Multi-Hazard Mitigation Plan: 19. Mitigation Strategy

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Chapter 19:Mitigation Strategy public. These warning and evacuation operations were most recently publicly tested in 1994 by evacuation for a tsunami which turned out to be non-hazardous. • Public Education. The Disaster Preparedness pages of the telephone directory (provided by Civil Defense) are a basis for education of the public and are usually referred to in other safety material. The State provides a recent tsunami safety video which is shown on television and to various groups; it emphasizes checking the phone book pages to see if you are in an evacuation zone. The Pacific Tsunami Museum in Hilo has a primary mission of public education and awareness and safety and has exhibits on warning and response. The monthly siren test includes an EAS message about public response, on all radio stations. • Structural Integrity. The Flood Insurance Rate Maps (FIRM), which used much of the same data as the inundation/evacuation work, are an aid to minimize risk to structures, along with County planning and building restrictions. The FIRM is considered more reliable for tsunamis than for stream flooding,but is known to also have some questionable areas in this regard. The County permitting process considers both public and structural safety in its regulations. The FEMA flood insurance program is a significant force in limiting home construction and design in probable inundation areas. The mortgage lenders are especially careful in this regard. Thus, in recent years, exposure has become more limited in scope. A detailed engineering publication which deals specifically with structural design to resist tsunamis is available to building code, permitting, and architecture users, is available.14 The report was prepared for FEMA and coordinated with Tsunami Technical Advisory Committee and the University of Hawaii. Much of it applies to all exposed structures, not just residential. A recent, less technical report describes procedures to improve the tsunami resilience of communities.115 It is primarily oriented toward the mainland coast although the California zonation example they describe was performed here. • Recovery of Critical Facilities. Recovery may be the most difficult to plan because of the unpredictability of the nature and extent of the damage. For example, major damage to harbor facilities, interrupting the fuel supply, can result in loss of part of the electrical supply and thus of water and sewage. Other islands may (or may not) compete for recovery support, compounding the problem for this island. The Department of Transportation has recovery plans which are supplemented with current GIS layers in other portions of this report. 19.2.4 Rainfall Flooding and High Waves Of the major natural hazards, flooding occurs most frequently. Mitigation measures include preventive land use measures, warning systems and public education, flood control structural projects,repetitive loss buyout programs, and natural resource protection programs. • Land use measures. Preventive land use measures rely on accurate flood zone identification. The existing Flood Insurance Rate Maps (FIRM) does not cover all flood-prone areas and require updating for areas that are covered. Recognizing the cost to modernize the FIRM island wide, mitigation actions will prioritize the modernization effort. When updating, 114"Design and Construction Standards for Residential Construction in Tsunami-prone Areas in Hawaii",Dames and Moore,Honolulu and Washington,D.C.,January 1980. 115 "Designing for Tsunamis",National Tsunami Hazard Mitigation Steering Committee,NOAA,March 1991. 19-6 Hawaii County Multi-Hazard Mitigation Plan