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<br />Figure 2 with Table 9 points out the highly significant r~sults of <br /> <br /> <br />these case studies. With an initial storage of 23,600 acre-feet and with <br /> <br /> <br />an annual input as lOt' as 2,400 acre-feet, t;he conservation pool could have <br /> <br /> <br />'been operated through the 1950's drought years in complete agreement with <br /> <br /> <br />the conditions of the contract. Hydrologic conditions preceding 1953 do <br /> <br /> <br />not contradict the initiac content assumption made for these case studies. <br /> <br /> <br />The hydrologic conditions following the year 1957 indicate that a refilling <br /> <br /> <br />of the conservation pool could have been accomplished. To keep the con- <br /> <br />clusions on the conservative side the conducted case studies indicate that <br /> <br /> <br />an annual water input of 2,500 acre-feet is more than adequate for meeting <br /> <br />the demand of the 1953-57 drought period. <br /> <br />It must be noted that the annual input requirement indicated by the <br /> <br /> <br />drought analysis is significantly below that ShOI~1 by the statistical <br /> <br /> <br />analysis of the evaporation losses alone. Such a finding was anticipated <br /> <br /> <br />and can be explained by the physics of the phencmena involved. The lake <br /> <br /> <br />evaporation is proportionate to the air temperature and inversely propor- <br /> <br />tionate tc the precipitation. The runoff in the South Platte basin is <br /> <br /> <br />basically derived from sn01'ffielt; that is, winter and spring precipitation <br /> <br />reaching the high-mountain region of the watershed. The importance of the <br /> <br /> <br />temperature is limited to the snowmelt period only, reflecting in the length <br /> <br /> <br />of the snol'ffielt runoff in the streams. <br /> <br />The significant difference between the methods of analysis must also <br /> <br /> <br />be emphasized. The evaporation data were statically analyzed distrubing <br /> <br /> <br />the time sequence of the individual events, For this analysis annual evap- <br /> <br /> <br />oration data were organized in a decreasing order by magnitude to complete <br /> <br /> <br />the frequency analysis. To overcome this shortcoming of the frequency <br /> <br /> <br />analysis, three-and five-consecutive-year sequences were also analyzed by <br /> <br /> <br />the same method. By doing this, some temporal information of the data is <br /> <br /> <br />retained; however the number of data points are significantly reduced. <br /> <br /> <br />As it was pointed out earlier, high evaporation losses and low stream <br /> <br /> <br />runoff are caused by largely different factors. This in itself makes it <br /> <br /> <br />extremely unlikely that low-runoff-year sequences ,.ill coincide with the <br /> <br /> <br />highest evaporation years. <br /> <br />- 18 - <br /> <br />M. W. BITTINGER AND ASSOCIATES, INC, <br />