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7 <br />T <br />a computer software package called seepW by Ge -slope International, Ltd. <br />The h drograph shorn in Fig. 1 was input as the boundary conditions on <br />the cree side of the levee. Through this analysis, it was possible to estimate <br />that the depth the wetting front propagates into the levee. During a flood <br />event in which water is impounded to an elevation of 5384 feet and the <br />ground water is at are elevation of 5380 feet in the ditch, seepage progresses <br />approximately one to two feet into the levee. During rapid drawd wn, <br />seepage progresses sufficiently to link the ground water to the surface <br />directly adjacent to the ditch. The critical flood stage condition is shown in <br />Figure A-5 and the linking of ground grater surfaces resulting from rapid <br />dr wd wn is shown on Figure A-7. <br />Figure A-12 shows the phreatie surface that results from floodwater <br />impounded at an elevation of 5384 feet during the lower ground grater <br />condition. <br />The analyses indicates that the time span over which the levee must retain <br />grater during a flood is sufficiently short that seepage through the levee is <br />negligible and pore pressures developed as a result of partial infiltration are <br />small. <br />Pinhole tests were performed on samples of the levee fill and foundation <br />soils. The samples tested classify as type ND -1 and ND-2 ND-2 and are non - <br />dispersive. These test results indicate that piping is unlikely through and <br />underneath the levee. <br />Slo 51a .. The stability of the levee was analyzed using the Bishop <br />Method of slices incorporated in a computer software package named <br />slopeW by e -slope International, Ltd. Theoretical factors of safety were <br />obtained for the critical levee section by considering steady state conditions, <br />FLATIRON COMPANIES <br />LEVEE AT DEEPS FARM FAIT 10 <br />cTLIT 25,385 <br />