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<br />be included in calculations for the discharge hydrograph at the dam axis. <br />Routing the Dam-Break Flood for Condition I <br />The results of routing the dam-break flood for Condition I are <br />shown in figure 4 in the form of discharge and elevation hydrographs <br />at Cranks Creek Dam axis and at Martins Fork Dam axis. <br />The impact of the flood wave on Martins Fork Dam resulted in a <br />28-foot increase in water surface elevation above the SDF peak, as <br /> <br />the inertia and kinetic energy components were transformed back into <br /> <br />a pressure energy. The peak discharge at Martins Fork was 190,000 cfs. <br />Four minutes were required for the wave to travel from Cranks Creek Dam <br />to Martins Fork Dam. <br />Two alternative methods for computing travel time, a wave celerity <br /> <br />computation based on initial depth and a forward characteristic computa- <br /> <br />tion based on cerlerity plus flow velocity, produced travel times of <br />6 minutes and 5.5 minutes, respectively. The travel time calculated by <br />the routing method used in the study appears to be reasonable, based <br /> <br />upon comparison with these values. <br /> <br />The peak outflow from Cranks Creek Reservoir, curve one of figure 4, <br /> <br />is 1,400,000 cfs. The value obtained by applying equation 1, 1,200,000 cfs, <br />compares favorably with this peak outflow. <br />The peak discharge is important because it influences the rate of <br />energy dissipation due to friction. This point was illustrated in the <br />study by first including all storage volume on Martins Fork mainstem, <br /> <br />upstream from Cranks Creek, then recalculating the routing with that <br /> <br />11 <br />