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the Colorado Water Conservation Board (CWCB) Technical Manual No. 1 <br /> (8) . This method, which evaluates the flood characteristics of a <br /> region by a regression analysis derived from all the gaged records <br /> in that region, gave results which were appreciably lower than the <br /> SCS method and was not considered further.' <br /> On July 24, 1977, an observed flood within the area was estimated <br /> by Company personnel to have a peak discharge of about 1,100 cfs. <br /> Approximately 1,000 cfs of the peak discharge originated from a <br /> drainage area of about 2.74 square miles. This flood was evaluated <br /> by the SCS method and by the Rational Method to estimate the amount <br /> of rainfall and the recurrence interval of the storm that produced <br /> the flood. <br /> �~ using a 30-minute time of concentration and an appropriate curve <br /> number based on soil type and vegetative cover, the SCS method <br /> indicated that a storm with a 24-hour depth of 3.0 inches would <br /> r produce a flow of 1,000 cfs. The rainfall charts indicate a <br /> 100-year/24-hour storm would produce about 2.8 inches of rain. <br /> Therefore, it appears that the observed storm had a recurrence <br /> l : <br /> interval of slightly greater than 100 years by SCS methodology. <br /> i � using the Rational Method this same flood was computed to have <br /> ! originated from a storm with a 30-minute intensity of 1.9 inches <br /> ijper hour resulting in a total depth of 0.95 inches in a 30- <br /> l : 42 <br />