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Given the above conditions, the time between successive irrigations of alfalfa in the heat of the <br />summer is about 16 days. I recommend 23 hour sets per irrigation so that the water is applied at <br />a modest rate, i.e., the application rate does not exceed the soil intake rate. Therefore, it takes 13 <br />days to irrigate 23.5 acres with one sideroll. This allows two days off from irrigation every 15 <br />days, for such things as sprinkler repairs, or to just "go fishing." As is evident in the irrigation <br />schedule, a few days of "shut down time" each month for repairs and maintenance of the system <br />is an important management factor that I have included. <br />Lastly, each sideroll is designed to fit the geometry of the field it is going to serve. - I assumed <br />that rectangular fields would be re-established after mining so that a 1280 foot sideroll would <br />irrigate a quarter-mile wide field. A sideroll this length will have 33 nozzles (40 feet apart), each <br />putting out 6.5 gpm for a total of about 215 gpm, or 0.48 cfs. If three siderolls are designed <br />similarly, then the total water use will be 1.43 cfs. In this scenario there is not sufficient unused <br />water to run another sideroll of any length. Therefore, the only way to fully utilize the 1.5 cfs <br />available would be to make the three siderolls longer (on multiples of 40 feet) if the geometry of <br />the reclaimed fields allows it. Realize though that longer siderolls are harder to move and <br />require more maintenance. The other option would be to provide enough additional irrigation <br />water, approximately 0.41 cfs, to supply the water needs of a fourth quarter-mile sideroll. If this <br />were to occur then there would be sufficient water (a little less than 2 cfs) to run four siderolls, <br />and irrigate almost 95 acres of alfalfa. <br />The above recommendations are based on the United States Department of Agriculture - Natural <br />Resources Conservation Service (USDA-MRCS) irrigation design and crop management <br />standards and specifications. They are scientifically defensible principles and could be <br />realistically applied to the Morgan property. If you have any questions regarding these <br />recommendations or need further assistance please contact me. <br />Sincerely, <br />Jim Boyd, MRCS Resource Conservationist <br />cc. Western Fuels-Colorado <br />Morgan Family