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<br />a~1998 <br /> <br />Between 1943 and the early 1950's when John Martin Reservoir was <br /> <br /> <br />storing water for later use, the outflow at the state line averaged <br /> <br /> <br />237,160 acre-feet a year. In the early 1950's, the flow at the state <br /> <br /> <br />line decreased materially, and this has continued throughout 1966, <br /> <br /> <br />exclusive of the 1965 flood flows the average annual amount was <br /> <br /> <br />133,300 acre-feet. It is important to note when comparing the first <br /> <br /> <br />and last periods that the flows at the state line have been reduced by <br /> <br /> <br />an average of 60,950 acre-feet. This reduction is no doubt the result <br /> <br /> <br />of a combination of factors among which are the greater util ization <br /> <br /> <br />of surface fiows by storage in John Martin Reservoir. depletions result- <br /> <br /> <br />ing from the use of ground water by pumps. and increased non-beneficial <br /> <br /> <br />use by phreatophytes. When corrections are made for the larger outflow at <br /> <br />the state 1 ine between 1943 and the early 1950's. the apparent reductions <br /> <br /> <br />in the flow at the state line average 105.000 acre-feet per year. <br /> <br /> <br />When the Frying Pan-Arkansas Project is completed by the Bureau <br /> <br />of Reclamation, it is anticipated that imports wil I average 71,900 acre- <br /> <br /> <br />feet per year for a series of years with runoff similar to that for the <br /> <br /> <br />1928-1955 study period. The Bureau studies indicate that potential <br /> <br /> <br />increased importations averaging 7.200 acre-feet per year can be made <br /> <br />by the Wurtz, Ewing and Columbine systems. The ultimate importations <br /> <br /> <br />by the Independence Pass system was computed by the Bureau to average <br /> <br /> <br />50.500 acre-feet per year, but most of this has been diverted historically. <br /> <br /> <br />Evaporation losses from project reservoirs have been estimated at 7.700 <br /> <br />acre-feet per year by the Bureau of Reclamation. <br /> <br />About 34.000 acre-feet of the above mentioned importations will <br /> <br /> <br />be used by municipal ities. When corrections are made for return flow <br /> <br /> <br />from municipal systems supplied by the Frying Pan-Arkansas Project and <br /> <br /> <br />the additional potential importations are added, an average annual <br /> <br /> <br />new supply of about 81,000 acre-feet per year for agricultural use may <br /> <br /> <br />be expected. <br /> <br />Inadequate records of tributary inflow along with the erratic <br /> <br /> <br />nature of this flow precludes a determination of the amount of tributary <br /> <br /> <br />inflow into the basin below Canon City. It is therefore recommended <br /> <br /> <br />that accurate and continuous records of tributary inflow of the major <br /> <br /> <br />tributaries be obtained. Where applicable. corrections for operational <br /> <br />- 15 - <br />