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<br />Dam Failure Flooding <br />As stated in the Hazard Identification section of this plan, Dam Failure Flooding is <br />included as a special subset of flooding because there are many dams within the planning <br />area, and some have failed in the past. The Planning Team has been able to document <br />four dam failures within the planning area; 3 within Weld County (Chambers Lake, 1907; <br />Latham Dam, 1973; and Prospect Dam, 1980, and one in Sedgwick County (Julesburg <br />Reservoir, 1917). <br /> <br />Determining the vulnerability to flooding from dam failure differs from "normal" riverine <br />flooding, in that the land areas that would be inundated in the event of a dam failure are <br />not typically displayed on the FEMA and CWCB flood hazard area maps. This is <br />because the retention structures, whether the primary function of the facility is for <br />irrigation or flood control, are usually some distance upstream from the communities and <br />users they provide for, and are in areas that have not otherwise been mapped. Colorado <br />law, however, requires that Class 1 dams have Emergency Action Plans (EAP), and that <br />failure inundation maps be prepared as part of the those plans. The Planning Team did <br />confirm the existence ofEAPs for the High Hazard dams. The emergency call-down <br />notification lists for downstream property-owners serves as the initial vulnerability <br />assessment for dam failure. The level of effort required by the communities to develop <br />the inventories of the 1 % mapped floodplain precluded completing detailed vulnerability <br />assessments for the dam failure inundation zones. Detailed dam failure inundation zone <br />inventories may be completed in the future, and are a recommendation of this plan. <br /> <br />Class 1 Hif!h Hazard Dams per County <br />Cheyenne 0 <br />Elbert 0 <br />Kit Carson 0 <br />Lincoln 1 <br />Logan 1 <br />Morgan 1 <br />Phillips 0 <br />Sedgwick 1 <br />Washington 1* <br />Weld 9 <br />Yuma 1** <br />11 County Total 15 <br /> <br />Source: CO-OEM <br />* Prewitt Reservoir is at the Logan-Washington County border and a failure would drain into Morgan <br />County. <br />** Bonny reservoir would drain into Kansas ifitfailed <br /> <br />29 <br />