2009-12-18_REVISION - C1981008 (4)

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United States Department of Agriculture o N RCS Natural Resources Conservation Service Jim Boyd, Resource Conservationist P. O. Box 29 Norwood, CO 81423 pm.boyd@co.usda.gov 970-327-4245-OFFICE 970-327-4247-FAX March 4, 2008 Division of Reclamation, Mining and Safety Department of Natural Resources 101 South 3'd Street, Suite 301 Grand Junction, CO 81501 Dear Concerned Parties: I have been asked to "weigh-in" on the amount of reclaimed irrigated cropland that could be practically irrigated in the Nucla area with a certain number of shares of Colorado Cooperative (CC) Ditch Company water. In particular, the land and water in question is owned by the Morgan family, and is being leased for coal mining by the New Horizon Mine. Fifty shares of CC Ditch Company water, with a full head in the ditch, is a steady supply of about 1.5 cubic feet per second (cfs) for most of the growing season. This is the amount of water that is presently available for the irrigation of reclaimed lands owned by the Morgans. Enclosed is a Sideroll Sprinkler Design Worksheet detailing the specifications of a sideroll sprinkler that could sufficiently irrigate approximately 23.5 acres of Alfalfa growing in Nucla on reclaimed Barx Fine Sandy Loam soil. The sideroll is 1280 feet long, and will serve a crop field with dimensions of 1320 feet by 780 feet (23.5 acres). The sideroll has 33 nozzles along its length, each one distributing 6.5 gallons per minute (gpm); thus the sideroll uses a little less than 0.5 cfs of irrigation water while operating. The common spacing between sideroll sets (or moves) is 60 feet, so there will be 13 irrigation sets within the 780 foot field dimension. Also enclosed is a proposed irrigation schedule illustrating the feasibility of growing about 71 acres of alfalfa on the reclaimed Barx Fine Sandy Loam soil, using approximately 1.5 cfs of CC Ditch Company water. In the irrigation schedule I utilize three sideroll sprinklers of equal size and design, each serving 23.5 acres, to irrigate a total of about 71 acres of alfalfa. (One sideroll per 23.5 acres.is required to meet the "turn-around time" of 16 days needed to satisfy the peak consumptive water use of alfalfa, while using 23 hour irrigation sets - see discussion below). Each sideroll is designed to meet the peak consumptive water use of alfalfa in mid-summer in the Nucla area (0.25 inches per day). Also, I assumed that the reclaimed soil will have an average depth of 4 feet, and the alfalfa crop will utilize the available water stored in all 4 feet of this - - reclaimed soil (about 7.6 inches) for its consumptive water use. When the alfalfa crop uses 50% of the available stored water in the soil (3.8 inches) it is time to irrigate and re-fill the soil profile. The Natural Resource Conservation Service works in partnership with the American People to conserve and sustain natural resources on private lands. An Equal Opportunity Provider and Employer.