47.5 MB - The Whole Building Design Guide

overview on performance-based design). If located in, or adjacentto, flood hazard areas, it is appropriate to provide protectionfor the building and utility systems to at least the 0.2-percent-annual-chance(500-year) flood level or, at a minimum, 2 to 3 feetabove the DFE. Additional guidance on hazard-resistant shelters isfound in FEMA 361, Design and Construction Guidance for CommunityShelters.Additional measures that may be appropriate for considerationwhen flood-prone critical facilities are used as shelters include thefollowing:m Wastewater service must be functional during conditions of theflooding.m Emergency power service must be provided.m Dry ground access is important, in the event flooding exceedsdesign levels.2.2.2 VULNERABILITY: WHAT FLOODINGCAN DO TO EXISTING CRITICALFACILITIESExisting flood-prone facilities are susceptible to damage, the natureand severity of which is a function of site-specific floodcharacteristics. As described below, damage may include: sitedamage, structural and nonstructural building damage, destructionor impairment of utility service equipment and loss ofcontents.Regardless of the nature and severity of damage, flooded facilitiestypically are not functional while cleanup and repairs areundertaken. The length of closure, and thus the impact on theability of the facility to become operational, depends on the severityof the damage and lingering health hazards. Sometimesrepairs are put on hold pending a decision on whether a facilityshould be rebuilt at the flood-prone site. When damageis substantial, rehabilitation or reconstruction is allowed only ifcompliance with flood-resistant design requirements is achieved(see Section 2.1.3.2).MAKING CRITICAL FACILITIES SAFE FROM Flooding2-41