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<br />.. <br /> <br />enlarged due to subsequent revisions to the probable maximum precipitation estimates <br />unless, in the opinion of the State Engineer, there is a substantial threat to public safety. <br /> <br />INFLOW DESIGN FLOOD REQUIREMENTS <br />Hazard Classification Hieh Sieoificant Low NPH <br />Dam Size <br />Large .9PMP .75 (.9 PMP) 100 YR 50YR <br />Small .9PMP .50 (.9 PMP) 100 YR 25YR <br />Minor .50 (.9 PMP) 100 YR 50YR 25YR <br /> <br />5.5.6.1 New Large and Small High Hazard dams and enlargements shall have <br />spillways capable of passing, as a minimum, the inflow design flood generated by <br />90 percent of the Probable Maximum Precipitation, unless an incremental damage <br />analysis demonstrates a lesser inflow design flood is applicable. <br /> <br />5.5.6.2 New Minor High Hazard dams and enlargements shall have spillways <br />capable of passing, as a minimum, the inflow design flood generated by 50 percent <br />of 90 percent of the Probable Maximum Precipitation, unless an incremental damage <br />analysis demonstrates a lesser inflow design flood is applicable. <br /> <br />5.5.6.3 New Large Significant Hazard dams and enlargements shall have spillways <br />capable of passing, as a minimum, the inflow design flood generated by 75 percent <br />of90 percent of the Probable Maximum Precipitation, unless an incremental damage <br />analysis demonstrates a lesser inflow design flood is applicable. <br /> <br />5.5.6.4 New Small Significant Hazard dams and enlargements shall have spillways <br />capable of passing, as a minimum, the inflow design flood generated by 50 percent <br />of 90 percent of the Probable Maximum Precipitation, unless an incremental damage <br />analysis demonstrates a lesser inflow design flood is applicable. <br /> <br />5.5.6.5 New Minor, Significant Hazard and Large and Small Low Hazard dams and <br />enlargements shall have spillways capable of passing, as a minimum, the inflow <br />design flood generated by a 24-hour, 100-year rainstorm event. <br /> <br />5.5.6.6 New Minor, Low Hazard dams, and Large NPH Dams and enlargements <br />shall have spillways capable of passing the inflow design flood generated by a 24- <br />hour, 50-year rainstorm event. <br /> <br />5.5.6.7 New Small and Minor NPH dams and enlargements shall have spillways <br />capable of passing the inflow design flood generated by a 24-hour, 25 year rainstorm <br />event. <br /> <br />14 <br />