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Table 4 <br />Water District Default County/FIUC Assignments <br /> <br />Water District Default County/HUC <br />Combination <br />20 Rio Grande / 13010001 <br />21 Conejos / 13010002 <br />22 Conejos / 13010005 <br />24 Costilla / 13010002 <br />25 Sa uache/13010003 <br />26 Saguache/13010004 <br />27 Saguache/13010004 <br />35 Costilla / 13010003 <br />Comments and Concerns <br />As shown in Table 1, the climate across the San Luis Valley floor is relatively consistent. <br />Therefore, weighting a valley floor station more than another is unlikely to have a great <br />effect the irrigation water requirement. <br />The following addresses County/HUC combinations that warranted further investigation: <br />Two County/HUC combinations covered extensive areas with large differences in <br />elevations -Saguache/13010004 and Conejos/13010005. The diversion structure GIS <br />coverage indicated diversion structures in the higher elevations on both Saguache <br />Creek and the Conejos River. There was initial concern that these County/HUC <br />combinations would need to be split into two areas with different climate stations and <br />weights to accurately represent the two climate regimes. <br />A closer review of the USGS County maps for both areas showed that the high <br />elevation lands in both counties were located in the Rio Grande National Forest, and <br />we understand that it is unlikely that much irrigation takes place within the National <br />Forest. In addition, we reviewed information on the USGS streamflow gages located <br />on both rivers where they flow out of the higher mountains. The remark section of <br />the 1997 Water Supply Paper for Conejos River near Mogote indicated there are only <br />about 500 acres of hay meadows upstream from the station. The remark section of <br />the 1997 Water Supply Paper for Saguache Creek near Saguache did not provide an <br />acreage estimate, but indicated there are some diversions upstream for irrigation. <br />Based primarily on the fact that the upper elevations of both areas are in the National <br />Forest, we believe the diversion structures likely provide water to irrigate lands <br />located closer to the valley floor. The centroid for the irrigated lands was placed <br />accordingly, and one set of climate station and corresponding weights was assigned to <br />these County/HUCs. <br />appendE_cropcu.doc E-8 of E-9 9/21/99 <br />