Stormwater Management Design Manual Table of Contents Chapter 1 INTRODUCTION 1-1 1.1 Background .......................................................................................................................... 1-1 1.2 Introduction ......................................................................................................................... 1-1 1.3 General Provisions .............................................................................................................. 1-2 1.4 Purpose ................................................................................................................................. 1-2 1.5 Chapter Overview ............................................................................................................... 1-4 1.6 Chesapeake Bay Critical Area ........................................................................................... 1-5 1.7 Maintenance and Inspection Monitoring of Constructed Facilities ............................. 1-5 1.8 General Permit for Stormwater Associated with Construction Activity .................... 1-5 1.9 NPDES Phase 1 MS4 Permit .............................................................................................. 1-6 1.10 TMDL .................................................................................................................................... 1-6 1.11 Phase II Watershed Implementation Plan ....................................................................... 1-7 Chapter 2 REPORT AND PLAN STANDARDS 2-1 2.1 General .................................................................................................................................. 2-1 2.2 General Plan Standards ...................................................................................................... 2-1 2.2.1 All Standards ............................................................................................................... 2-2 2.2.2 Digital Drawings ......................................................................................................... 2-4 2.2.3 Hand Drafting ............................................................................................................. 2-4 2.2.4 Other ............................................................................................................................. 2-4 2.3 Cover Sheet .......................................................................................................................... 2-5 2.4 Scales and Bar Scale ............................................................................................................ 2-5 2.5 Plan Notes ............................................................................................................................ 2-5 2.5.1 Label Notes .................................................................................................................. 2-6 2.5.2 Descriptive Notes ........................................................................................................ 2-6 2.5.3 General/Specification Notes ..................................................................................... 2-6 2.5.4 Certifications ................................................................................................................ 2-7 2.5.5 Miscellaneous Lettering ............................................................................................. 2-7 2.6 Legends ................................................................................................................................. 2-8 2.7 Plan Dimensioning and Leaders ....................................................................................... 2-8 2.8 Sections ............................................................................................................................... 2-10 2.9 Channel Profiles ................................................................................................................ 2-11 2.10 Details ................................................................................................................................. 2-12 2.11 Reports ................................................................................................................................ 2-12 2.11.1 Summary Tables ........................................................................................................ 2-12 2.11.2 Graphs, Charts, and Tables ...................................................................................... 2-13 2.11.3 Appendices ................................................................................................................ 2-13 Chapter 3 PERMIT PROCESSING 3-1 3.1 Stages of Plan and Permit Review .................................................................................... 3-1 3.1.1 Plan and Permit Applications and Fees ................................................................... 3-3 3.1.2 Phase One – Land Development Concept Stage Approvals ................................. 3-5 3.1.3 Phase Two – Land Development Entitlement Approvals ........................................... 3-10 3.1.4 Phase Three – Land Development Final Approvals and Permits ...................... 3-11 i Table of Contents Issue Date: September 30, 2014 Stormwater Management Design Manual Table of Contents 3.2 Plan and Permit Revisions ............................................................................................... 3-17 3.3 Updating of an Approved Plan ....................................................................................... 3-17 3.4 Special Drain Permits ....................................................................................................... 3-17 3.5 As-Built Plan Approval .................................................................................................... 3-18 3.6 Other Agency Permits and Coordination ...................................................................... 3-18 Chapter 4 100-YEAR FLOODPLAIN 4-1 4.1 Introduction ......................................................................................................................... 4-1 4.2 Authority of Jurisdiction .................................................................................................... 4-1 4.2.1 Prince George’s County.............................................................................................. 4-1 4.2.2 FEMA Program............................................................................................................ 4-2 4.3 Acceptable Studies .............................................................................................................. 4-3 4.4 Allowable Floodplain Impacts .......................................................................................... 4-4 4.5 Permitting Floodplain Impacts ......................................................................................... 4-5 4.6 Delineation of Floodplain - GIS-based Floodplain Submittals ..................................... 4-5 4.7 Delineation of Floodplain - Previously Approved Studies: .......................................... 4-7 4.8 Delineation of Floodplain - FEMA Floodplains .............................................................. 4-7 4.9 Delineation of Floodplain - Private Consultant Engineering Studies ......................... 4-7 4.9.1 Data Required for Private Consultant Engineering Studies ................................. 4-9 4.9.2 Conservative 100 Year Floodplain Delineation .................................................... 4-19 4.10 Floodplain Fill .................................................................................................................... 4-20 4.11 Floodplain Buffer .............................................................................................................. 4-20 4.12 Floodplain Easements ....................................................................................................... 4-21 4.13 Floodplain and Net Tract Area ....................................................................................... 4-21 Chapter 5 SITE DEVELOPMENT CONCEPT PLAN 5-1 5.1 Purpose, Jurisdiction, and Process.................................................................................... 5-1 5.1.1 Purpose and Jurisdiction ............................................................................................ 5-1 5.1.2 The MDE’s Three-Phase Comprehensive Review Process .................................... 5-1 5.1.3 First Phase – Site Development Concept Plan ........................................................ 5-2 5.1.4 Exemptions ................................................................................................................... 5-3 5.1.5 Variance ........................................................................................................................ 5-4 5.1.6 Standard Concept Plan ............................................................................................... 5-5 5.1.7 Alternate Requirements for Chesapeake Bay Critical Area .................................. 5-5 5.1.8 Administrative Waivers and Exemptions ............................................................... 5-6 5.2 Concept Design Phase – Definition, Design Guidance, Planning Steps ...................... 5-8 5.2.1 ESD – Definition .......................................................................................................... 5-8 5.2.2 ESD - Design Guidance 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