(a) Boundaries: The boundaries of the regulatory floodplains and floodways shall be shown on maps maintained by the city engineer using the best available hydrologic and hydraulic data, such as the flood hazard maps (FHM) and flood insurance rate maps (FIRM) provided by the FEMA. The approximate boundaries of the regulatory floodplains shall also be shown on the city's building zone maps, which serve as the city's flood hazard maps.
For those watercourses where regulatory floodplains are not delineated on the maps maintained by the city engineer, the regulatory floodplains shall be determined by engineering studies. An engineering study shall mean the requirements of these regulations and shall include hydrologic and hydraulic analyses prepared by a state registered professional civil engineer and approved by the city engineer.
(b) Elevations: Where elevations of the base flood have been determined for the regulatory floodplain and floodway delineated on maps maintained by the city engineer (such as the elevations shown on the FEMA flood insurance rate maps, however, FIS profiles shall be used to determine BFE when available), those elevations are hereby made a part of these regulations.
For those watercourses which are delineated on the FIRM as unnumbered A zones or where the base flood elevations have not been previously determined, the base flood elevations shall be determined by an engineering study. The study shall meet the requirements of these regulations and shall include hydrologic and hydraulic analyses prepared by a state-registered professional civil engineer and approved by the city engineer. The study shall further demonstrate that the determination of the base flood elevation and study methodology comply with any applicable criteria established by ADWR and FEMA.
(c) Interpretation of boundaries: Where uncertainty exists, the boundary of any regulatory floodplain or floodway shall be determined by the city engineer. The base flood elevation for the point in question shall be the governing factor in locating the floodplain area boundary on the land. A person contesting a boundary location shall be given a reasonable opportunity to substantiate an alternative location based on technical evidence.
(Ord. No. 7407, § 5, 6-25-90; Ord. No. 10311, § 1, 8-8-06; Ord. No. 11396, § 1, 8-9-16)