(a)   It is the purpose of this chapter for the City of Ionia to participate in the National Flood Insurance Program and comply with all applicable statutory and regulatory requirements for the purposes of significantly reducing hazards to persons, property damage and public expenditures due to flooding of the Grand River, and to provide for the availability of flood insurance and Federal funds or loans.

   (b)   This District is an overlay district and is intended to supplement the regulations of any underlying zone.

   For the purpose of this chapter, the following definitions shall apply:

   (a)   Base Flood means the flood having a one percent chance of being equaled or exceeded in any given year.

   (b)   Flood or Flooding means a general and temporary condition of partial or complete inundation of normally dry land areas from:

      (1)   The overflow of inland or tidal waters;

      (2)   The unusual and rapid accumulation of runoff of surface waters from any source.

   (c)   Flood Hazard Area means land which, on the basis of available floodplain information, is subject to a one percent or greater chance of flooding in any given year.

   (d)   Flood Hazard Boundary Map (FHBM) means an official map of a community, issued by the Federal Insurance Administration, where the boundaries of the areas of special flood hazards have been designated as Zone A.

   (e)   Flood Insurance Rate Map (FIRM) means an official map of the community on which the Federal Insurance Administration has delineated both the areas of special flood hazards and the risk premium zones applicable to the community.

   (f)   Flood Insurance Study is the official report provided by the Federal Insurance Administration. The report contains flood profiles and, the water surface elevation of the base flood and may include a Flood Boundary - Floodway Map.

   (g)   Floodplain means any land area susceptible to being inundated by water from any source (see definition of flood).

   (h)   Floodway means the channel of a river or other watercourse and the adjacent land areas which must be reserved in order to discharge the base flood.

   (i)   Regulatory Flood Datum (RFD) means the 100-year floodplain contour line synonymous with base flood elevation.

   (j)   Structure means a walled and roofed building that is principally above ground, a gas or liquid storage facility, or a mobile home.

   (k)   Substantial Improvement means any repair, reconstruction, or improvement of a structure, the cost of which equals or exceeds 50% of the market value of the structure either: (1) before the improvement or repair is started; or (2) if the structure has been damaged and is being restored, before the damage occurred. For the purposes of this definition, “substantial improvement” is considered to occur when the first alteration of any wall, ceiling, floor, or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure. The term does not, however, include either: (1) any project for improvement of a structure to comply with existing State or local health, sanitary or safety code specifications which are solely necessary to assure safe living conditions; or (2) any alteration of a structure listed on the National Register of Historic Places or a State Inventory of Historic Places.

   (a)   The requirements of this chapter are in addition to and shall supplement those imposed on the same lands by any underlying zoning provisions of this Zoning Code or other ordinances of the City of Ionia. These regulations supersede all conflicting regulations of the underlying zoning districts to the extent of any such conflict.