1. Map risk assessment areas. The objective of the Risk Assessment is to define areas at risk from coastal hazards, distinguishing significant differences in the exposure of the landscape. Data was collected from sources accurate enough to differentiate geographic areas according to the likelihood of flooding, erosion, waves and storm surge. To the extent allowed by source data places where flood water can extend up streams and under culverts and bridges are reflected in mapping. Data sources include but are not limited to:

2. Compile mapping into a summary, classifying geographic areas according to differences in vulnerability. Mapped areas described in Step 1 above were overlaid, combined vulnerabilities were used to discriminate geographic areas into three classes:

a. Extreme Risk Areas: Areas currently at risk of frequent inundation, vulnerable to erosion in the next 40 years, or likely to be inundated in the future due to sea level rise:

i. FEMA V zone.

ii. Areas subject to Shallow Coastal Flooding per NOAA NWS’s advisory threshold.

iii. Areas prone to erosion, natural protective feature areas susceptible to erosion.

iv. Added 3 feet to the MHHW shoreline and extended this elevation inland over the digital elevation model (DEM) to point of intersection with ground surface.

Result: An area depicting the maximum extent of the above areas was compiled. This is the Extreme Risk Area.

b. High Risk Areas: Areas outside the Extreme Risk Area that are currently at infrequent risk of inundation or at future risk from sea level rise:

i. Area bounded by the 1% annual flood risk zone (FEMA V and A zones).

ii. Added 3 feet to NOAA NWS coastal flooding advisory threshold and extended this elevation inland over the DEM to point of intersection with ground surface..

Result: An area depicting the maximum extent of the above areas upland of the boundary of the Extreme Risk Area was compiled. This is the High Risk Area.

c. Moderate Risk Areas: Areas outside the Extreme and High Risk Areas but currently at moderate risk of inundation from infrequent events or at risk in the future from sea level rise.

i. Area bounded by the 0.2% annual risk (500 year) flood zone, where available.

ii. Added 3 feet to the Base Flood Elevation for the current 1% annual risk flood event and extended this elevation inland over the DEM to point of intersection with ground surface.

iii. Area bounded by SLOSH category 3 hurricane inundation zone.

Result: An area depicting the maximum extent of the above areas upland of the boundary of the High Risk Area was compiled. This is the Moderate Risk Area. (7/1/13)