(A) A development permit shall be obtained before construction or development, including placement of manufactured homes, within any special flood hazard area. Each application for a development permit or extension of a development permit shall be made on forms furnished by the Floodplain Administrator.
(B) The Floodplain Administrator may require at a minimum, the applicant to submit:
(1) Engineered plans, in duplicate, drawn to scale, showing the nature and location of the area, regulatory flood elevations, dimensions and contours or key elevations, watercourses, and the locations of existing and proposed structures, fill, storage of materials, and drainage facilities. All elevations or vertical distances must reference an established datum or base elevation;
(2) Description of the extent to which any watercourse will be altered or relocated as a result of the proposed development and cumulative development;
(3) When structures are involved:
(a) Structures shall be designed and constructed so as to offer the minimum obstruction to the flow of flood waters. Foundation systems shall be designed and certified by a registered professional engineer;
(b) Proposed elevation in relation to mean sea level, of the lowest floor (including basement) of all structures, plus elevation of existing grade, in relation to mean sea level, all elevations shall be certified by a registered civil engineer or a registered land surveyor, registered in the State of Arizona;
(c) Proposed elevation in relation to mean sea level to which each non-residential structure shall be flood-proofed;
(d) Certification by a registered professional engineer or architect that the flood-proofing methods for each non-residential structure meet the flood-proofing criteria in § 152.045(C)(3);
(e) Base flood elevation data for subdivision proposals or other development greater than 50 lots or five acres, whichever is the lesser; and
(f) Description of the extent to which any watercourse will be altered or relocated as a result of proposed development.
(4) More extensive submissions if the proposed development is in a designated floodway or in an area that will act as a floodway during a major flood. Developers in these areas, including gravel and sand excavators, shall submit a plan, a time schedule and a report, all signed by a registered civil engineer. The plan, in duplicate, shall be to a scale of one inch equals 100 feet or greater and shall contain contours with a contour interval of two feet or less.
(C) In the case of gravel and sand excavation, the plan shall indicate the locations and depths of excavations, and the locations of trees and banks and how they will be protected or disposed of, and the time schedule shall indicate approximate volumes to be removed on a quarterly basis up to the end of the operation. The report shall deal with the hydrology, hydraulics and sediment aspects of the development, shall demonstrate that no increase in flood levels during the occurrence of the base flood discharge would occur, shall address concerns over loss of life and property damage, shall treat bank erosion and channel aggradation and degradation, and shall contain water surface profile studies and quantitative or semi-quantitative sediment analyses if required to support the conclusions in the report. A registered civil engineer may make a written request to waive certain items, accompanied by explanations. It is stressed that encroachments in floodways are prohibited, as per § 152.050, and that only in rare cases would exceptions be made.
(Ord. 2019-863, passed 1-8-2019)