5-4-13-2: SUBDIVISION WITHIN FLOODPLAIN:

   A.   Flood Areas:

      1.   For any proposed subdivision that is located within a floodplain, the subdivider shall provide the commission with a development plan of adequate scale and supporting documentation that will show and explain at least the following:

         a.   Location of all planned improvements.

         b.   The location of floodways and base flood elevation cross section lines in the floodway fringe in accordance with sound engineering practices.

         c.   The location of the present water channel.

         d.   Any planned rerouting of waterways.

         e.   All major drainageways.

         f.   Areas of frequent flooding.

         g.   Means of floodproofing buildings.

         h.   Means of insuring loans for improvements within the floodplain.

         i.   Provide permanent elevation bench marks.

      2.   To give additional guidance in approving any proposed subdivisions within a floodplain, the City shall review proposed developments considering that new construction and substantial improvements of residential structures within the floodplain shall have the finish floor elevation of the lowest floor, including basement and crawl space, elevated to a minimum of one foot (1') above the base flood elevation; and, for new construction or substantial improvements of nonresidential structures, the finish floor elevation of the lowest floor, including basement and crawl space, elevated to a minimum of two feet (2') above the base flood elevation, or, together with attendant utility and sanitary facilities, shall be floodproofed to a point two feet (2') above the base flood elevation so that the structure is watertight with walls substantially impermeable to the passage of water.

   B.   Justification For Development: Upon determination that buildings are planned within the floodplain or that alterations of any kind are anticipated within the floodplain area that will alter the flow of water, the subdivider shall demonstrate conclusively that such development will not present a hazard to life or limb, hazard to property, adverse effects on the safety, use or stability of a public way or drainage channel and not have an adverse impact on the natural environment.

   C.   Appropriateness Of Subdivision:

      1.   In determining the appropriateness of subdivision for land located within a floodplain, the commission and City shall consider the objectives of this title, and at least the following:

         a.   The danger to life and property due to the increased flood heights or velocities caused by subdivision fill, roads and intended uses.

         b.   The danger that intended uses may be swept onto other lands or downstream to the injury of others.

         c.   The adequacy of proposed water supply and sanitation systems and the ability of these systems to prevent disease, contamination and unsanitary conditions under flood conditions.

         d.   The susceptibility of the proposed facility and its contents to flood damages and the effect of such damage on the individual owner.

         e.   The importance of the services provided by the proposed facility to the community.

         f.   The requirements of the subdivision for a waterfront location.

         g.   The availability of alternative locations not subject to flooding for the proposed subdivision and land uses.

         h.   The compatibility of the proposed uses with existing development and development anticipated in the foreseeable future.

         i.   The relationship of the proposed subdivision to the comprehensive plan and any floodplain management program for the area.

         j.   The safety of access to the property for emergency vehicles in times of flood.

         k.   The expected heights, velocity, duration, rate of rise and sediment transport of the floodwaters expected at the site.

         l.   The costs of providing governmental services during and after flood conditions including maintenance and repair of public utilities and facilities such as sewer, gas, electrical and water systems, and roads and bridges.

      2.   No subdivision or part thereof shall be approved if levees, fills, structures or other features within the proposed subdivision will individually or collectively significantly increase flood flows, heights or damages. If only part of a proposed subdivision can be safely developed, development shall be limited to that part and the Council shall require development to proceed consistent with the determination.

   D.   Floodproofing Plans: Floodproofing plans must be individually approved by the City upon recommendation from the commission before such uses are constructed. Floodproofing may include, but not be limited to, the following:

      1.   Anchorage to resist flotation and lateral movement.

      2.   Installation of watertight doors, bulkheads and shutters or similar methods of closure.

      3.   Reinforcement of walls to resist water pressure.

      4.   Use of paints, membranes or mortars to reduce seepage of water through walls.

      5.   Addition of mass or weight to structures to resist flotation.

      6.   Installation of pumps to lower water levels in structures.

      7.   Construction of water supply and waste treatment systems so as to prevent the entrance of floodwaters.

      8.   Installation of pumps or comparable facilities for subsurface drainage systems to relieve external foundation wall and basement flood pressures.

      9.   Building design and construction to resist rupture or collapse caused by water pressure or floating debris, including, but not limited to, the provision of engineered flood openings.

      10.   Installation of valves or controls on sanitary and storm drains which permit the drains to be closed to prevent backup of sewage and stormwaters into buildings or structures.

      11.   Location and installation of all electrical equipment, circuits and electrical appliances so that they are protected from inundation by the regulatory flood.

      12.   Location of storage facilities for chemicals, explosives, buoyant materials, flammable liquids or other toxic materials which could be hazardous to public health, safety and welfare at elevations above the height associated with the regulatory protection elevation; or design of such facilities to prevent flotation of storage containers, or damage to storage containers which could result in the escape of toxic materials into floodwaters. (Ord. 568, 12-21-2015; amd. Ord. 609, 7-3-2018)