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<br />during the flood. In other words, a "bulking factor" was taken into account when making the <br />discharge estimates. Future studies will be conducted to determine the amount of debris and <br />sediment that may have affected the discharges. <br /> <br />The possibility of deep scouring of the channel bottoms during the flood peaks was not taken into <br />account. Typically during a flood event, channels that have an erodable bed will scour out during <br />the rising limb of the hydrograph (flood flows are increasing), and then will fill back in during the <br />receding limb of the hydrograph (flood flows are decreasing). Previous studies have shown that <br />discharges can sometimes be underestimated by not taking into account the increased channel <br />capacity (from scouring) during the peak flows on some streams. This situation may be applicable <br />on Buffalo Creek and its tributaries, and should be investigated at a later time. <br /> <br />The peak discharge estimates are shown in Table I, and are presented on the following figure. In <br />addition to the July 12 peak flow estimates, the lOO-year flow values from the Jefferson County <br />Flood Insurance Study (FEMA, 1986) are included in the table for comparison, where applicable. <br />The preliminary discharge estimates will be reviewed, refined if necessary, and published in a later <br />report. <br /> <br />Table 1 <br />Summary of Estimated Peak Discharges <br />Vicinity of Buffalo Creek, Colorado <br /> <br /> CWCB USGS Jeffco Flood <br /> Estimated Estimated Insurance <br />Stream Name Location Peak Peak Study IOO-yr <br /> Flow (cfs) Flow (cfs) Flows (cfs) <br />N. Fork South Just d/s of confluence 16,600 10,000 to 2,300 <br />Platte River with Buffalo Creek 14,500 <br />Buffalo Creek Just u/s of mouth 17,100 8,000 to 630 <br /> 16,000 <br />Buffalo Creek VIS of confluence with 9,600 N/A N/A <br /> Spring Gulch <br />Buffalo Creek VIS of confluence with 5,700 N/A N/A <br /> Shinglemill Creek <br />Buffalo Creek VIS of confluence with 520 N/A N/A <br /> Morrison Creek <br />Buffalo Creek Culvert at CR 550 and 120 N/A N/A <br /> CR 543 <br />Sand Draw Just u/s of mouth 7,100 6,000 to 675 <br /> 7,000 <br /> <br />6 <br />