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<br />Mr. Travis Smith, Superintendent <br />October 16, 2003 <br />Page 6 <br /> <br />. <br /> <br />July <br />August <br />September <br />October <br /> <br />3,200 <br />1,700 <br />1,200 <br />700 <br /> <br />These demand values were estimated in two ways. The April demand values were estimated <br />from inspection of the annual maximums of the combined daily diversions into the downstream <br />ditches during water years 1950-85. The demand values for May through October were <br />estimated as weighted averages for the native flow rates on days during 1968-2002 that the <br />storage reservoirs were in priority. ~ <br /> <br />. <br /> <br />Table 4 shows the results of our calculations for the water that was available under the <br />terms and conditions of the Tres Rios decree in the four years when Project Storage spilled. <br />The annual volumes ranged from 30,850 acre-feet in 1995 to 73,082 acre-feet in 1985. When <br />spread over the 57-year period, the water averaged 3,613 acre-feet annually, but it would have <br />taken a reservoir enlargement of about 73,000 acre-feet to realize this full amount. The average <br />yield would have been less with smaller reservoir enlargements~ <br /> <br />COMPACT STORAGE <br /> <br />. <br /> <br />As you know, the Rio Grande Reservoir was used by the State Engineer and the Rio <br />Grande Water Users Association to store and regulate "Compact water" in the early 1980s. The <br />District and the Rio Grande Water Users Association have agreements with the State Engineer <br />that allow the State Engineer to use Rio Grande Reservoir for this purpose. The objective of this <br />compact storage was primarily to minimize over-deliveries to New Mexico and Texas. Although <br />the concern about over-deliveries has been reduced somewhat since the 1985 spill of Project <br />Storage, the storage and regulation of compact water would have other benefits for the State of <br />Colorado and the Water Users. We can see benefits in three areas: 1) for regulation to reduce <br />fluctuations in the daily curtailments; 2) for regulation in high flow years to reduce delivery rates <br />and therefore conveyance losses below Del Norte; and 3) for storage of Colorado's credit water. <br />Although these benefits can be accomplished to some extent through the use of the existing <br />reservoirs in the basin, an enlargement of Rio Grande Reservoir would increase the reservoir <br />capacity available for these purposes and, if so managed would assure some opportunity to <br />achieve these benefits in years when the existing reservoir fills. <br />