Loading...
(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)
(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)
(a) As specified in A.R.S. sections 48-3609 and 48-3613, these regulations shall not:
(1) Affect or apply to facilities constructed or installed pursuant to a certificate of environmental compatibility issued under the authority of A.R.S. title 40, chapter 2, article 6.2.
(2) Affect existing legal uses of property or the right to continuation of such legal use. However, if a nonconforming use of land, building, or structure is discontinued for twelve (12) months or destroyed to the extent of fifty (50) percent of its value, as determined by a competent appraiser, any further use shall comply with this article and these regulations.
(3) Affect reasonable repair or alteration of property for purposes for which the property was legally used on August 3, 1984, or the date on which any regulations affecting such property took effect; except that any alteration, addition or repair to a nonconforming building or structure which would result in increasing its flood damage potential by fifty (50) percent or more shall be either floodproofed (nonresidential structures only) or elevated to or above the regulatory flood elevation. All floodproofing (nonresidential structures only) shall be certified by a state-registered professional civil engineer. A record of such floodproofing shall be maintained on file with the city, which includes a certificate of floor elevation. See section 26-11.2(h).
(4) Affect the construction of streams, waterways, lakes and other auxiliary facilities in conjunction with development of public parks and recreation facilities by a public agency or political subdivision. Any such alteration must maintain the carrying capacity of the watercourse.
(5) Prohibit the construction of bridges, culverts, dikes and other structures necessary for the construction of public highways, roads, and streets intersecting or crossing a watercourse.
(6) Prohibit the construction of storage dams for watering livestock or wildlife, structures on banks of a creek, stream, river, wash, arroyo, or other watercourse to prevent erosion of or damage to adjoining land or dams for the conservation of floodwaters permitted by A.R.S. title 45, chapter 6, section 45-1201 et seq., and chapter 10, section 45-1701 et seq.
(7) Prohibit construction of tailing dams and waste disposal areas for use in connection with mining and metallurgical operations. This does not exempt those sand and gravel operations which will divert, retard or obstruct the flow of waters in any watercourse from complying with and acquiring authorization from the city engineer pursuant to regulations adopted by the floodplain board under this chapter.
(8) Prohibit the construction and erection of poles, towers, foundations, guy wires, and other facilities related to power transmission as constructed by any utility whether a public service corporation or a political subdivision.
(9) Prohibit any flood control district, county, city, town or other political subdivision to exercise powers granted to it under A.R.S. section 48-3601 et seq.
(b) These exceptions do not preclude any person from liability if that person's actions increase flood hazards to any other person or property. Before any construction authorized by this section may begin, plans for such construction must be submitted to the city engineer for review and comment, and/or issuance of a floodplain use permit. A drainage statement or report also may be required.
(Ord. No. 7407, § 5, 6-25-90; Ord. No. 11396, § 1, 8-9-16)
(a) Improvements to, or Reconstruction of, Existing Nonconforming Development:
(1) Any structure which is substantially improved at a cost equal to or exceeding fifty (50) percent of the full cash value of the structure as shown on the latest assessment rolls of the county assessor either (a) before the improvement or repair is started, or (b) if the structure has been damaged and is being restored, before the damage occurred, shall conform to these regulations. At the time of improving or reconstructing the existing structure or development, floodproofing (nonresidential structures only) may be considered as one of the means of bringing it in compliance with this chapter.
For the purpose of determining the value of any such construction, repair or alteration, the normal retail value of the materials and the reasonable value of labor performed shall be used.
(2) Floodplain administrator or designee shall review all improvements to a structure and track all changes over a cumulative ten (10) year period for compliance.
(3) For the purpose of this chapter, "substantial improvement" is also considered to occur, but is not limited to, 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.
(4) No person shall repair or alter property in any manner so as to avoid the provisions of this section.
(b) Discontinuance of Nonconforming Development: In the event that the use of a nonconforming development is discontinued for a period of twelve (12) consecutive months, any further use thereof shall be in conformity with the provisions of these regulations.
(c) Condominium Conversions: These regulations shall not apply to an existing legally constructed building which is subdivided for the purpose of conversion to condominium ownership as long as "substantial improvement" guidelines stated in subsections (a)1--3 of this section are met.
(Ord. No. 7407, § 5, 6-25-90; Ord. No. 11396, § 1, 8-9-16)
Areas designated as floodways have a high potential for flooding. Land in the floodway should be set aside for the conveyance of floodwaters as a first priority. Floodways are also areas of major groundwater recharge, a characteristic which should be preserved and enhanced where possible. Floodways are areas of land that belong to the watercourse, while floodway fringe areas can be shared by people and the watercourse, provided the arrangement does not result in damage to either the people or the watercourse.
(Ord. No. 7407, § 5, 6-25-90)
Development in the floodway shall:
(1) Conform to adopted city land use plans for the design of public and private development in the floodplain.
(2) Not result in damage to public facilities as a result of erosion or flooding events.
(3) Not generate adverse impacts (including but not limited to erosion) upstream or downstream.
(4) Not unnecessarily alter riparian habitats of watercourses and adjacent bank areas.
(5) Not increase the base flood elevations. Certification by a registered professional civil engineer shall be provided that demonstrates that the encroachment shall not result in any increase in flood levels during the occurrence of the base flood discharge.
(6) Not result in higher floodwater velocities which significantly increase the potential for flood or erosion damage.
(7) Not significantly increase channel or bank erosion.
(8) Not decrease groundwater recharge.
(9) Not contain a waste disposal system wholly or partially.
(10) Not result in the placement of any structure or material that may divert, retard or obstruct the flow of floodwaters.
(11) Not result in creating a danger or hazard to life or property.
(12) Not utilize structures except hydraulic structures and those structures exempted under section 26-4(4)--(8) of this ordinance, which are designed and constructed to protect life or property from dangers or hazards of floodwaters.
(13) Not contribute to debris accumulation upstream and/or downstream.
(14) Not create a water pollution problem in the floodway due to soluble, insoluble, or solid materials, at the time of flooding.
(Ord. No. 7407, § 5, 6-25-90; Ord. No. 11396, § 1, 8-9-16)
No development, storage of materials or equipment, or other uses shall be permitted which, acting alone or in combination with existing or future uses, create a danger or hazard to life or property. Development in the floodway fringe shall:
(1) Conform to adopted city land use plans for the design of public and private development in the floodplain.
(2) Not result in damage to public facilities as a result of erosion or flooding events.
(3) Not generate adverse impacts, including but not limited to erosion, upstream or downstream.
(4) Not unnecessarily alter riparian habitats of watercourse and adjacent bank areas.
(5) Not increase the base flood elevation more than one-tenth of a foot, as measured from the property boundary.
(6) Not result in higher floodwater velocities which significantly increase the potential for flood or erosion damage.
(7) Not significantly increase channel or bank erosion.
(8) Use, where appropriate, native and/or adaptive landscaping to enhance the open space character of the floodway fringe.
(9) Place the lowest (including basement) floor one (1) foot above the base flood elevation. In an AO Zone, residential construction, new or substantial damage repairs or improvements, shall have the lowest floor, including basement, elevated to or above the regulatory flood elevation. Prior to the pouring of the first slab or lowest floor installation and prior to any framing, the applicant shall submit to the city engineer certification by state-registered land surveyor or a state-registered professional civil engineer that the elevation of the lowest floor framework is in compliance with that approved by the city engineer's office in the form prepared by FEMA (Elevation Certificate) for preslab (Building Under Construction) and final (Finished Construction).
(10) Anchor all structures, material or equipment firmly to prevent their flotation.
(11) Place service equipment and mechanical items, including but not limited to water heaters, heating/cooling equipment, ductwork, electrical service panels and/or other facilities, as deemed necessary by the floodplain administrator or designee, at or above the regulatory flood elevation.
(12) ) Be constructed so as to protect placed fill from erosion which could be caused by waters, or otherwise. Such fill shall be permitted only when demonstrated by the owner/developer that it will have some beneficial purpose, as determined by the city engineer, and the amount of proposed fill is not in excess of what is necessary to achieve that purpose. The fill shall be protected from erosion which could be accomplished by placing riprap, vegetative cover, bulk heading, or any other floodplain administrator approved methods. Certification of compaction shall be provided as determined by the floodplain administrator.
(13) Prohibit storage and/or processing of materials that are buoyant, flammable, explosive or that could be injurious to human, animal or plant life at the time of flooding.
(14) Locate on-site sanitary waste disposal systems to avoid impairment to them or contamination from them during flooding.
(15) Locate water supply, water treatment and sewage collection and disposal systems to eliminate or minimize infiltration of floodwaters into these systems and discharge of materials from these systems into floodwaters.
(Ord. No. 7407, § 5, 6-25-90; Ord. No. 10311, § 1, 8-8-06; Ord. No. 11396, § 1, 8-9-16; Ord. No. 11801, § 1, 12-8-20)
Loading...