, Chapters 92, 93, 102, 105 and 111.
363-0300-002 / December 30, 2006

Pennsylvania Stormwater
Best Management Practices
Manual
December 2006
363-0300-002 / December 30, 2006

Table of Contents
Foreword
Chapter 1
Introduction and Purpose
1.1 Purpose of This Manual ................................................................................................................1
1.2 How to Use This Manual ...............................................................................................................1
1.3 Overview of Pennsylvania’s Existing Stormwater Management Program.....................................3
Chapter 2 Making The Case For Stormwater Management
2.1 A Brief Review of Stormwater Problems in Pennsylvania.............................................................1
2.2 The Hydrologic Cycle and The Effects of Development................................................................4
2.2.1
Rainfall, Runoff, and Flooding ...............................................................................6
2.2.2
The Impacts of Vegetation Loss and Soil Changes.............................................10
2.2.3
Groundwater Recharge, Stream Base Flow, and First Order Streams ...............10
2.2.4
Stream Channel Changes ...................................................................................13
2.2.5
Water Quality ......................................................................................................14
2.3 References..................................................................................................................................19
Chapter 3 Stormwater Management Principles and Recommended
Control Guidelines
3.1 Introduction ...................................................................................................................................1
3.2 Recommended Site Control Guidelines ........................................................................................1
3.3 Recommended Volume Control Guidelines ..................................................................................2
3.3.1
Volume Control Criteria .........................................................................................4
3.3.2
Volume Control Alternatives ..................................................................................5
3.3.3
Volume Control Guideline 1...................................................................................6
3.3.4
Volume Control Guideline 2………………………………………………………….…7
3.3.5
Retention and Detention Considerations...............................................................7
3.4 Recommended Peak Rate Control Guideline ...............................................................................8
3.5 Recommended Water Quality Control Guideline ..........................................................................8
3.6 Stormwater Standards for Special Areas ......................................................................................9
Chapter 4 Integrating Site Design and Stormwater Management
4.1 A Recommended Site Design Procedure for Comprehensive Stormwater
Management .................................................................................................................................1
4.2 The Site Design Checklist for Comprehensive Stormwater Management ....................................3
4.3 Importance of Site Assessment ....................................................................................................7
4.3.1.
Background Site Factors .......................................................................................7
4.3.2.
Site Factors Inventory ...........................................................................................8
4.3.3.
Site Factors Analysis .............................................................................................8
363-0300-002 / December 30, 2006

Chapter 5
Non-Structural BMPs
5.1 Introduction ...................................................................................................................................1
5.2 Non-Structural Best Management Practices .................................................................................1
5.3 Non-Structural BMPs and Stormwater Methodological Issues .....................................................3
5.4 Protect Sensitive and Special Value Resources ...........................................................................5
BMP 5.4.1 Protect Sensitive and Special Value Features.......................................................7
BMP 5.4.2 Protect/Conserve/Enhance Riparian Areas .........................................................13
BMP 5.4.3 Protect/Utilize Natural Flow Pathways in Overall Stormwater Planning
and Design...........................................................................................................21
5.5 Cluster and Concentrate ............................................................................................................27
BMP 5.5.1 Cluster Uses at Each Site; Build on the Smallest Area Possible.........................29
BMP 5.5.2 Concentrate Uses Areawide through Smart Growth Practices............................37
5.6 Minimize Disturbance and Minimize Maintenance .....................................................................47
BMP 5.6.1 Minimize Total Disturbed Area – Grading ...........................................................49
BMP 5.6.2 Minimize Soil Compaction in Disturbed Areas.....................................................57
BMP 5.6.3 Re-Vegetate and Re-Forest Disturbed Areas, Using Native Species .................63
5.7 Reduce Impervious Cover..........................................................................................................69
BMP 5.7.1 Reduce Street Imperviousness ..........................................................................71
BMP 5.7.2 Reduce Parking Imperviousness........................................................................77
5.8 Disconnect / Distribute / Decentralize ........................................................................................82
BMP 5.8.1 Rooftop Disconnection ........................................................................................85
BMP 5.8.2 Disconnection from Storm Sewers .....................................................................89
5.9 Source Control ...........................................................................................................................92
BMP 5.9.1 Streetsweeping....................................................................................................95
Chapter 6
Structural BMPs
6.1 Introduction ...................................................................................................................................1
6.2 Groupings of Structural BMPs.......................................................................................................1
6.3 Manufactured Products .................................................................................................................2
6.4 Volume/Peak Rate Reduction by Infiltration BMPs .......................................................................5
BMP 6.4.1 Pervious Pavement with Infiltration Bed ................................................................7
BMP 6.4.2 Infiltration Basin...................................................................................................27
BMP 6.4.3 Subsurface Infiltration Bed ..................................................................................33
BMP 6.4.4 Infiltration Trench.................................................................................................41
BMP 6.4.5 Rain Garden/Bioretention ...................................................................................49
BMP 6.4.6 Dry Well / Seepage Pit ........................................................................................67
BMP 6.4.7 Constructed Filter ................................................................................................71
BMP 6.4.8 Vegetated Swale .................................................................................................83
BMP 6.4.9 Vegetated Filter Strip...........................................................................................99
BMP 6.4.10 Infiltration Berm & Retentive Grading ..............................................................113
363-0300-002 / December 30, 2006

6.5 Volume/Peak Rate Reduction BMPs ........................................................................................123
BMP 6.5.1 Vegetated Roof..................................................................................................125
BMP 6.5.2 Runoff Capture & Reuse ...................................................................................139
6.6 Runoff Quality/Peak Rate BMPs...............................................................................................149
BMP 6.6.1 Constructed Wetland .........................................................................................151
BMP 6.6.2 Wet Pond/Retention Basin ................................................................................163
BMP 6.6.3 Dry Extended Detention Basin ..........................................................................173
BMP 6.6.4 Water Quality Filters & Hydrodynamic Devices.................................................183
6.7 Restoration BMPs .....................................................................................................................189
BMP 6.7.1 Riparian Buffer Restoration ...............................................................................191
BMP 6.7.2 Landscape Restoration......................................................................................211
BMP 6.7.3 Soil Amendment & Restoration .........................................................................221
BMP 6.7.4 Floodplain Restoration.......................................................................................231
6.8 Other BMPs and Related Structural Measures .........................................................................241
BMP 6.8.1 Level Spreader ..................................................................................................243
BMP 6.8.2 Special Detention Areas - Parking Lot, Rooftop ................................................253
Chapter 7 Special Management Areas
7.1 Introduction ...................................................................................................................................1
7.2 Brownfields....................................................................................................................................1
7.2.1 Site Remediation (i.e. Cleanup) ...........................................................................................2
7.2.2 Site Redevelopment.............................................................................................................2
7.3 Highways and Roads ....................................................................................................................3
7.3.1 Roadway Runoff Quality Issues ...........................................................................................4
7.3.2 BMP Considerations for Roadways .....................................................................................5
7.3.3 Specific BMP Considerations...............................................................................................9
7.3.4 Gravel Roads .....................................................................................................................10
7.4 Karst Areas .................................................................................................................................11
7.4.1 The Nature of Karst............................................................................................................11
7.4.2 Infiltration vs non-infiltration ...............................................................................................12
7.4.3 Basic Principles..................................................................................................................13
7.4.4 BMP Considerations ..........................................................................................................15
7.5 Mined Lands................................................................................................................................16
7.6 Stormwater Management Close to Water Supply Wells .............................................................17
7.7 Surface Water Supplies and Special Protection Waters .............................................................20
7.8 Urban Areas................................................................................................................................21
7.8.1 Highly Impervious Urban Land...........................................................................................21
7.8.2 Urban Water Quality...........................................................................................................22
7.8.3 Other Urban Stormwater Management Considerations .....................................................24
7.9 References..................................................................................................................................25
363-0300-002 / December 30, 2006

Chapter 8 Stormwater Calculations and Methodology
8.1 Introduction to Stormwater Methodologies....................................................................................1
8.2 Existing Methodologies for Runoff Volume Calculations and their Limitations..............................1
8.2.1
Runoff Curve Number Method...............................................................................1
8.2.2
Small Storm Hydrology Method.............................................................................2
8.2.3
Infiltration Models for Runoff Calculations .............................................................3
8.3 Existing Methodologies for Peak Rate/Hydrograph Estimations and their Limitations..................3
8.3.1
The Rational Method .............................................................................................3
8.3.2
SCS (NRCS) Unit Hydrograph Method..................................................................4
8.4 Computer Models..........................................................................................................................4
8.4.1
HEC Hydrologic Modeling System (HEC-HMS) ....................................................4
8.4.2
SCS/NRCS Models: WIN TR-20 and WIN TR-55..................................................5
8.4.3
EFH2 .....................................................................................................................5
8.4.4
Storm Water Management Model (SWMM)...........................................................5
8.4.5
Source Loading and Management Model (SLAMM) .............................................6
8.5 Precipitation Data for Stormwater Calculations.............................................................................6
8.6 Stormwater Quality Management..................................................................................................7
8.6.1
Analysis of Water Quality Impacts from Developed Land.....................................8
8.6.2
Analysis of Water Quality Benefits from BMPs....................................................10
8.6.3
Water Quality Analysis.........................................................................................12
8.7 Guidance for Stormwater Calculations for CG1 and CG2...........................................................13
8.7.1
Stormwater Calculation Process..........................................................................14
8.7.1.1 For Control Guideline 1 (Flow Chart B) ...................................................14
8.7.1.2 For Control Guideline 2 (Flow Chart C) ..................................................15
8.7.2
Water Quality Calculations (Flow Chart D)..........................................................16
8.8 Non-structural BMP Credits ......................................................................................................17
8.9 References and Additional Sources............................................................................................45
363-0300-002 / December 30, 2006

 
363-0300-002 / December 30, 2006
Chapter 9 Case Studies: Innovative Stormwater Management
Approaches and Practices
9.1 Introduction ...................................................................................................................................1
9.2 Outline of Information Needed for Case Studies...........................................................................2
9.3 Case Studies.................................................................................................................................3
Case Study 1: Penn State University - Centre County Visitor Center, Centre County.................3
Case Study 2: Dennis Creek Streambank Restoration, Franklin County...................................10
Case Study 3: Commerce Plaza III, Lehigh County...................................................................11
Case Study 4: Flying J. Truck Plaza for Welsh Oil of Indiana Truck Refueling
Terminal ...............................................................................................................................13
Case Study 5: Ephrata Performing Arts Center, Lancaster County ..........................................16
Case Study 6: Lebanon Valley Agricultural Center, Lebanon County........................................18
Case Study 7: Penn State University Berks County Campus, Berks County.............................19
Case Study 8: Warm Season Meadows at Williams Transco, Chester County .........................22
Case Study 9: Hills of Sullivan Residential Subdivision, Chester County ..................................24
Case Study 10: Applebrook Golf Course Community, Chester County ......................................28
Case Study 11: Swan Lake Drive Development, Delaware County............................................30
Appendix A - Water Quality
Appendix B - Pennsylvania Native Plant List
Appendix C - Protocols for Structural BMPs
Protocol 1 – Site Evaluation and Soil Infiltration Testing
Protocol 2 – Soil Evaluation and Investigation for Infiltration BMPs
Appendix D - Stormwater Calculations and Methodology – Case Study
Glossary

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