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intact. In the second case levees were considered to be completely destroyed. The transition between the two storage-outflow curves was instan- taneous when river stages reached the top of the levee. For computational purposes it was necessary to make two passes through the computer to, route through the entire hydrograph. The results of the first pass (S + 1 routing) were utilized to the point just beyond the peak discharge. That furnished the starting storage with which to begin the recession computation using the second storage-outflow curve. There was some loss in volume because of basement and other storage in the city, but this was not a significant portion of the 225,000 acre feet of flood waters in the city at the time of the maximum flow of the river. DOWNSTREAM EFFECTS OF THE LEVEE OVERTOPPING The downstream effects of the levee overtopping at Wilkes-Barre were analyzed by routing the hydrographs which resulted from the two routings (with and without infinite levees in the Wilkes-Barre Reach) on dO\n1stream to Harrisburg. Both routings took into account the flows from intervening areas in computing the total Agnes flow at Harrisburg. The routed and intervening flows between Wilkes-Barre and Harrisburg were computed in the same manner for both of the hydrographs from the Wilkes-Barre Reach. tluskingum routing coefficients were used for all the reaches below Wilkes- Barre on the Susquehanna River and on its tributaries. The results of the two computed flows and the observed flows are shown in table 2. Figure 2c showed the comparison of computed and observed flows at Harrisburg for the levee nonfailure routing at Wilkes-Barre. The levee overtopping routing of the flows to Harrisburg was essentailly the same sl~pe with a reduced peak as noted in table 2. It is noted that the computed peak flows (for the levee overtopping case which occurred) differ from the observed peak flows by as much as 5