(a) Whenever additional data becomes available and warrants floodplain elevation or boundary revisions, such revisions may be made by the city engineer at the request of property owners or developers upon submission of the necessary engineering calculations and maps prepared by a state-registered professional civil engineer in conformance with the requirements of this chapter, the ADWR, and FEMA. When BFEs increase or decrease, as soon as practicable but not later than six (6) months after the date the information becomes available, FEMA shall be notified by submitting technical or scientific data in accordance with 44 CFR 65.3. The city shall also notify ADWR. Within one hundred twenty (120) days of completion of flood control protective works that change rate of flow or boundaries of the floodplain, all jurisdictions affected by the project are required to be notified.
(b) Whenever a watercourse is to be altered or relocated:
(1) Require that the flood-carrying capacity of the altered or relocated portion of the watercourse is maintained.
(2) Where appropriate, obtain a permit from the corps of engineers in accordance with section 404 of the Clean Water Act.
(3) A development permit is required to be submitted for base flood elevation data for any subdivision proposal or other development greater than fifty (50) lots or five (5) acres, whichever is the lesser.
(c) The city engineer or his designated representative shall have the authority and responsibility to revise the regulatory floodplain and floodway boundaries and base flood elevations on the flood hazard maps (FHM) for the watercourses that are not included on the FIRM.
(1) The city engineer shall notify, within thirty (30) days after his ruling, the owner of each property for which floodplain boundaries and/or base flood elevations have been revised and those owners of adjoining property immediately upstream and downstream. Such specific notice shall not be required when such revisions have been made following a noticed public hearing on the property involved. In addition, the city engineer shall notify ADWR and FEMA.
(d) BFE's may increase or decrease resulting from physical changes affecting flooding conditions. Within one hundred twenty (120) days after completion of construction of any flood control protective works, the revised regulatory floodplain and/or floodway and the revised base flood elevations, in the areas affected by such work, shall be redefined, and shall be provided to the governing bodies of all jurisdictions affected. As soon as is practicable, but not later than six (6) months after the date such information becomes available, the Floodplain Administrator shall notify FEMA of the changes by submitting technical or scientific data in accordance with Volume 44 Code of Federal Regulations (CFR) Section 65.3. This submission is necessary so that upon confirmation of those physical changes affecting flooding conditions, risk premium rates and floodplain management requirements will be based upon current data.
(e) An appeal may be taken to the floodplain board by any person aggrieved by such revisions in accordance with section 26-12 of this chapter.
(Ord. No. 7407, § 5, 6-25-90; Ord. No. 11396, § 1, 8-9-16)