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<br />. 001)6 38 <br /> <br />. <br /> <br />. <br /> <br />larger percentage of ground water will be derived from salvaged evapo- <br /> <br /> <br />transpiration as the period of project operation increases. For example, <br /> <br /> <br />at the end of 10 years about 65 percent of the water salvaged was from <br />salvaged evapotranspiration and 35 percent was derived from storage. <br /> <br /> <br />After 50 years of operation, 84 percent was derived from eVaPotranspira- <br /> <br /> <br />tion and 14 percent from storage. The salvage water from induced Rio <br /> <br /> <br />Grande seepage amounted to only about 2 percent of the total amount <br /> <br />salvaged during the 50 years of simulated project operation. <br /> <br />This analog analysis is thought to tend to overestimate water 1eve~ <br />decline and Rio Grande effects, because of its assumption of continuous <br /> <br /> <br />ground water withdrawal, no contribution by upper leakage from the <br /> <br /> <br />artesian aquifer, and unrestricted hydrologic connection between the <br /> <br /> <br />unconfined aquifer and the ~io Grande. <br /> <br />Following complE!tion of this analog study. the Colorado State Engineer <br /> <br />expressed concern that the Bureau's well layout would cause unrealJ,stic <br /> <br />drawdowns in certain salvage areas. The GS then considered other <br />pumping patterns in an effort to limit the drawdown. A simple analysis <br />was made by redistributing the ground water withdrawals, taking into <br />consideration the transmissivity patterns. Transmissivity is the rate <br /> <br /> <br />at which water is transmitted through a unit width of aquifer under a <br /> <br /> <br />hydraulic gradient of unit. The analysis indicated that about 130 wells <br /> <br /> <br />could pump the proposed amount of water without causing excessive draw- <br /> <br />downs. <br /> <br />6 <br />