Rule 4781-12-07.3 | Flood plain management elevations; floodway regulations.
(A) In addition to meeting the other requirements of this chapter, new development of a manufactured home park and development of a new lot in an existing manufactured home park located in a one-hundred-year flood plain shall be filled and graded so that the base support system is elevated to a level that equals the sum of the following:
(1) The one-hundred-year flood elevation;
(2) Up to a maximum of one foot in allowable rise height that is above the one-hundred-year flood elevation and is intended to compensate for an increase in flood heights caused by development in the flood plain. Where a flood study specifies a rise height different from that established by the federal emergency management agency, or a local ordinance specifies a different rise height, that height shall be used; and
(3) One foot in freeboard height, which is an extra margin of safety added to the one-hundred-year flood elevation to account for an increase in flood levels due to waves, debris, hydraulic surge, and other unknown factors.
Where flood plain information is not available, it shall be the responsibility of the person requesting a permit for development to provide the hydrologic and hydraulic data from a registered professional engineer necessary for the division to determine the flood protection elevation and ensure no encroachment upon the regulatory floodway.
(B) Except as provided in paragraph (C) of this rule, before a manufactured home is to be placed or replaced on an existing manufactured home park lot located within a one-hundred-year flood plain, the home shall be elevated so that the chassis is at or above a height equal to the lesser of the following:
(1) Thirty-six inches above the existing elevation of the manufactured home park lot; or
(2) The one-hundred-year flood elevation as specified on the federal emergency management agency's flood insurance rate maps or as determined by a registered professional engineer.
(C) A lot in an existing manufactured home park located within a one-hundred-year flood plain and upon which a manufactured home is substantially damaged as a result of a flood shall be elevated so that the lowest floor of the manufactured home is at or above a height equal to the one-hundred-year flood elevation as specified on the federal emergency management agency's flood insurance rate maps or as determined by a registered professional engineer.
(D) The operator shall upon the request of the division provide written verification from a registered professional engineer or registered surveyor that the elevations required under paragraphs (A), (B), and (C) of this rule have been attained.
(E) No person shall cause development within a regulatory floodway unless it has been demonstrated to the division through hydrologic and hydraulic analysis performed by a registered professional engineer that the proposed development would not result in any increase in the flood levels during the occurrence of a one-hundred-year flood.