Flood Mitigation / Stormwater Management Plan City of Birmingham October 2004 Prepared by: URS Project Number 19613329.00200 CITY OF BIRMINGHAM FLOOD MITIGATION / STORMWATER MANAGEMENT PLAN TABLE OF CONTENTS EXECUTIVE SUMMARY 1.0 INTRODUCTION ............................................................................... 1-1 1.1 Backgroun d............................................................................. 1-1 1.2 Flood Mitigation / Stormwater Management Planning Committee................................................................ 1-2 1.3 Planning Approach ................................................................. 1-5 1.4 Agency Coordination............................................................... 1-6 1.5 Consistency with Community Rating System Floodplain Management Planning Process .............................................. 1-9 1.6 Consistency with Disaster Mitigation Act of 2000 ................... 1-11 2.0 PROBLEM DESCRIPTION ............................................................... 2-1 2.1 Sources of Flooding................................................................ 2-1 2.2 Birmingham Watersheds......................................................... 2-1 2.3 Historical Flooding .................................................................. 2-4 2.4 Flood Data .............................................................................. 2-8 2.4.1 Background................................................................... 2-8 2.4.2 Flood Hazard – Damage Relationship .......................... 2-9 2.4.3 Existing Studies and Data............................................. 2-9 2.5 Safety and Health Hazards..................................................... 2-10 2.6 Flood Prone Buildings............................................................. 2-11 2.7 Critical Facilities...................................................................... 2-13 2.8 Economic Impact .................................................................... 2-14 2.9 Other Natural Hazards............................................................ 2-15 2.10 Natural and Beneficial Floodplain Functions........................... 2-18 2.11 Future Development ............................................................... 2-19 2.12 Conclusion s ............................................................................ 2-20 3.0 GOALS.............................................................................................. 3-1 3.1 Findings from Flood Hazard Assessment ............................... 3-1 3.2 Goals ...................................................................................... 3-2 4.0 PREVENTIVE MEASURES............................................................... 4-1 4.1 Planning.................................................................................. 4-1 4.2 Open Space Preservation....................................................... 4-2 4.3 Zoning..................................................................................... 4-3 4.4 Subdivision Regulations.......................................................... 4-4 4.5 Building Codes........................................................................ 4-5 4.6 Floodplain Development Regulations ..................................... 4-6 4.7 Stormwater Management........................................................ 4-7 4.8 Conclusi ons ............................................................................ 4-8 4.9 Recommendat ions.................................................................. 4-9 i Octob er 2004 CITY OF BIRMINGHAM FLOOD MITIGATION / STORMWATER MANAGEMENT PLAN 5.0 PROPERTY PROTECTION .............................................................. 5-1 5.1 Relocation............................................................................... 5-1 5.2 Acquisition .............................................................................. 5-2 5.3 Building Elevation ................................................................... 5-3 5.4 Local Barriers.......................................................................... 5-4 5.5 Dry Flood Proofing.................................................................. 5-6 5.6 Wet Flood Proofing ................................................................. 5-7 5.7 Sewer Back-up Protection ...................................................... 5-8 5.8 Insurance................................................................................ 5-8 5.9 City’s Role............................................................................... 5-9 5.10 Conclusions ............................................................................ 5-10 5.11 Recommendations.................................................................. 5-11 6.0 EMERGENCY SERVICES ................................................................ 6-1 6.1 Flood Detection....................................................................... 6-1 6.2 Flood Warning ........................................................................ 6-2 6.3 Flood Response...................................................................... 6-3 6.4 Critical Facilities Protection..................................................... 6-4 6.5 Conclusion .............................................................................. 6-4 6.6 Recommendations.................................................................. 6-5 7.0 STRUCTURAL PROJECTS.............................................................. 7-1 7.1 Reservoirs............................................................................... 7-1 7.2 Levees .................................................................................... 7-2 7.3 Channel Modifications............................................................. 7-3 7.4 Dredging ................................................................................. 7-3 7.5 Drainage System Maintenance............................................... 7-4 7.6 Conclusions ............................................................................ 7-5 7.7 Recommendations.................................................................. 7-5 8.0 NATURAL RESOURCE PROTECTION ........................................... 8-1 8.1 Wetlands Protection................................................................ 8-1 8.2 Erosion and Sedimentation Control ........................................ 8-2 8.3 River Restoration .................................................................... 8-5 8.4 Best Management Practices ................................................... 8-6 8.5 Dumping Regulations.............................................................. 8-13 8.6 Conclusions ............................................................................ 8-13 8.7 Recommendations.................................................................. 8-14 9.0 PUBLIC INFORMATION................................................................... 9-1 9.1 Map Information...................................................................... 9-2 9.2 Library and Websites .............................................................. 9-3 9.3 Outreach Projects ................................................................... 9-3 9.4 Technical Assistance .............................................................. 9-4 ii Octob er 2004 CITY OF BIRMINGHAM FLOOD MITIGATION / STORMWATER MANAGEMENT PLAN 9.5 Real Estate Disclosure............................................................ 9-5 9.6 Educational Programs............................................................. 9-6 9.7 Conclusions ............................................................................ 9-6 9.8 Recommendations.................................................................. 9-7 10.0 FLOOD MITIGATION / STORMWATER MANAGEMENT ACTION PLAN.................................................................................. 10-1 10.1 Preventio n............................................................................... 10-2 10.1.1 Ordinance Action Items............................................... 10-2 10.1.2 Map Modernization Program....................................... 10-6 10.2 Property Protection ................................................................. 10-7 10.2.1 Property Protection Action Items................................. 10-7 10.2.2 Repetitive Loss Strategy ............................................. 10-8 10.3 Emergency Services............................................................... 10-10 10.3.1 ALERT System ........................................................... 10-10 10.3.2 Emergency Services Action Items .............................. 10-10 10.4 Structur al ................................................................................ 10-11 10.4.1 Structural Action Items................................................ 10-11 10.5 Natural Resource Protection................................................... 10-13 10.5.1 Natural Resource Protection Action Items .................. 10-13 10.6 Public Information ................................................................... 10-14 10.6.1 Public Information Plan ............................................... 10-14 10.7 Stormwater Management........................................................ 10-16 10.8 CRS Program Review and Proposed Actions......................... 10-25 10.9 Potential Funding Sources for Plan Implementation ............... 10-29 10.9.1 Federal Funding.........................................................