4/7/2010 - Review Public For - Draft This page left blank intentionally. 4/7/2010 - Review Public For - Draft TABLE OF CONTENTS Part I Section I – Introduction Rainfall and Stormwater Runoff .............................................................................................................................. I-1 Watershed Hydrology............................................................................................................................................... I-2 Stormwater Management Planning ...................................................................................................................... I-3 Section II – Goals and Objectives of the Act 167 Stormwater Management Plan Stormwater Planning and the Act 167 Process................................................................................................... II-1 Plan Advisory Committees...................................................................................................................................... II-1 Goals and Objectives of the Plan ......................................................................................................................... II-3 Section III – County Description Political Jurisdictions.................................................................................................................................................III-1 Land Use ....................................................................................................................................................................III-1 Climate.......................................................................................................................................................................III-3 Geology .....................................................................................................................................................................III-3 Slopes .........................................................................................................................................................................III-5 4/7/2010 Soils..............................................................................................................................................................................III-5 - Water Resources.......................................................................................................................................................III-7 Surface Water Quality .............................................................................................................................................III-8 Floodplain Data........................................................................................................................................................III-9 Section IV – Existing Stormwater Regulations and Related Plans Existing Federal Regulations ..................................................................................................................................IV-1 Existing State Regulations.......................................................................................................................................IV-2 Existing Municipal Regulations ..............................................................................................................................IV-3 Review Existing Related Plans..............................................................................................................................................IV-5 Section V – Significant Problem Areas and Obstructions Identification of Problem Areas and Obstructions.............................................................................................V-1 Hydraulic Modeling..................................................................................................................................................V-5 Problem Area Assessment ......................................................................................................................................V-6 Recommendations ................................................................................................................................................V-11 Public Section VI – Technical Analysis – Modeling Technical Approach...............................................................................................................................................VI-1 Hydrologic Model Preparation .............................................................................................................................VI-1 For Hydrologic Model Parameters..............................................................................................................................VI-5 - Model Calibration ...................................................................................................................................................VI-8 Modeling Results....................................................................................................................................................VI-10 Stormwater Management Districts.....................................................................................................................VI-13 Section VII – Technical Standards and Criteria for Control of Stormwater Runoff Technical Standards for Stormwater Management ........................................................................................VII-1 Draft Criteria for Control of Stormwater Runoff...........................................................................................................VII-2 Recommended Best Management Practices..................................................................................................VII-5 Implementation of Stormwater Management Controls .................................................................................VII-9 Section VIII - Economic Impact of Stormwater Management Standards Implementation of Stormwater Standards .......................................................................................................VIII-1 Design Example(s).................................................................................................................................................VIII-1 Economic Impact of Stormwater Management Standards .........................................................................VIII-6 Montour County Act 167 Stormwater Management Plan, Phase II (i) Section IX – Water Quality Impairments and Recommendations Impaired Streams .................................................................................................................................................... IX-1 Critical Sources of Impairment.............................................................................................................................. IX-3 Agricultural ............................................................................................................................................................... IX-3 Recommendations ................................................................................................................................................. IX-4 TMDL Discussion ....................................................................................................................................................... IX-8 Section X – Additional Recommendations Municipal Zoning ......................................................................................................................................................X-1 River Corridor Protection ........................................................................................................................................X-2 Low Impact Development Site Design.................................................................................................................X-6 Summary ....................................................................................................................................................................X-9 Section XI – Plan Implementation and Update Procedures Plan Review and Adoption ................................................................................................................................... XI-1 Implementation of the Plan................................................................................................................................... XI-2 Procedure for Updating the Plan ......................................................................................................................... XI-3 Section XII – Works Cited Part II 4/7/2010 Model Ordinance - LIST OF PLATES 1. Base Map 2. Existing Land Use 3. Future Land Use Review 4. Hydrologic Soils 5. Digital Elevation Model 6. Geology 7. Problem Areas, Obstructions, and SWM Facilities 8. Flood Control Structures and Problem Areas 9. Floodplains Public 10. Stormwater Management Districts For LIST OF APPENDICES - Appendix A – Watershed Modeling Technical Data Appendix B – Supporting Calculations for Design Example(s) Appendix C – Significant Problem Area Modeling and Recommendations Draft Appendix D – Natural Resource Activities Impacting Stormwater Runoff Montour County Act 167 Stormwater Management Plan, Phase II (ii) Draft Model Stormwater Management Ordinance Montour County Act 167 County-Wide 4/7/2010 Stormwater Management Plan - March 2010 Review Public For - Draft 130 Buffalo Road• Lewisburg, Pennsylvania 17837 • 570.524.6744 [phone] Using The Model