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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />irrigation water requirements for the four major crops in the district. The results of these <br />calculations are presented in Table 5-2. This analysis shows that there would be in excess of <br />220,000 acre-feet of water withdrawn annually to meet the full irrigation demand for the <br />approximately 128,800 acres of the four major irrigated crops (corn, wheat, sorghum, and <br />alfalfa) in the basin. This volume of water was estimated by inserting the weather data from <br />Springfield, Colorado into the Blaney-Criddle method. An irrigation efficiency of 85 percent was <br />assumed for these calculations. This level of irrigation efficiency reflects the significant number <br />of center-pivots equipped with drop nozzles that are present in the district. <br /> <br />For comparison purposes, 1999 weather data from the Walsh weather station was used to <br />estimate the volume ground water pumped in 1999. These volumes for each crop type are <br />presented in Table 5-3. The total annual volume of water estimated to be withdrawn would <br />increase to nearly 227,000 acre-feet using the Walsh climatological data. Similarly, the 1999 <br />weather data for Springfield was used to estimate the ground water pumpage volume in 1999. <br />These volumes for each crop type are presented in Table 5-4. The total annual volume was <br />estimated to be approximately 218,000 acre-feet. This difference represents approximately <br />9,000 acre-feet increase using the Walsh weather data for 1999 and can be attributed to Walsh <br />being approximately 600 foot lower in elevation than Springfield. <br /> <br />The amount of precipitation received during the 2000 growing season in the District was slightly <br />more than half of the amount received in 1999. The amount of precipitation measured at the <br />Plainsman Research Center (Center) near Walsh from April to October of 2000 was 10.36 <br />inches that included 3.74 inches in October. For the same period in 1999, 19.6 inches of <br />precipitation were measured at the Center including 3.70 inches in October of 1999. Table 5-7 <br />summarizes the estimates consumptive use (250,800 acre-feet) and the estimated ground water <br />pumpage(295,OOO acre-feet) using the measured precipitation received at the Center for the <br />2000-growing season. This amount is approximately 68,000 acre-feet more than was required <br />in 1999, using the Blaney-Criddle method. <br /> <br />The approximate number of hours that wells would need to be operated based upon meeting <br />the peak monthly demand. The seasonal demands for the primary irrigated crops (corn, wheat, <br />sorghum, and alfalfa) have been determined and are presented in Table 5-7 thorough Table 5- <br />10. The purpose for presenting this information is to assist water users in determining their <br />actual pumpage. The higher the output capacity of the well the less amount of time required to <br />meet the gross irrigation requirement. The peak month and seasonal demand for the primary <br />irrigated crops are shown in Tables 5-7 through 5-10, respectively. For example, a 600-gpm <br />well would need to be operated approximately 2,170 hours to meet the needs of a 122-acre <br />center-pivot with corn. Similarly, a center-pivot irrigating wheat would need to be operated <br />approximately 1,170 hours to meet the seasonal water requirements. <br /> <br />V-3 <br />