Mitigation is best employed at the time a coastal building is planned and designed, because that affords an opportunity to maximize mitigation benefits while minimizing mitigation costs.
For new construction, mitigation efforts can best be directed at the following:
If a property owner has an existing building and wants to make it more hazard resistant, the building can be "retrofitted." While it is preferable to design and build in a hazard-resistant method originally, there are steps an owner of an existing building can take, particularly with respect to wind and wind-driven rain resistance. Improving the flood resistance of an existing building often involves elevating the building on a new foundation.
Other helpful tips include:
- Consult the building code official and floodplain administrator, as well as others with knowledge of local construction requirements and hazards. Discuss design options with a knowledgeable insurance agent-before the design is finalized-in order to maximize any insurance discounts that may be available.
- Understand the risk of building along the coast and select a parcel that is not on the shoreline and preferably is not in an SFHA. If a property has not yet been acquired, select a parcel that has a stable shoreline, or if the shoreline is erosional, select a parcel with a low erosion rate; select a parcel that is large enough to accommodate construction without encroaching on sand dunes or a bluff edge; a generous setback from dunes, bluffs and shorelines is recommended.
- If a property has been acquired, site the building on the portion of the parcel away from dunes, bluffs, eroding shorelines and sensitive site features. If the land is on the shoreline, consider other uses, including donating/selling the land to a land trust to keep as open space. Investigating whether there is transfer/purchase of development rights program in your community is another option to consider.
- Elevate the lowest floor of the building above the Base (1-%-annual-chance) Flood Elevation (BFE). Adding freeboard (a factor of safety usually expressed in feet above a flood level for the purposes of floodplain management) will reduce the likelihood and severity of flood damage, and will yield substantial flood insurance premium discounts.
- Where appropriate, use VE Zone foundations in AE Zones. Use a deep and open foundation (piles or columns) that can resist erosion and allow flood water and waves to pass through unobstructed. This may be appropriate in areas designated as LiMWAs on the FIRM and other areas known to the community to be at high risk.
- Consider maintaining natural buffers along shorelines (i.e., keep vegetation in its natural state).
- Design all aspects of the elevated building to resist wind and wind-driven rain. Protect all windows, doors, and openings by using shutters or by constructing using impact-resistant glazing. Building codes have minimum design and construction requirements, but these do not necessarily translate into a wind-resistant and watertight building. Post-storm investigations often reveal deficiencies in buildings subject to less than design wind speeds.