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<br />5-03. As a result of these studies the June 1921 storm was selec- <br />ted and approved for standard project flood determination at Las Animas. <br />Subsequent to this approval, studies were made of transpositions of the <br />June 1965 storm to determine the relative magnitude of that storm. The <br />1965 storm, as it occurred, produced larger amounts of total rainfall <br />and in some areas more intense rainfall than the 1921 storm. However, <br />when the two storms were transposed to the same area above Las Animas, <br />the 1965 storm transposition did not result in significantly higher <br />peak discharges and produced less total runoff. The severe cells of <br />the 1921 storm occurred generally above Las Animas and the transposi- <br />tion resulted in a gain in total precipitable water. The severe cells <br />of the 1965 storm occurred generally at lower elevations which resulted <br />in a reduction of precipitable water when transposed to higher eleva- <br />tions. It was concluded that the June 1921 storm would be more appro- <br />priate for standard project flood determination than the June 1965 storm. <br /> <br />5-04. In determining data for use in transposition to the 9,306 <br />square miles of area contributing above Las Animas, only that portion <br />of the June 1921 storm which conformed to the drainage area was con- <br />sidered. Pertinent data for the area encompassed by the 1921 storm, <br />as it occurred, are as f9110ws: <br /> <br />a. Total-area weighted effective inflow barrier elevation, <br />E s 6,700 feet, m.s.l. <br /> <br />b. Total-area weighted effective dewpoint, Dp = 73.76 <br />degrees or equivalent precipitable water from sea level up; W2s = 2.725 <br />inches minus (inflow barrier 6,720 feet) W of 1.326 inches - available <br />precipitable water, Wpa 1.399 inches. pe <br /> <br />c. Total-area weighted effective temperature contrast, <br />Tc = 14.0 degrees. <br /> <br />d. Total-area weighted effective 3lJpe factor (pTecipi tation <br />increase due to effective upslop~, SF ~ 1.037. <br /> <br />5-05. Pertinent data for the critical transposition over the <br />9,306 square miles of area above Las Animas for the month of June are <br />as follows: <br /> <br />a. Total-area weighted effective inflow barrier elevation, <br />E = 6,430 feet, m.s.l. <br /> <br />b. Total-area weighted effective dewpoint~ Dp = 74.00 degrees <br />0: equivalent precipitable water f~om sea level up; Wps = 2.763 inches <br />mInus (inflow_barrier 6,430 feet) Wpe of 1.290 inches. available precipi- <br />table water, Wpa of 1.473 inches. <br /> <br />c. Total-area weighted effective temperature contrast, Tc S <br />13.5 degrees. <br /> <br />18 <br />