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The Williams Fork study included discussion on a paleoflood analysis which had been provided <br />for the Williams Fork drainage basin. The conclusion of this analysis was that there was no <br />evidence observed within the Williams Fork drainage basin that suggested any significant flooding <br />beyond what could be attributed to snowmelt runoff. As part of the analysis for the Henderson <br />Mill drainage, paleoflood data were collected at about a dozen locations within the Henderson <br />Mill tailing pond watershed. No evidence of significant flooding was observed at any of the sites. <br />Figure 4 shows the sites visited in the Henderson Mill basin and the sub - basins associated with the <br />sites. The data have not been analyzed at this time. When the analysis is completed, the results <br />will be provided. The conclusions from the paleoflood analysis for the Williams Fork study as <br />stated above do apply. This conclusion is consistent with other high altitude watersheds in the <br />Rocky Mountain region. <br />Watershed Characteristics Relative to PMP Considerations <br />The Williams Fork watershed is bounded by prominent mountain ridges. These essentially <br />continuous ridges present significant obstacles to low level wind flow and moisture intrusion on <br />all sides of the watershed except the northwest. Airflow entering the basin from all directions <br />except the northwest is strongly downslope, causing a pronounced warming and drying of the <br />airmass. The Henderson Mill tailing pond drainage basin location is within the region of strong <br />downslope for the Williams Fork Mountain range under southwest wind flow. This rain shadow <br />location limits the potential for extreme rainfall over the basin. <br />Each topic that was addressed in the PMP study for the Williams Fork study was reviewed by <br />AWA to determine if the conclusions were applicable to the Henderson Mill drainage. A brief <br />discussion is provided. <br />Page 6 <br />