2001-12-11_PERMIT FILE - C1981010A (4)

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COQV01[~T)OM ' • from Table 4-1, that difference was a fraction of a percent of the flow at Station 6 except for the 30 August measurement. As I noted in Table 4-1, tc.o of that day's measurements, especially the Williams Fork measurement, were rated at less than excellent. That day also exhibited the grea[est loss between 3A and 4 yet the smallest loss across the entire reach of interest. As was ' noted on the Discharge Measurement Notes at Station 1 on 31 August, the stopwatch was discovered to be faulty and the back- - up watch had to be substituted. It is probable that the measure- ments at Station 7 and perhaps Station 6 on 30 August were signi- ficantly affected by this. Due to this discrepancy, the loss across the entire reach on 30 August of only four cubic feet per ,. second was disregarded in the conclusions. The field notes are included in Appendix A. On 31 August the weather changed and became very windy, affecting measurements at Stations 3 through 6. The more erratic • ~ nature of those measurements reflects the decreased"accuracy i j ratings given to their results. It was thought that localized ground-water pump age may 1 have been the reason for such a sharp drop in river flow at one ~ point. An examination of the local well inventory at the Utah '' International mine headquarters shocued one well in the vicinity ~ of the loss. This turned out to be a domestic well whose maxi- , 3 mum pumping capacity could only have accounted for a small per- centage of the measured Loss. J " 4.2 Changes in Channel Storage ' The data from the continuous stream gage at S.H. 13 "are presented graphically in Figure 4-2. As can be seen from the graph, conditions were reasonably steady-state, particularly overnight. And for each complete day of record, flow measure- . ' ments were initiated prior to any drop in river stage. In order to calculate adjustments, an estimate of the time of travel over ~ 4-5 I