improvement plans are not provided, the Floodplain Administrator may require additional information and engineering plans prior to issuing a floodplain use permit. All final plats, tentative plats and development plans shall show proposed grading and drainage improvements. Grading and drainage plans shall demonstrate: The methods for proofing and/or drainage control for the development, including sufficient lot grading information to demonstrate adequate finished pad elevations and/or drainage slopes to protect building foundations; That improvements are compatible with the existing upstream and downstream drainage conditions and that any proposed grading and/or change will not have an adverse impact on surrounding properties; The methods of erosion and sediment control; The methods of mitigating increased urban peak and volumetric food water runoff or discharge on downstream properties created as a result of the development. Floodplain and Floodway Boundaries - Drainage All final plats and development plans shall indicate the limits of the regulatory floodplains, erosion hazard boundaries, and the limits of the federally established regulatory floodplains and floodway (if applicable), and be delineated in a surveyable manner and sealed by an Arizona Registered Land Surveyor. Where subdivision improvements modify or remove the SFHA that is designated on the federal FIRM, a hydraulic analysis of the impact and the engineering plans for the modifications must be approved by the District and a CLOMR submitted and approved by FEMA prior to the recording of the final plat. modification of a federally defined floodway is proposed, approval of a CLOMR by FEMA amending the floodway boundary is required prior to the recording of the final plat. Prior to the release of assurances for subdivisions or certificate of occupancy for development plans, the LOMR must be approved by the Flood Control District and FEMA. Street Elevation Requirements Streets required for paved permanent access shall be designed and constructed so that the flow depths over them do not exceed 1 foot in depth during the base flood.
improvement plans are not provided, the Floodplain Administrator may require additional information and engineering plans prior to issuing a floodplain use permit. All final plats, tentative plats and development plans shall show proposed grading and drainage improvements. Grading and drainage plans shall demonstrate: The methods for proofing and/or drainage control for the development, including sufficient lot grading information to demonstrate adequate finished pad elevations and/or drainage slopes to protect building foundations; That improvements are compatible with the existing upstream and downstream drainage conditions and that any proposed grading and/or change will not have an adverse impact on surrounding properties; The methods of erosion and sediment control; The methods of mitigating increased urban peak and volumetric food water runoff or discharge on downstream properties created as a result of the development. Floodplain and Floodway Boundaries - Drainage All final plats and development plans shall indicate the limits of the regulatory floodplains, erosion hazard boundaries, and the limits of the federally established regulatory floodplains and floodway (if applicable), and be delineated in a surveyable manner and sealed by an Arizona Registered Land Surveyor. Where subdivision improvements modify or remove the SFHA that is designated on the federal FIRM, a hydraulic analysis of the impact and the engineering plans for the modifications must be approved by the District and a CLOMR submitted and approved by FEMA prior to the recording of the final plat. modification of a federally defined floodway is proposed, approval of a CLOMR by FEMA amending the floodway boundary is required prior to the recording of the final plat. Prior to the release of assurances for subdivisions or certificate of occupancy for development plans, the LOMR must be approved by the Flood Control District and FEMA. Street Elevation Requirements Streets required for paved permanent access shall be designed and constructed so that the flow depths over them do not exceed 1 foot in depth during the base flood.
1133_FLOODPLAIN_Management_Ordinance_2013.docx