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~ Page 4 October 10, 1989 Joyce Neville would be possible. Therefore, the proportion of the contribution of water from this amendment compared to the flow in Williams Canyon should not greatly differ whether the storm is a 5 year or 500 year storm. It still amounts to only a fraction of a percent of the total flow in the basin. As for the sediment, please note that the protection of the existing, natural ground is quite low and there is clear evidence that a considerable amount of sediment load would be derived from the existing surface. Although there might be somewhat of an increase in sediment during very high flows, please recognize that most streamside plants grow there because they are tolerant of sediment burial. In fact, Cottonwood trees require scouring, sediment laden floods to reproduce naturally by seed. Sediment harms plants where it is deposited around plants that are intolerant of sediment, streamside plants evolved in the presence of sedimentation events and, unless it is very severe, are little affected by sediment and can actually be improved, with mild sedimentation, through the introduction of additional nutrients and organic matter. We also wish to inform you that the approximate boundaries of the mining areas have been flagged with "hot pink" flagging placed on trees and bushes. Many of these flags should be visible with binoculars or a spotting telescope from the Cave of the Winds area. We do wish to inform you, however, that the precise boundary has not been surveyed as mining limit boundaries are always considered approximate. During the mining process many adjustments are often necessary to correct for variations in the rock structure. However, along the boundary where the mining and permit boundaries are nearly congruent, the permit boundary and any setbacks are closely observed. It is mainly where the mining and permit boundaries are very widely separated where the most adjustments are made. In the course of flagging the boundary we found a previously unrealized benefit in mining the South Peak first. Because of inaccuracies in the visual line of sight analysis it was noted that by mining the South Peak first (the area least visible from Cave of the Winds), the extent of the mining of the north end of the amendment can be closely controlled. Currently we cannot see through the mountain and are at the mercy of the map accuracy to predict mining limits. But by removing [he mountain we will be able to determine exactly where the mining must stop to avoid being seen from the Cave of the {finds. Previously, mining the north end after the South Peak was just a good way to approach the site. Now, it appears to be mandatory it be mined in that way.