17-3-2 Basis for Establishing the Regulatory Floodplain Areas.
The special flood hazard areas identified by the Federal Emergency Management Agency (FEMA) in a scientific and engineering report entitled “The Flood Insurance Study (FIS) for Pima County, Arizona and Incorporated Areas,” revised September 28, 2012, with accompanying Flood Insurance Rate Maps (FIRMs) dated June 16, 2011, and all subsequent amendments and/or revisions, are hereby adopted by reference and declared to be a part of this chapter. This Flood Insurance Study (FIS) and attendant mapping are the minimum area of applicability of this chapter and may be supplemented by studies for other areas which allow implementation of this chapter and which are recommended to the Floodplain Board by the Floodplain Administrator. The Floodplain Board, within the incorporated limits of the Town of Oro Valley, shall require developers of land to delineate, within areas where development is ongoing or imminent, floodplains consistent with the criteria developed by FEMA, the Arizona Director of Water Resources, and the Town Engineer, pursuant to the Town’s adopted drainage criteria manual. The Flood Insurance Study and FIRMs are on file at the Town of Oro Valley Public Works Department.
A. Regulatory floodplains shall be subject to requirements in Section 17-5-8 (Floodway Fringe Area Requirements).
B. Elevation and Boundary Refinements.
1. The determination of elevations (water surface, lowest finished floor, and adjacent land) and regulatory floodway and regulatory floodplain boundaries is an engineering function with calculations and decisions made in accordance with the concepts and policies set forth in this chapter. The best technical data available shall be used for such calculations and decisions. Initial determinations shall be based on floodplain information reports of the Pima County Flood Control District, U.S. Corps of Engineers, U.S. Bureau of Reclamation, U.S. Geological Survey, and/or other general data that are pertinent for the conditions of the streams or the watercourses at the time the data are obtained.
2. Additional and more detailed technical analysis will, from time to time, become available through private or governmental studies and activities. This data will permit refinements in the elevations and boundaries of the regulatory floodway and regulatory floodplains in the respective reaches of the streams or watercourses.
3. Whenever such additional data become available and it seems desirable to make refinements, i.e., letter of map amendments (LOMAs) or letter of map revisions (LOMRs), such refinements or revisions may be made at the request of the property owners or developers or by the Town Engineer. The necessary engineering calculations shall be made for the property owner or developer by an Arizona registered professional engineer (at the owner’s/developer’s expense) in conformance with requirements of this chapter, the FEMA, and the Arizona Department of Water Resources. These findings will need approval of the Town Engineer. Following the Town’s approval of these refinements to regulatory floodplain areas identified on FIRMs, the property owner shall have calculations and forms forwarded to FEMA for review and approval.
4. The Town Engineer or their duly designated representative shall have the authority and responsibility to revise and refine elevations and boundaries of regulatory floodways and regulatory floodplains whenever such revisions and refinements are for the purpose and in accordance with the conditions set forth in Sections 17-4-3(B)(1)(d), 17-5-8(B)(3), (4), and (5).
a. The Flood Insurance Rate Map for Pima County and incorporated areas shall be revised to show the refined area boundaries and/or elevations.
b. The Town Engineer shall notify the owner of each property for which area boundaries and/or elevations have been revised or refined, as well as those owners of adjoining property immediately upstream and downstream, by first class mail following a duly noticed public hearing on the property involved.
c. An appeal to the Floodplain Board may be taken by any person aggrieved, in accordance with Article 17-6. ((O)21-06, 11/17/2021; (O)17-04, 04/05/2017; (O)05-35, 10/05/2005)