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Mr. Jeffrey W. Schwazz, Esq. 10/14/01 Page 4 More evidence has recently been supplied to us by the Division of Minerals and Geology and the Denver Water Department in the form of digital photographs and an aerial photo taken in February, 2001. It is our understanding that digital photos were delivered by the UDFCD in a submittal it made to the DMG. Denver Water supplied the aerial photograph to counsel for Mobile Premix. The digital photos aze dated 1-18-01. (See Figure 1-7). They show snow on the ground, which would indicate that the date of the photo is probably correct. The photo also shows a breach in the river bank between the South Platte and the Bull Seep slough. This breach has an obvious gradient from the river side into the slough. The photos are oblique and not scaled so exact measurements of the breach width aze not available. However, I would visually estimate the breach to be approximately 10 feet wide and 4 feet deep. We confirmed that the photo we were supplied is at the location in question by going back to the field, taking a second digital photo on 10-10-O1 and cross checking the background tree line on the horizon for similarities. (See Figure 1-7). There is no doubt that this 1-18-01 photo was taken at the location of the breach in the riverbank that DMG asserts occurred on May 5, 2001. The aerial photograph that was taken about one month later also cleazly shows the breach as being formed into the slough neaz the end of concrete rubble or riprap on the river side of the bank. The horizontal location confirms that it flows into the slough and is near the location where the Bull Seep ditch enters the slough. It also confirms that the breach is located directly at the point of attack from flows in the South Platte River. This additional information further reinforces our opinion, as eazlier expressed to you in our letter report of July 12, 2001, that the location of the Bull Seep ditch had nothing to do with the failure of the South Platte River into the Bull Seep slough. This breach obviously occurred at a time when there would be minimal flows in the Bull Seep ditch, yet a breach exists nonetheless. This leads to no other conclusion than the bank failed from the riverside into the slough. We have been given no information that indicates that any repairs were made to this breach prior to the May 5, 2001 event. In light of this information, it is intuitive that the next time the river flowed above the elevation of the breach depicted in the January 18, 2001 photos, such flow would rapidly erode and widen the breach. If the breach went unrepaired, this would cause additional degradation and a lowering of the breach elevation to the point that each subsequent flow event in the river that exceeded the elevation of the breach would flow into the slough and continue to erode the Bull Seep Slough. The location of the breach coincides almost exactly with the point of attack from the river and the location where the UDFCD made repairs after the May 5'h event. Based on the information that we have reviewed, it is my opinion that the breach, which was in evidence as eazly as January 2001, would have occurred in the riverbank at this location regardless of the location of the Bull Seep ditch. The fact that a small breach existed several months before the flood should be sufficient to confirm this. The levee breached into the portion of the Bull Seep Slough that was created during the 1973 flood event. Once the breach occurred, the remaining portions of the riverbank likely failed to the South Platte River "head" cutting back along the existing channel.