National Flood Insurance Program (NFIP) Floodplain Management Requirements: A Study Guide and Desk Reference for Local Officials TABLE OF CONTENTS Unit O: Orientation A. Introduction..............................................................................................O-3 Study guide objectives............................................................................O-4 B. Study guide materials...............................................................................O-5 Notebook.................................................................................................O-5 Flood insurance study and maps.............................................................O-6 Learning Checks.....................................................................................O-6 C. Using the Study Guide.............................................................................O-7 Where to get help....................................................................................O-7 D. Acknowledgments....................................................................................O-8 Illustrations.............................................................................................O-8 Unit 1: Floods and Floodplain Management Introduction..............................................................................................1-4 A. Floods and Floodplains.............................................................................1-5 Riverine Flooding....................................................................................1-6 Overbank flooding..............................................................................1-7 Flash flooding.....................................................................................1-8 Riverine erosion..................................................................................1-8 Coastal flooding.......................................................................................1-9 Coastal storms.....................................................................................1-9 Coastal erosion..................................................................................1-10 Tsunamis................................................................................................1-11 Lake flooding....................................................................................1-11 Shallow Flooding...................................................................................1-11 Sheet flow.........................................................................................1-11 Ponding.............................................................................................1-12 Urban drainage..................................................................................1-12 Special Flood Hazards...........................................................................1-12 Closed basin lakes.............................................................................1-13 Uncertain flow paths.........................................................................1-13 Dam breaks.......................................................................................1-14 Ice jams.............................................................................................1-15 Mudflow............................................................................................1-15 Natural and beneficial floodplain functions...........................................1-16 Natural flood and erosion control.....................................................1-17 Biologic resources and functions......................................................1-17 Societal resources and functions.......................................................1-17 B. Floodplain Development.........................................................................1-19 Floodplain Development Dynamics......................................................1-19 Riverine floodplains..........................................................................1-19 Watersheds........................................................................................1-20 Coasts................................................................................................1-21 Flood Damage........................................................................................1-22 Hydrodynamic forces........................................................................1-22 Debris impact....................................................................................1-24 Hydrostatic forces.............................................................................1-25 Soaking..............................................................................................1-25 Sediment and contaminants...............................................................1-26 Safety and Health Hazards.....................................................................1-27 C. Floodplain Management..........................................................................1-28 Evolution................................................................................................1-28 The Unified National Program for Floodplain Management.................1-29 Strategies and tools...........................................................................1-30 Floodplain Management Strategies........................................................1-30 Strategy 1: Modify human susceptibility to flood damage...............1-30 Strategy 2: Modify the impact of flooding.......................................1-31 Strategy 3: Modify flooding itself.....................................................1-31 Strategy 4: Preserve and restore natural resources...........................1-32 Unit 2: The National Flood Insurance Program A. History.......................................................................................................2-3 B. How the NFIP Works................................................................................2-6 Mapping...................................................................................................2-6 Insurance..................................................................................................2-7 Regulations..............................................................................................2-8 C. Roles and Responsibilities........................................................................2-9 The community role.................................................................................2-9 The state role............................................................................................2-9 The federal role......................................................................................2-10 D. Community Participation........................................................................2-12 Joining the NFIP....................................................................................2-12 Compliance............................................................................................2-13 Probation...........................................................................................2-14 Suspension........................................................................................2-14 Sanctions for non-participation..............................................................2-15 Unit 3: NFIP Flood Studies and Maps A. NFIP Flood Studies...................................................................................3-3 Flood Study Terminology........................................................................3-3 The base flood.....................................................................................3-3 The 100-year flood..............................................................................3-4 Special flood hazard area and base flood elevation............................3-4 Identifying Floodprone Areas..................................................................3-5 Flood Insurance Study........................................................................3-7 Flood County, USA and Incorporated Areas......................................3-8 B. Riverine Studies........................................................................................3-9 Hydrology................................................................................................3-9 Cross Sections........................................................................................3-10 Hydraulics..............................................................................................3-12 Flood Profile..........................................................................................3-13 Floodplain Map......................................................................................3-16 Floodway Analysis.................................................................................3-17 C. Coastal Flood Studies..............................................................................3-20 Storm Surge...........................................................................................3-20 Waves.....................................................................................................3-20 Hydraulic Analysis.................................................................................3-21 Coastal High Hazard Area.....................................................................3-22 Coastal Floodplain Map.........................................................................3-22 D. Shallow flooding studies.........................................................................3-24 E. Approximate Studies...............................................................................3-25 F. NFIP Maps...............................................................................................3-26 General Map Features............................................................................3-26 Map Index..............................................................................................3-27 Title block.........................................................................................3-27 Map revision date..............................................................................3-27 Map scales and north direction.........................................................3-28 Elevation reference marks.................................................................3-28 FIRM Zones......................................................................................3-29 Flood Hazard Boundary Map (FHBM)..................................................3-30 Flood Insurance Rate Map (FIRM) — old format (Pre 1986)...............3-30 Flood Boundary and Floodway Map (Floodway Map) – Old format (Pre 1986)......................................................................................................3-31 Flood Insurance Rate Map — new format (Since 1986).......................3-33 Partial Map Initiatives FIRM.................................................................3-35 FIRMs with Coastal and Lake Floodplains...........................................3-35 Coastal FIRMs..................................................................................3-35 Coastal Barrier Resources System....................................................3-35 Lakes.................................................................................................3-36 Shallow Flooding FIRMs.......................................................................3-37 FIRMs with Flood Protection Projects..................................................3-37 Countywide FIRMs................................................................................3-38 Digital FIRMs........................................................................................3-40 Digital Flood Insurance Rate Map (DFIRM)....................................3-40 Q3 Flood Data...................................................................................3-42 Unit 4: Using NFIP Studies and Maps A. Using FIS Reports.....................................................................................4-3 FIS Report Contents.................................................................................4-3 Using Flood Data and Tables...................................................................4-4 Flood discharges.................................................................................4-4 Floodway Data Table..........................................................................4-5 Coastal and Lake Elevations....................................................................4-6 Relating Report Data to Maps and Profiles.............................................4-7 B. Using the Flood Maps...............................................................................4-9 Locating a Site.........................................................................................4-9 Determining Stationing..........................................................................4-10 Base Flood Elevations from Maps.........................................................4-11 Locating the Floodway Boundary..........................................................4-11 C. Using Profiles..........................................................................................4-13 Profile Features......................................................................................4-13 Determining Base Flood Elevations......................................................4-14 Profiles..............................................................................................4-14 Other types of floodplains.................................................................4-15 Relating flood elevations to the ground............................................4-15 Relating Profiles to Maps.......................................................................4-16 D. Maintaining and Revising NFIP Maps....................................................4-17 Ordering Maps.......................................................................................4-17 Changing NFIP Maps............................................................................4-17 Types of Changes...................................................................................4-19 Maps and Letters....................................................................................4-20 Requesting Map Changes......................................................................4-22 Unit 5: The NFIP Floodplain Management Requirements A. The NFIP’s Regulations............................................................................5-4 NFIP Regulations.....................................................................................5-4 Community Types....................................................................................5-6 B. Maps and Data...........................................................................................5-8 NFIP Maps and Data................................................................................5-8 When FIRM and Ground Data Disagree.................................................5-9 Regulating Approximate A Zones.........................................................5-10 Small developments..........................................................................5-11 Larger developments.........................................................................5-12 Draft Revised NFIP Data.......................................................................5-14 Advisory Flood Hazard Data.................................................................5-15 C. Permit Requirements...............................................................................5-17 Development Permit..............................................................................5-17 Building permits................................................................................5-18 Small projects....................................................................................5-18 Permits from Other Agencies.................................................................5-19 D. Encroachments........................................................................................5-21 Regulatory Floodways...........................................................................5-21 Encroachment Review...........................................................................5-21 Streams without Floodway Maps...........................................................5-24 Allowable increases in Flood Heights...................................................5-25 E. New Buildings in A Zones Buildings.....................................................5-27 Elevation................................................................................................5-27 Fill.....................................................................................................5-27 Piles, posts, piers or columns............................................................5-28 Walls or crawlspace..........................................................................5-29 How high?.........................................................................................5-31 Elevation Certificate.........................................................................5-32 Enclosures..............................................................................................5-32 Openings...........................................................................................5-33 Use....................................................................................................5-36 Floodproofing........................................................................................5-38 How high?.........................................................................................5-39 Basements..............................................................................................5-40 Basement Exceptions.............................................................................5-40 Basements and LOMR-F Areas.............................................................5-41 Anchoring..............................................................................................5-42 Flood-Resistant Material........................................................................5-43 Accessory Structures..............................................................................5-44 Manufactured Homes.............................................................................5-45 Elevation...........................................................................................5-45 Anchoring..........................................................................................5-47 Recreational Vehicles............................................................................5-48 AO and AH Zones.................................................................................5-49 A99 and AR Zones.................................................................................5-49 F. New Buildings in V Zones......................................................................5-51 Building Location..................................................................................5-51 Elevation on Piles or Columns...............................................................5-51 Wind and water loads........................................................................5-52 Certification......................................................................................5-54 Breakaway Walls...................................................................................5-54 Coastal AE Zones..................................................................................5-56 G. Other Requirements................................................................................5-57 Subdivisions...........................................................................................5-57 Water and Sewer Systems......................................................................5-58 Watercourse alterations..........................................................................5-58 Unit 6: Additional Regulatory Measures Introduction..............................................................................................6-4 A. Taking.......................................................................................................6-5 B. State Regulatory Standards.......................................................................6-9 C. Higher Regulatory Standards..................................................................6-11 Location Restrictions.............................................................................6-12 Highly hazardous areas.....................................................................6-12 Subdivision design............................................................................6-12 Setbacks............................................................................................6-14 Manufactured homes.........................................................................6-15 Natural areas.....................................................................................6-15 Low-density zoning...........................................................................6-15 Bulding Requirements...........................................................................6-16 Freeboard..........................................................................................6-16 Foundation standards........................................................................6-17 Safety Requirements..............................................................................6-18 Critical facilities................................................................................6-18 Hazardous materials..........................................................................6-19 Dry land access.................................................................................6-19 Encroachment Standards........................................................................6-20 Compensatory Storage...........................................................................6-21 Stormwater Management.......................................................................6-22 Temporary Moratorium.........................................................................6-23 D. Flood Hazards of Special Concern..........................................................6-24 Coastal Erosion......................................................................................6-24 Regulatory standards.........................................................................6-25 Tsunamis................................................................................................6-25 Regulatory standards.........................................................................6-25 Closed Basin Lakes................................................................................6-26 Regulatory standards.........................................................................6-26 Uncertain Flow Paths.............................................................................6-27 Regulatory standards.........................................................................6-27 Dam Breaks............................................................................................6-28 Regulatory standards.........................................................................6-28 Ice Jams..................................................................................................6-29 Regulatory standards.........................................................................6-29 Mudflows...............................................................................................6-29 Regulatory standards.........................................................................6-29 E. Environmental Protection Measures........................................................6-31 Strategies................................................................................................6-31 Federal Regulations...............................................................................6-32 Wetland Protection.................................................................................6-32 Rare and Endangered Species................................................................6-33 On-site Sewage Disposal.......................................................................6-33 Facilities Siting......................................................................................6-33 Water Quality Regulations.....................................................................6-33 Special Designations..............................................................................6-34 Unit 7: Ordinance Administration Introduction..............................................................................................7-4 A. The Ordinance...........................................................................................7-5 Statutory Authority..................................................................................7-5 Types of ordinances.................................................................................7-6 Zoning ordinance................................................................................7-6 Building codes.....................................................................................7-7 Subdivision regulations.......................................................................7-9 Sanitary regulations.............................................................................7-9 “Stand alone” ordinance......................................................................7-9 Contents.................................................................................................7-10 B. The Administrator...................................................................................7-12 Duties.....................................................................................................7-12 Qualifications.........................................................................................7-15 Training..................................................................................................7-15 Liability..................................................................................................7-17 C. Development Permits..............................................................................7-20 When a permit is required......................................................................7-20 Exemptions............................................................................................7-22 Permit Application Form.......................................................................7-22 Application Review...............................................................................7-23 Review for Completeness......................................................................7-23 Review for Compliance.........................................................................7-26 Application Approval or Denial.............................................................7-28 D. Inspections..............................................................................................7-36 First Inspection.......................................................................................7-36 Second Inspection..................................................................................7-36 Checking elevations..........................................................................7-37 Third Inspection.....................................................................................7-38 Certificate of occupancy...................................................................7-38 Later Inspections....................................................................................7-39 E. Enforcement............................................................................................7-40 Voluntary Compliance...........................................................................7-40 Administrative Steps..............................................................................7-40 Legal Recourses.....................................................................................7-41 Section 1316...........................................................................................7-42 F. Appeals, Special Uses and Variances......................................................7-44 Appeals..............................................................................................7-44 Special uses.......................................................................................7-44 Variances...........................................................................................7-44 Boards...............................................................................................7-44 Variances................................................................................................7-45 NFIP requirements............................................................................7-45 Historic buildings..............................................................................7-54 Functionally dependent use...............................................................7-54 Records..............................................................................................7-55 G. Records....................................................................................................7-56 Permit File..............................................................................................7-56 Elevation Certificate..............................................................................7-57 Floodproofing Certificate.......................................................................7-58 V Zone Certification..............................................................................7-59 No-rise Certification..............................................................................7-59 Biennial Report......................................................................................7-60 Unit 8: Substantial Improvement and Substantial Damage Introduction..............................................................................................8-3 A. Substantial Improvement..........................................................................8-4 Projects affected.......................................................................................8-4 Post-FIRM buildings...........................................................................8-5 The Formula.............................................................................................8-5 Market value.......................................................................................8-6 Substantial Improvement Examples......................................................8-10 Example 1. Minor rehabilitation.......................................................8-10 Example 2. Substantial rehabilitation...............................................8-11 Example 3. Lateral addition—residential.........................................8-12 Example 4. Lateral addition—nonresidential...................................8-13 Example 5. Vertical addition—residential........................................8-14 Example 6. Vertical addition—nonresidential..................................8-15 Example 7. Post-FIRM building—minor addition...........................8-16 Example 8. Post-FIRM building—substantial improvement............8-17 B. Substantial Damage.................................................................................8-18 Cost to Repair........................................................................................8-18 Substantial Damage Examples...............................................................8-20 Example 1. Reconstruction of a destroyed building.........................8-20 Example 2. Substantially damaged structure....................................8-21 Substantial Damage Software................................................................8-22 Increased Cost of Compliance...............................................................8-22 C. Special Situations....................................................................................8-25 Exempt Costs.........................................................................................8-25 Historic Structures.................................................................................8-25 Corrections of Code Violations.............................................................8-26 Example............................................................................................8-27 Unit 9: Flood Insurance and Floodplain Management A. Flood Insurance Policies...........................................................................9-3 Who’s Involved........................................................................................9-3 Coverage..................................................................................................9-3 Building coverage...............................................................................9-3 “Building” defined..............................................................................9-4 Contents coverage...............................................................................9-5 Basements...........................................................................................9-5 Enclosures...........................................................................................9-6 Amount of coverage............................................................................9-6 Waiting period.....................................................................................9-7 The Mandatory Purchase Requirement...............................................9-7 Where it applies..................................................................................9-8 How it works.......................................................................................9-8 B. Rating Buildings......................................................................................9-11 Rating pre-FIRM buildings....................................................................9-11 Rating New Buildings............................................................................9-14 Submit for rate..................................................................................9-19 Elevation certificates.........................................................................9-19 Floodproofing....................................................................................9-19 Rating Unnumbered A Zones................................................................9-19 Premiums...............................................................................................9-20 C. The Community Rating System..............................................................9-22 Benefits.............................................................................................9-22 CRS activities.........................................................................................9-23 Public information activities.............................................................9-23 Mapping and regulation activities.....................................................9-24 Flood damage reduction activities....................................................9-24 Flood preparedness activities............................................................9-25 Publications............................................................................................9-25 D. The Coastal Barriers Resources System.................................................9-27 Unit 10: Disaster Operations and Hazard Mitigation A. Disaster Operations.................................................................................10-3 Emergency Operations...........................................................................10-3 Building Condition Survey....................................................................10-4 High water marks..............................................................................10-4 Work maps........................................................................................10-4 Conduct.............................................................................................10-5 Notice to owners...............................................................................10-5 Permit Requirements..............................................................................10-7 Permit required..................................................................................10-7 Clean up and emergency repairs.......................................................10-7 Enforcement...........................................................................................10-7 Initial inspection................................................................................10-8 Posting...............................................................................................10-8 Follow up........................................................................................10-11 Flooded buildings............................................................................10-11 Contractor quality control...............................................................10-12 Administration.....................................................................................10-12 Permit forms....................................................................................10-12 Public information...........................................................................10-13 Technical assistance........................................................................10-13 Staff assistance................................................................................10-14 B. Hazard Mitigation.................................................................................10-15 Mitigation Measures............................................................................10-15 Prevention.......................................................................................10-16 Property protection..........................................................................10-16 Natural resource protection.............................................................10-16 Emergency services.........................................................................10-17 Structural projects...........................................................................10-17 Public information...........................................................................10-18 Mitigation Planning.............................................................................10-18 Benefits of planning........................................................................10-18 The planning process......................................................................10-19 Disaster Mitigation Act of 2000 Planning Requirements....................10-20 Multi-Objective Management..............................................................10-20 M-O-M guidelines...........................................................................10-21 Benefits...........................................................................................10-22 C. Mitigation Assistance Programs............................................................10-24 Technical Assistance............................................................................10-24 Property Owners..................................................................................10-25 Flood Mitigation Assistance Program.................................................10-25 Planning grants................................................................................10-26 Project grants...................................................................................10-27 Pre-Disaster Mitigation Program.........................................................10-28 Disaster Assistance..............................................................................10-28 Technical assistance........................................................................10-28 Financial assistance.........................................................................10-29 Appendix A: FEMA Regional Offices........................................................A-1 Appendix B: State Contacts..........................................................................B-1 Appendix C: References...............................................................................C-1 Appendix D: Glossary..................................................................................D-1 Appendix E: NFIP Regulations....................................................................E-1 Appendix F: FEMA Forms...........................................................................F-1 Appendix G: EMI Courses...........................................................................G-1 Appendix H: Learning Checks and Exercises.............................................H-1