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Mr. Travis Smith, Superintendent <br /> October 16, 2003 <br /> Page 6 <br /> July 3,200 <br /> August 1,700 <br /> September 1,200 <br /> October 700 <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 /> 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 /> COMPACT STORAGE <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 />