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r <br />The difficulty in confirming the source of water feeding the seeps is that the <br />bottom flow line) and water surface in the ditch is at about the sane <br />elevation or only slightly above the elevation of the seeps. This suggests <br />there is little or no water head to cause water to move from the ditch to the <br />seeps. This further suggests the seeps are more likely ground water fed. <br />Inspection of each of the seep locations on July 29 revealed the water exciting <br />from the seeps was clear and there was water in Dry creek Ditch . This <br />observation confirms that the water exciting from the seeps is not moving soil <br />particles from the ground. if the water had been moving soil particles, the <br />water would have been cloudy. <br />The 100-year flood episode will cause a water level on the creelside of the <br />levee that will increase the water head attempting to cause ground grater to <br />move under the levee. To the extent the ditch provides a mechanism for <br />surface water to charge the ground water, this charging will occur with <br />respect to the ditch as well as with the shallow ground water. The quantity <br />of water exciting from the seeps will increase some. However, the ground <br />under the levee includes a high percentage of larger rocks and gravel that <br />are densely compacted with a finer sand matrix that is resistant to piping. <br />In addition, the distance the water would need to travel from its entrance <br />point outside the levee to its exit point at a seep is more than Flo times the <br />increase in water head caused by the short duration flood event (see <br />Appendix . Further, the exit gradier'ts calculated at Stations 111 +00 and <br />145+00 were 0.01 and 0.02 respectively (see Appendix D). These physical <br />conditions are not conducive to piping. In our opinion, the seeps are not <br />presently affecting the structural integrity <br />of the levee and the integrity of the levee will not he affected by the 1 00-year <br />flood event. <br />The levee does not permanently hold back water. Seepage is mostly a <br />consideration during critical flood stages. Seepage through and under the <br />levee was analyzed using a transient finite element method incorporated in <br />FLATIRON COMPANIES <br />LEVEE AT DEEPE FARM PIS` <br />CTUT 25,385 <br />