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Using the available water, as well as the water requirements for alfalfa fran the irrigation guide, the area that could be irrigated was determined and outlined on the aerial photo. Factors .Klich influenced the location of the proposed irrigated field were soils, topography, shape, distance fran the farm turnout, and other physical barriers. An irrigation system plan was then developed. This plan included pipe sizes and lengths, sprinkler pipe and nozzles, and estimated cost. With this data an irrigation water management plan was developed. The irrigation water management plan indicated how the system should be operated to maximize the irrigation efficiency. Crop budgets were then developed to show the expected returns to the landowners men using this cropping pattern and irrigation system. If the landowner wished, other alternative irrigation system plans were developed using the same process. Usually the alternatives developed included surface systems, sideroll sprinklers, and center pivot sprinklers. Unit cost, interest rates, leasing program cost, crop prices and yields were obtained fran local sprinkler canpanies and other local sources. These data were used in the development of the conservation plans. The crop prices were converted to normalized prices for display purposes in this report. The cost canparison display tables show the total cost, total cost/acre and annual cost/acre for purchase versus leasing. Also the net benefits/acre are shown for the acres served by the system. The graphs in the Appendix further reveal the cost and benefit canparisons. A linear regression best fit line was developed for the cost and benefit graphs in the Appendix. The best fit line smws the average cost or benefits for the various acreages. Land costs were rot included in the cost and return analysis. Surface Systems The Dolores Project lands are rot suited for surface irrigation systems. Slopes of the undulating topography range fran 1 to 12 percent, with the majority of tl1e area fran 3 to 6 percent. These slopes, with the soils found in the project area, limit the design lengths of nn to 400 feet or less. An extensive system of cross ditches or pipelines will be required to serve the area. Extensive land leveling will also be required. The expected efficiencies of the surface systems will be in the range of 35- 50 percent. This low efficiency will lead to under irrigation mere water is smrt and to potential drainage, erosion and salt problems as well as significantly lower yields. The cost of efficient surface systems generally will exceed that of sprinkler systems in the study area. Returns will be less than with sprinkler systems because the irrigation water management will be harder to achieve. Based on these reasons, surface systems are not recamnended as a viable alternative irrigation system. Sideroll Sprinkler Systems A design for a sideroll sprinkler system was made for all of the fields included in the study. Table D includes a sUllIIlary of the data collected. -10-