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The task memos describing in more detail the consumptive use numbers for <br />other uses are the following: <br />Upper Colorado River Basin ITask Memo 2.09 -10 <br />White River Basin ITask Memo 2.09 -11 <br />Yampa River Basin ITask Memo 2.09 -12 <br />San Juan and Dolores River Ba Task Memo 2.09 -13 <br />2.1 Issues for Review <br />In calculating the crop CU the following issues were raised. If you are using the <br />crop CU numbers we encourage you to review the individual task memos for <br />each river basin where more detail is provided. The following are some of the <br />general issues raised on those task memos: <br />The results for the CU Model indicate a fairly common pattern of middle and late <br />growing season shortages. Some of the shortages might be caused by the fact <br />that no soil moisture is being modeled. These shortages could reflect the practice <br />of having spring diversions in excess of what is needed to meet the IWR in the <br />Spring, in order to replenishing the soil profile from losses through the winter. <br />This soil moisture is used in the middle and late growing season when the <br />diversions are less than the IWR. This pattern of consumptive use shortages <br />indicates that using a soil moisture budget might yield better results in the future. <br />The set of weather station weights was assigned based on the location of the <br />structure (i.e., county -huc where the structure is located) and not the location of <br />the area being served (except for the San Juan and Dolores). It may be useful in <br />the future to assign weights based on the location of the majority land -area <br />served by each structure. <br />The weights assigned to each weather station serving a county -huc are based on <br />the area of the county -huc served by each weather station. This is probably a <br />good assumption when modeling the whole irrigated area, but could introduce <br />some errors when modeling individual diversion structures. The reason for this is <br />that a structure might be located in an area of the county -huc that is represented <br />by only one weather station. When modeling individual diversion structures, <br />consideration should be given to further breaking the county -huc areas by the <br />zones where each weather station could be applied. <br />If any ditches are considerably water short but historically divert small volumes of <br />water compared to Head Gate Requirements (which are computed based on the <br />IWR values and the efficiency), the diversion records and the area assigned to <br />these ditches should be considered for future review to determine the cause of <br />these discrepancies. <br />If any ditches serving irrigated areas have a large discrepancy between the <br />historic diversion and the calculated Head Gate Requirement, the diversion <br />records and the area assigned to these ditches should be considered for future <br />review to determine the cause of the discrepancy. <br />