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Chapter 11:Hazard Analysis—Dam Failures <br /> • Failure occurs during a sunny day with dry downstream conditions <br /> • Failure occurs when dam is at its maximum capacity <br /> • Failure occurs by piping failure halfway up the face of the dam <br /> • Spillways and dam outlets are inoperable at the time of the breach <br /> In addition to the dam failure inundation maps, the study will provide individual dam <br /> assessment reports with the following information: <br /> • Total maximum water depth <br /> • Time of maximum water depth <br /> • Time to first inundation <br /> • Depth at first inundation <br /> • Water velocity. <br /> • Impact to population including number of people potentially impacted downstream <br /> • Impact to transportation including water depth and velocity at bridges and road <br /> crossings <br /> • Impact to building infrastructure and replacement cost value <br /> • Impact to critical facilities (schools, hospitals, fire and police stations, government <br /> buildings, airports/seaports, and shelters) <br /> As of the third trimester of 2009, PDC has completed the dam failure inundation maps and <br /> individual assessment reports for all one-hundred-thirty-five (135) dams. In 2010, DLNR <br /> evaluated and approved these maps and reports for release to County of Hawaii Civil <br /> Defense, for official use only. The Hawaii County Police Department, responsible for <br /> evacuation procedures, utilized the reference dam inundation maps to develop potential dam <br /> break evacuation maps. An example map for the Waimea area(and downstream) is shown in <br /> Figure 11-9. It is expected that the documents will be released to the public in early 2011. <br /> 11-11 Hawaii County Multi-Hazard Mitigation Plan <br />