FEMA On Passive Automatic Flood Protection
FEMA issued Floodproofing Non-Residential Buildings (FEMA P-936 ), a publication to assist local government officials, engineers, architects, and property owners involved in the planning and implementation of floodproofing retrofits. It reflects the latest information on floodproofing retrofits for non-residential structures, and provides guidance on floodproofing existing non-residential buildings in riverine areas subject to shallow flooding and coastal areas not subject to wave action.
This FEMA publication focuses primarily on dry floodproofing, which is making a structure watertight below the expected flood level but provides an overview of other retrofit methods that can be used in conjunction with or independent of dry floodproofing, including: wet floodproofing, floodwalls, levees, protection of utilities and emergency floodproofing measures.
Featured are two FEMA Mitigation Best Practices Stories for Lourdes Hospital in Binghamton, NY and Columbus Regional Hospital in Columbus, IN. Both used passive flood barriers from FloodBreak as part of their flood mitigation. A third FEMA Mitigation story was published for Rosenberg Library in Galveston TX which suffered flood devastation from Hurricane Ike.
INCREASES FLOOD RISK
Installing active dry floodproofing measures, which require human intervention, takes time and requires sufficient warning. Active dry floodproofing measures are therefore not appropriate if the warning time is insufficient. Flash flooding happens quickly and comes unexpectedly. Without sufficient warning time, active measures cannot be implemented putting people and property at risk. See Section 2.5.3 for additional information regarding flood warning time.
Flood Emergency Operations Plans
Dry floodproofing requires emergency operation planning:
- If the proposed floodproofing measure is active (requires human intervention), all roads that provide access to the building should remain passable long enough for the floodproofing measures to be installed and for all personnel to safely evacuate the site.
- When removable shields (i.e. drop in panels, flood panels) are used, flood emergency plans must include: storage location, method of installation, maintenance of equipment, annual installation practice.
- Regular evaluation and update of the flood emergency operations plan must be scheduled to reflect changes in personnel and procedures.
Passive floodproofed buildings result in lower NFIP insurance premiums
Dry floodproofed buildings with active floodproofing measures and requiring human intervention are subject to higher insurance premiums than dry floodproofed buildings with completely passive floodproofing measures that do not require human intervention. (Sec 2.1.1 National Flood Insurance Program)
Other related reference FEMA publications:
- FEMA TB 3 – Non-Residential & Mixed Use Floodproofing Guidelines
- FEMA TB 6 – Below Ground Flood Proofing Guidelines
- USACE EP 1165-2-314 – Flood-Proofing Regulations
- FEMA 551 – Selecting Appropriate Mitigation Measures for Floodprone Buildings
- ASCE 24 – 14 – Flood Resistant Design & Construction (Full report available at http://www.asce.org)