47.5 MB - The Whole Building Design Guide

2.3 REQUIREMENTS AND BESTPRACTICES IN SPECIAL HAZARDAREAS2.3.1 RISK REDUCTION IN “A ZONES”Flood hazard areas designated as A Zones on FIRMs are areaswhere significant wave action is not expected (see Section2.1.1.2). A Zones are found along riverine bodies of water(rivers, streams, creeks, etc.), landward of V Zones, and on someopen coastlines that do not have mapped V Zones. When constructinga critical facility on a site affected by an A Zone flood hazard, sitedesign is influenced by several constraints, such as the presence offlood hazard areas, wetlands, poor soils, steep slopes, sensitive habitats,mature tree stands, and the environmental requirements set bythe various regulatory authorities and the agency that approves developmentplans.Four aspects of the design of flood-resistant buildings and sites aredescribed in this section: site modifications, elevation considerations,flood-resistant materials, and floodproofing considerations.Section 2.3.5 addresses related facilities, including access roads,utility installations, water and wastewater systems, storage tanks,and accessory structures.2.3.1.1 Site ModificationsWhen sites being considered for critical facilities are affected byflood hazards, planners and designers may want to evaluate thefeasibility of certain site modifications in order to provide an in-MAKING CRITICAL FACILITIES SAFE FROM Flooding2-55