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<br />4. A spillway discharge rating table (in cubic feet per <br />second) for each foot of elevation above the spillway flowline crest <br />to the crest of the dam, including the equations for determining the <br />discharge rate; and <br /> <br />5. A table showing the reservoir area (in acres) and storage <br />capacity (in acre-feet) for each foot of elevation from the invert of <br />the outlet to the crest of the dam. Indicate the amount of dead <br />storage (in acre-feet), elevation of the invert of the outlet, and the <br />elevation of the flowline crest of the spillway(s). (All elevations <br />shall be based on USCGS datum, referenced to the invert of the outlet). <br /> <br />5.A.(5)(b) The inflow design flood (IDF) requirements for <br />determining the spillway capacity are summarized in the following <br />table. These requirements may be waived for good cause shown. Spill- <br />ways designed in accordance with these rules will not be required to <br />be enlarged due to subsequent revisions to the probable maximum <br />precipitation estimates, unless, in the opinion of the State Engineer, <br />there is a substantial threat to public safety. <br /> <br /> INFLOW DESIGN FLOOD REQUIREMENTS <br />Dam Class I II III IV <br />Dam Size <br />Large PMP .75 PMP 100 YR 50 YR <br />Intermediate PMP .50 PMP 100 YR 50 YR <br />Small PMP .50 PMP 100 YR 25 YR <br />Minor .50 PMP 100 YR 50 YR 25 YR <br /> <br />5.A.(5)(b)(l) New Large, Intermediate, and Small Class I <br />dams and enlargements shall have spillways capable of passing, as a <br />mlnlmum, the inflow design flood generated by 100 percent of the <br />Probable Maximum Precipitation, unless an incremental damage analysis <br />demonstrates a lesser inflow design flood is applicable, <br /> <br />5.A.(5)(b)(II) New Minor Class I dams and enlargements shall <br />have spillways capable of passing, as a minimum, the inflow design <br />flood generated by 50 percent of the Probable Maximum Precipitation, <br /> <br />- 14 - <br />