§ 151.073 STANDARDS FOR FLOOD FRINGE CONDITIONAL USES.
   (A)   Alternative elevation methods. Alternative elevation methods other than the use of fill may be utilized to elevate a structure's lowest floor above the regulatory flood protection elevation. These alternative methods may include the use of stilts, pilings, parallel walls, etc., or above-grade, enclosed areas such as crawl spaces or tuck under garages. The base or floor of an enclosed area shall be considered above-grade and not a structure's basement or lowest floor if:
      (1)   The enclosed area is above-grade on at least one side of the structure;
      (2)   Is designed to internally flood and is constructed with flood resistant materials; and
      (3)   Is used solely for parking of vehicles, building access or storage. The above-noted alternative elevation methods are subject to the following additional standards:
         (a)   Design and certification. The structure's design and as-built condition must be certified by a registered professional engineer or architect as being in compliance with the general design standards of the state building code and, specifically, that all electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities must be at or above the regulatory flood protection elevation or be designed to prevent flood water from entering or accumulating within these components during times of flooding.
         (b)   Specific standards for above-grade, enclosed areas. Above-grade, fully enclosed areas such as crawl spaces or tuck under garages must be designed to internally flood and the design plans must stipulate:
            1.   The minimum area of openings in the walls where internal flooding is to be used as a flood proofing technique. When openings are placed in a structure's walls to provide for entry of flood waters to equalize pressures, the bottom of all openings shall be no higher than one-foot above grade. Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of flood waters.
            2.   That the enclosed area will be designed of flood resistant materials in accordance with the FP-3 or FP-4 classifications in the state building code and shall be used solely for building access, parking of vehicles or storage.
   (B)   Residential structures and conditional use permits. No residential structures shall be allowed by conditional use permit or otherwise in the Flood Fringe District except as specifically set forth in §§ 151.120 and 151.121, below.
   (C)   Non-residential structures. All areas of non-residential structures to be placed below the regulatory flood protection elevation shall be flood proofed in accordance with the structurally dry flood proofing classifications in the state building code. Structurally dry flood proofing must meet the FP-1 or FP-2 flood proofing classification in the state building code and this shall require making the structure watertight with the walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy. Structures flood proofed to the FP-3 or FP-4 classification shall not be permitted.
   (D)   Fill and similar material; erosion/sedimentation control plan. When at any one time more than 1,000 cubic yards of fill or other similar material is located on a parcel for such activities as on-site storage, landscaping, sand and gravel operations, landfills, roads, dredge spoil disposal or construction of flood control works, an erosion/sedimentation control plan must be submitted unless the city is enforcing a state approved shoreland management ordinance. In the absence of a state approved shoreland ordinance, the plan must clearly specify methods to be used to stabilize the fill on site for a flood event at a minimum of the 100-year or regional flood event. The plan must be prepared and certified by a registered professional engineer or other qualified individual acceptable to the city. The plan may incorporate alternative procedures for removal of the material from the flood plain if adequate flood warning time exists.
   (E)   Storage of materials and equipment.
      (1)   The storage or processing of materials that are, in time of flooding, flammable, explosive, or potentially injurious to human, animal, or plant life is prohibited.
      (2)   Storage of other materials or equipment may be allowed if readily removable from the area within the time available after a flood warning and in accordance with a plan approved by the city.
   (F)   Section 151.074 to apply. The provisions of § 151.074 shall also apply.
(Ord. 406, passed 11-27-1989)