Floodplain Management in American Samoa
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2010 FLOODPLAIN MANAGEMENT IN AMERICAN SAMOA AN SAMOA RIC º 1 E 7 A M P A R F I O L L 1 9 A 0 E 0 S S A A Quick M U OA AT MUAMUA LE GuideAmerican Samoa Department of Commerce American Samoa Coastal Management Program 684-633-5155 Pago Pago, American Samoa Table of Contents 1..... About this Guide 30... Use the Stream Flood Profile to Determine BFEs 2..... Useful Resources 31... Approximate Zone A 3..... Selected Definitions 32... Approximate Zone A Procedures 10... American Samoa Disaster Declarations 33... Nature Doesn’t Read Maps! 11 ... National Flood Insurance Program 34... Letters of Map Change 12... Effects of Non-Participation in the NFIP 35... Some Activities Requiring Floodplain Development 13... NFIP Community Rating System Permits 14... Why Do We Regulate the Floodplain? 36... Some Key Steps in Floodplain Development Permit 15... Natural and Beneficial Floodplain Functions Review 16... Community Responsibilities 37... American Samoa Permitting Process 17... Annual Chance Floods 39... Complete the Permit Application 18... Flood Zones in American Samoa 40... Think Carefully Before You Seek a Variance 19... Looking for Floodplain Information? 41... Floodplain Fill Can Make Things Worse 20... FEMA Online Flood Map Tools 42... Floodplain Fill 21... The Digital FIRM 43... What is an Elevation Certificate and How is it Used? 22... What is Meant by Pre-FIRM and Post-FIRM? 44... Completing the Elevation Certificate 23... Understanding the Coastal Floodplain 45... Is Your Building Site Higher than the BFE? 24... The Coastal DFIRM 46... The Lowest Floor 25... Use the Transect Data Table to Determine Coastal 47... The Lowest Horizontal Structural Member BFEs 48... Typical Elevation Methods for Coastal Construction 27... Introduction to the Riverine Watershed 49... Coastal Structures Must Meet Wind and Water Forces 28... Understanding the Riverine Floodplain 50... Breakaway Walls 29... The Riverine DFIRM 51... Elevated Floodplain Structure (A-Zones) Table of Contents (continued) 52... Elevating an Existing Structure (A Zones) 65... Substantial Improvement A Zone: Renovation Only 53... Enclosures Below the Lowest Floor (A Zones) 66... Substantial Improvement A Zone: Lateral Addition Only 54... Crawlspace Details 67... Substantial Improvement A Zone: Addition Plus Other 55... Utility Service / Fuel Tanks Work 56... Berms/Floodwalls Can Protect Pre-FIRM Structures 68... Substantial Improvement A Zone: Vertical Addition 57... Accessory Structures 69... Non-Substantial Improvements 58... Private Water Crossings 70... What About After Damage? 59... Septic Tanks 71... Substantial Damage Estimator 60... Planning to Improve Your Floodplain Building? 72... Paying for Post Flood Compliance - ICC 61... Substantial Improvement V Zone: Renovation Only 73... Flood Insurance: Property Owner’s Best Protection 62... Substantial Improvement V Zone: Lateral Addition 74... Freeboard: Go Above the BFE (A Zones) Only 75... Freeboard: Go Above the BFE (V Zones) 63... Substantial Improvement V Zone: Lateral Addition 76... Mandatory Purchase Requirement Plus Other Work 77... Floodplain Management Best Practices 64... Substantial Improvement V Zone: Vertical Addition 78... Want to Learn More? About this Guide 2010 FLOODPLAIN MANAGEMENT IN AMERICAN SAMOA This Quick Guide about why and how American Samoa manages AN SAMOA RIC º 1 E 7 A M P A R F I O L L 1 9 A 0 will help you understand more E 0 S floodplains and regulates floodplain development to protect people and property. S A A Quick M U OA AT MUAMUA LE Floodprone communities adopt ordinances GuideAmerican Samoa Department of Commerce that detail the rules and requirements for American Samoa Coastal Management Program 684-633-5155 Pago Pago, America Samoa floodplain development. the Executive Order No. 004-2006, The For more detail on all aspects of floodplain management, please refer toTerritory the Federal of American Emergency SamoaIn caseManagement Floodplain of conflict, Agency (FEMA) National Flood Insurance Program Floodplain ManagementManagement Requirements Regulations, Study Guide and Desk Reference for Local Officials Managerto the American at direct633-5155. Samoaquestionspublication, Coastal and comments Management must be onfollowed. thisProgram Development of the and not this Please Quick Guide (FEMA 480). 1 Quick Guide was taxpayer funded through the Federal Emergency Management Agency. american samoa quick guide Useful Resources Common Acronyms Internet Links ASCMP – American Samoa Coastal Management Program American Samoa Department of Commerce http://www.doc.as ASVD – American Samoa Vertical Datum of 2002 BFE – Base Flood Elevation American Samoa Department of Homeland Security Emergency Management CLOMA – Conditional Letter of Map Amendment http://americansamoa.gov/asdhs/index.htm CLOMR – Conditional Letter of Map Revision American Samoa Department of Public Works CLOMR-F – Conditional Letter of Map Revision based on Fill http://americansamoa.gov/departments/depts/works.htm DFIRM – Digital Flood Insurance Rate Map Family Disaster Planning DOC – Department of Commerce http://www.redcross.org/ DPW – Department of Public Works http://www.fema.gov/areyouready/ EC – Elevation Certificate Repairing Your Flooded Home, ARC and FEMA ERA – Environmental Review Application http://www.fema.gov/library/viewRecord.do?id=1418 FEMA – Federal Emergency Management Agency NFIP Floodplain Management Requirements FIS – Flood Insurance Study A Study Guide and Desk Reference for Local Officials ICC – Increased Cost of Compliance http://www.fema.gov/plan/prevent/floodplain/fm_sg.shtm LOMA – Letter of Map Amendment NFIP Publications http://www.fema.gov/business/nfip/libfacts.shtm LOMR – Letter of Map Revision LOMR-F – Letter of Map Revision based on Fill FEMA Elevation Certificate http://www.fema.gov/business/nfip/forms.shtm NFIP – National Flood Insurance Program PNRS – Permit Notification and Review System NFIP Technical Bulletins http://www.fema.gov/plan/prevent/floodplain/techbul.shtm SFHA – Special Flood Hazard Area 2 american samoa quick guide Selected Definitions American Samoa Vertical Datum of 2002 – The vertical control datum established for surveying in American Samoa landward of 0.0' mean sea level. Area of Special Flood-Related Erosion Hazard – The land within a community which is most likely to be subject to severe flood-related erosion losses. After a detailed evaluation of the special flood-related erosion hazard area in preparation for publication of the DFIRM, Zone E may be further refined. Base Flood – A term used in the FEMA National Flood Insurance Program to indicate the minimum size flood to be used by a community as a basis for its floodplain management regulations; presently required by regulation to be that flood which has a 1-percent annual chance of being equaled or exceeded in any given year. Also known as a 100-year flood or 1-percent annual chance flood. Base Flood Elevation (BFE) – (1) The height in relation to mean sea level (MSL) expected to be reached by the waters of the Base Flood at specific points in the floodplain areas. (2)The elevation for which there is a 1-percent chance in any given year that flood levels will equal or exceed it. (3)The elevation shown on the Digital Flood Insurance Rate Map (DFIRM) for Zones A, AE, V and VE that indicates the water surface elevation resulting from a flood that has a 1-percent or greater chance of being equaled or exceeded in any given year. In A Zones the BFE is generally based on statistical analysis of stream flow records for the watershed and rainfall and runoff characteristics in the general region of the watershed, and application of hydraulic backwater models. In V Zones stillwater flood elevations and wave crests are considered. Breakaway Wall – In V Zones, a wall that is not part of the structural support of the building and is intended through its design and construction to collapse under specific lateral loading forces, without causing damage to 3 american samoa quick guide Selected Definitions (continued) the elevated portion of the building or supporting foundation system. Coastal High Hazard Area – An area of special flood hazard extending along an open coast and any other area subject to high velocity wave action from storms or seismic sources. Community – American Samoa Territory which has the authority to adopt and enforce floodplain management regulations for all the areas within its jurisdiction. Critical Facility – Any governmental or private nonprofit educational, utility, emergency, medical, or custodial care facility, including a facility for the aged or disabled, and any facility providing emergency shelter to the general public. These facilities must be located outside Zones A, AE, V, and VE flood boundaries. If they are located within a Shaded Zone X, its lowest floor and access must be at or above the 0.2-percent annual chance (500-year) flood level. Development – Any man-made change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations or storage of equipment or materials. Flood – (a) A general and temporary condition of partial or complete inundation of normally dry land areas from: (1) The overflow of inland or tidal waters; (2) The unusual and rapid accumulation or runoff of surface waters from any source; (3) Mudslides (i.e., mudflows) which are proximately caused by flooding as defined in paragraph (a)(2) of this definition and are akin to a river of liquid and flowing