COM 0176.041 2006-2008 - Laserfiche WebLink

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FLOOD PLAIN MANAGEMENT This report is intended to be used as a technical guide by state and local planning groups to control future flood plain land use appropriate to the degree of flood hazard involved. Flood damages will be reduced by implementation of nonstructural measures such as zoning, land acquisition, and flood insurance or by the installation of structural measures such as floodproofing. The County of Hawaii has recently approved several ordinances concerning Iand use within flood-prone areas. Ordinance No. 77, effective December 31, 1974, established a "Safety Flood Hazard District - SF." The Safety Flood Hazard District - SF was described as: "This subdistrict shall apply to areas designated by the Federal Insurance Administration as being subject to special flood and tsunami hazards and indicated on the zone maps as SF districts." The U.S. Department of Housing and Urban Development (HUD) has designated the island of Hawaii for a future Flood Insurance Study under the Regular Program. The island is participating in HUD's Emergency Program. This permits the owners and occupiers of all walled and roofed buildings and mobile homes to purchase subsidized insurance on their structures and contents. Development in the SF District is regulated by County of Hawaii Ordinance No. 76, effective December 31, 1974, which amended Ordinance No. 501, Building Code Ordinance. Ordinance No. 76 is intended to reduce future flood damages by controlling development within floodprone areas. Concerning construction of residential structures, paragraph 3(d) was added to Section III, paragraph 3, Ordinance No. 501 stating: "(d) All new construction or substantial improvements of residential structures in the SF District shall have the lowest floor, including basement, elevated to or above the level of the 100-year flood," The flood boundary lines shown on the flood hazard maps may be used as the basic data for delineation of "Safety Flood Hazard District - SF" and also as the basis for implementation of appropriate county ordinances pertaining to development within flood plains. Floodways pr; Encroachment on flood plains, including roads, buildings, and artificial fill, reduces the flood-carrying capacity and increases flood heights, thus increasing flood hazazds in areas above and below the encroachment itself. One aspect of flood plain management involves balancing the economic gain from flood plain development against the resulting increase in flood hazard. For purposes of HUD's National Flood Insurance Program, a floodway is used as a tool to assist local communities in this aspect of flood plain management. ~11.