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<br />gage u~d to develop the diagram were not adjusted for the <br />transmountain return flows which have passed the gage. It <br />is believed that these return flows increased significantly <br />during ,the 1949-1984 period, corresponding to a significant <br />increase in transmountain diversions during this same <br /> <br />period. without quantifying and adjusting the Las Animas <br /> <br />gage for transmountain return flows, which Colorado has <br />refused to cooperate in doing, valid conclusions about the <br /> <br />consistency of native inflow to John Martin Reservoir cannot <br /> <br />be made. <br />...~-_.----.- <br /> <br />I <br />I vs. <br /> <br />The mass diagra~ of the Arkansas River at Las Animas <br />Canon City shows a relatively constant slope until 1943 <br /> <br />which corresponds to the start of John Martin Reservoir <br />operation. See, Graph 4C, Ref. 11. Further declines are <br />noted starting in about 1948 and 1958. The slope gradually <br /> <br />increases starting in about 1966 and increases again <br /> <br />starting in 1979. The changed slope during the 1950s <br /> <br />corresponds to the time when the Compact became effective <br />and also when significant development of alluvial wells <br /> <br />occurred upstream of John Martin Reservoir. The decline <br /> <br />during the early 1960s corresponds to a drought period. <br /> <br />Significant increases in transmountain diversions, accom- <br /> <br />panied by resulting increased return flows, started about <br /> <br />1968. The flows at Las Animas have not been adjusted to <br />account for these return flows. Such adjustments could <br />significantly impact the slope of the diagram. The diagram <br /> <br />I reflece, ehe cumulaeive impace, of chao.ed admini'eraeion <br /> <br />under the compact, depletions caused by alluvial wells, and <br /> <br />-17- <br /> <br />'" <br />