Fredonia Flood Retarding Structure: Is it a Dam or Levee?

摘要

A planning study was completed in January 2017 for the Fredonia Flood Retarding Structure (FRS) to recommend a preferred alternative to either breach, rehabilitate or decommission the dam. The preferred alternative selected is to decommission the dam by converting the structure to function as a levee. The conversion of the dam to a levee structure is a unique case that presents the need for an opinion of jurisdictional determination of whether the modified Fredonia FRS is a dam or a levee. Dam safety for the Fredonia FRS is under the jurisdiction of the Arizona Department of Water Resources (ADWR). As part of the decommissioning of the dam, a supportive case must be presented to ADWR that the dam does not meet current ADWR dam jurisdictional definitions and criteria. If ADWR determines that the structure does not meet their jurisdictional definitions, the structure would be determined to be non-jurisdictional. The approach for the final design (currently underway) of the preferred alternative, as a minimum, is to meet Federal Emergency Management Agency (FEMA) levee criteria and requirements for certification and accreditation. This paper discusses the approach and supportive evidence that the "levee" does not meet ADWR jurisdictional dam definitions and criteria and therefor is not a jurisdictional dam. The supportive evidence for the case of a non-jurisdictional dam is presented and discussed as well as how the levee fits FEMA levee definitions and criteria.