Changes to FEMA Mapping John Grace, CFM Coastal Engineer - FEMA Region 1 - Boston March 14, 2014 – The Soil and Water Conservation Society – Winter Conference

2 Program Overview  Risk MAP Mapping – Flood hazard and risk identification Assessment – HAZUS and other risk assessment tools Planning – Hazard mitigation planning and HMA grants  Risk MAP Vision Deliver quality data Increase public awareness of flood risk Encourage local/regional actions that reduce risk

3 Risk MAP Project Timeline Discovery Meeting Project Kickoff Flood Study Review Resilience Meeting Final CCO Meeting 3-5 Year Process

4 FEMA Mapping

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6 Detailed Study – Coastal Analysis  Stillwater Level (storm surge) + Wave Set-up  Overland Wave Propagation  Wave Runup and Overtopping  Primary Frontal Dune Coastal analysis - includes 4 main components:

7 Detailed Study – Stillwater Level (SWEL) with Gage Data  Return period gage analysis  Linear interpolation between gage points

8 Detailed Study – Wave Setup  Numerically determined at each coastal transect  Determining factors  Average nearshore slope [depth of wave breaking to SWEL]  Deepwater significant wave height  SWEL + Wave Setup = Total Water Level (TWL)  Areas where floodplain is restrictive, wave setup is removed and SWEL is mapped  Constrictions such as low bridges  Narrowing of the floodplain

9 Detailed Study – Overland Wave Propagation

10 LiMWA (Limit of Moderate Wave Action)  Areas subject to wave heights greater than 1.5 feet, but less then 3 feet.  Standard flood insurance requirements apply.  No regulatory requirement. (Rhode Island requires V zone regulations)  Defines the coastal A zone.

11 Runupand Overtopping

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13 Primary Frontal Dune

14 FLOOD RISK PRODUCTS

15 Flood Risk Products  These products are intended to help communities better understand and communicate flood risk  Non - Regulatory  All of these products are GIS based The following flood risk products may be available: Changes Since Last FIRM Flood Risk Assessment Contributing Engineering Factors Wave Height Grids Flood Risk Report

16 Changes Since Last FIRM

17 Annualized flood losses are displayed on the Census Block Data Aimed at depicting general flood loss areas Flood Risk Assessment

18 Contributing Engineering Factors Provide insight into the factors behind the increase or decrease in the flood hazard areas Can prove to be useful for planning and mitigation measures

19 Wave Height Grids Provided for 1% annual chance floods

20 Flood Risk Report

21 WEB LINKS  Preliminary Data  Effective Data (including Future Effective) msc.fema.gov  National Flood Insurance Program  Flood Insurance Reform Act