1136.04 USE AND DEVELOPMENT STANDARDS FOR FLOOD HAZARD REDUCTION.
(a) Use Regulations.
(1) Permitted uses. All uses not otherwise prohibited in this section or any other applicable land use regulation adopted by the City of Whitehall are allowed provided they meet the provisions of this chapter.
(2) Prohibited uses.
A. Private water supply systems in all special flood hazard areas identified by FEMA, permitted under Chapter 3701 of the Ohio Revised Code.
B. Infectious waste treatment facilities in all special flood hazard areas, permitted under Chapter 3734 of the Ohio Revised Code.
C. Storage or processing of materials that are hazardous, flammable, or explosive in the identified special flood hazard area.
D. Storage of material or equipment that, in time of flooding, could become buoyant and pose an obstruction to flow in identified floodway area.
(b) Water and Wastewater Systems. The following standards apply to all water supply, sanitary sewerage and waste disposal systems not otherwise regulated by the Ohio Revised Code:
(1) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems;
(2) New and replacement sanitary sewerage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharge from the systems into flood waters; and,
(3) On-site waste disposal systems shall be located to avoid impairment to or contamination from them during flooding.
(c) Subdivisions and Large Developments.
(1) All subdivision proposals shall be consistent with the need to minimize flood damage and are subject to all applicable standards in this chapter.
(2) All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage.
(3) All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage.
(4) In all areas of special flood hazard where base flood elevation data are not available, the applicant shall provide a hydrologic and hydraulic engineering analysis that generates base flood elevations for all subdivision proposals and other proposed developments containing at least fifty (50) lots or five (5) acres, whichever is less.
(d) Residential Structures.
(1) New construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. Where a structure, including its foundation members, is elevated on fill to or above the flood protection elevation, the requirements for anchoring (Section 1136.04
(d)(1)) and construction materials resistant to flood damage (Section 1136.04
(d)(2)) are satisfied.
(2) New construction and substantial improvements shall be constructed with methods and materials resistant to flood damage.
(3) New construction and substantial improvements shall be constructed with electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities that are designed and/or elevated so as to prevent water from entering or accumulating within the components during conditions of flooding.
(4) New construction and substantial improvement of any residential structure, including manufactured homes, shall have the lowest floor, including basement, elevated to or above the flood protection elevation. In Zone A areas with no elevations specified, the structure shall have the lowest floor, including basement, elevated at least two feet above the highest adjacent natural grade. Support structures and other foundation members shall be certified by a registered professional engineer or architect as designated in accordance with ASCE 24, Flood Resistant Design and Construction.
(5) New construction and substantial improvements, including manufactured homes, that do not have basements and that are elevated to the flood protection elevation using pilings, columns, posts, or solid foundation perimeter walls with openings sufficient to allow unimpeded movement of flood waters may have an enclosure below the lowest floor provided the enclosure meets the standards listed below.
A. Be used only for the parking of vehicles, building access or storage; and
B. Be designed and certified by a registered professional engineer or architect to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters; or
C. Have a minimum of two (2) openings on different walls having a total net area not less than one (1) square inch for every square foot of enclosed area, and the bottom of all such openings being no higher than one (1) foot above grade. The openings may be equipped with screens, louvers, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
(6) Manufactured homes shall be affixed to a permanent foundation and anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors.
(7) Repair or rehabilitation of historic structures upon a determination that the proposed repair or rehabilitation will not preclude the structure's continued designation as a historic structure and is the minimum necessary to preserve the historic character and design of the structure, shall be exempt from the development standards of Section 1136.04(
d).
(e) Nonresidential Structures.
(1) New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall meet the requirements of Section 1136.04
(d)(1)-(3) and (5)-(7).
(2) New construction and substantial improvement of any commercial, industrial or other non-residential structure shall either have the lowest floor, including basement, elevated to or above the level of the flood protection elevation; or, together with attendant utility and sanitary facilities, shall meet all of the following standards:
A. Be dry floodproofed so that the structure is watertight with walls substantially impermeable to the passage of water to the level of the flood protection elevation;
B. Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and,
C. Be certified by a registered professional engineer or architect, through the use of a Federal Emergency Management Agency Floodproofing Certificate, that the design and methods of construction are in accordance with Section 1136.04
(e)(2)A. and B.
(3) In Zone A areas with no elevations specified, the structure shall have the lowest floor, including basement, elevated at least two (2) feet above the highest adjacent natural grade, or be dry floodproofed to that elevation.
(f) Accessory Structures. Relief to the elevation or dry floodproofing standards may be granted for accessory structures containing no more than 600 square feet. Such structures must meet the standards listed below.
(1) They shall not be used for human habitation.
(2) They shall be constructed of flood resistant materials.
(3) They shall be constructed and placed on the lot to offer the minimum resistance to the flow of floodwaters.
(4) They shall be firmly anchored to prevent flotation;
(5) Service facilities such as electrical and heating equipment shall be elevated or floodproofed to or above the level of the flood protection elevation.
(g) Recreational Vehicles. Recreational vehicles must meet at least one of the standards listed below.
(1) They shall not be located on sites in special flood hazard areas for more than 180 days, or
(2) They must be fully licensed and ready for highway use, or
(h) Above Ground Gas or Liquid Storage Tanks. All above ground gas or liquid storage tanks shall be anchored to prevent flotation or lateral movement resulting from hydrodynamic and hydrostatic loads.
(i) Assurance of Flood Carrying Capacity. Pursuant to the purpose and methods of reducing flood damage stated in this chapter, the additional standards listed below are adopted to assure that the reduction of the flood carrying capacity of watercourses is minimized:
(1) Development in floodways.
A. In floodway areas, development shall cause no increase in flood levels during the occurrence of the base flood discharge. Prior to issuance of a floodplain development permit, the applicant must submit a hydrologic and hydraulic analysis, conducted by a registered professional engineer, demonstrating that the proposed development would not result in any increase in the base flood elevation; or
B. Development in floodway areas causing increases in the base flood elevation may be permitted provided the applicant obtains prior approval by the Federal Emergency Management Agency in the form of a Conditional Letter of Map Revision.
(2) Development in riverine areas with base flood elevations but no floodways.
A. Prior to issuance of a floodplain development permit, the applicant must submit a hydrologic and hydraulic analysis, conducted by a registered professional engineer, demonstrating that the cumulative effect of any proposed development, when combined with all other existing and anticipated development, shall not increase the base flood elevation more than 0.5 foot at any point.
B. Development causing more than 0.5 foot increase in the base flood elevation may be permitted provided the applicant obtains prior approval by the Federal Emergency Management Agency in the form of a Conditional Letter of Map Revision.
(3) Alterations of a watercourse. For the purpose of this chapter, a watercourse is altered when any change occurs within the channel banks including changes to size or dimension of the channel, or relocation of the channel. For all proposed developments that alter a watercourse, the standards listed below apply.
A. The flood carrying capacity of the altered or relocated portion of the watercourse shall not be diminished. Prior to the issuance of a floodplain development permit, the applicant must submit a description of the extent to which any watercourse will be altered or relocated as a result of the proposed development, and engineering documentation demonstrating that the flood carrying capacity of the watercourse will not be diminished.
B. Adjacent communities impacted by the watercourse alteration, and the Ohio Department of Natural Resources, Division of Water, must be notified prior to any alteration or relocation of a watercourse. Evidence of such notification must be submitted to the Federal Emergency Management Agency.
C. The applicant shall be responsible for providing the necessary maintenance for the altered or relocated portion of said watercourse so that the flood carrying capacity will not be diminished. The Floodplain Administrator may require the permit holder to enter into an agreement with the City of Whitehall specifying the maintenance responsibilities as well as providing an easement suitable for the City to access the channel and provide maintenance if the agreement obligation is not met by the permit holder. If an agreement and/or easement are required, it shall be made a condition of the floodplain development permit.
D. The applicant shall meet the requirements to submit technical data in Section 1136.03
(j)(1)A.(iii) when an alteration of a watercourse results in the relocation or elimination of the special flood hazard area, including the placement of culverts.
(j) Storage of Material. Storage of material or equipment not otherwise prohibited in Section 1136.04
(a)(2) shall be firmly anchored to prevent flotation.
(Ord. 081-2023. Passed 10-3-23.)