Allowing these pressures to equalize greatly reduces the likelihood of wall failures and structural damage. In V Zones, enclosure walls must be redesigned, constructed, and certified by a registered professional engineer or architect that exterior walls will break away. You should also contact your community officials for information about your community's floodplain management ordinance. Many states maintain a floodplain management technical assistance capability as well as general mitigation assistance capability. A good point of contact would be your state coordinator for the National Flood Insurance Program or your state hazard mitigation officer.
Some NFIP publications are available online .