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4. 3. Procedures for Comparative Analysis a. Comparison to he Based on Phase 1. As mentioned, the project will be built in 3 separate phases. Both CWCB funding and NRCS funding for the project are being supplied for Phase 1 only, at this time. The cost comparison between the two structural alternatives will be based upon the facilities needed for Phase 1, rather than comparing the entire project. This is done in part, for convenience and simplicity, since this will allow use of a single bid schedule for comparison. Since the construction methods for Phase 2 and Phase 3 will be very similar to that required for Phase 1, the results of the cost comparison between the two alternatives should apply to all phases. b. Use of Decision Matrix. For making the final comparisons, both economic and non-economic factors will be compared using a Qualitative Evaluation Matrix (decision matrix). The procedure for preparing the decision matrix is explained in a later section. As mentioned, monetary cost includes both capital investment costs and annual costs. c. Basis for Unit Costs. Each of the projects was broken down into individual components and unit costs were estimated for each component. Unit costs used in this report were ()btained from bid tabulations on projects similar to the proposed alternatives. In addition, material costs were obtained from suppliers and installation costs were estimated using that data. It is assumed that construction will take place during the non-irrigation season when the water table has dropped. For each tabulation, a 10% contingency has been added to the construction cost to allow for unforeseen problems, and a 5 % cost has been added for engineering, legal, administration and interest during construction. d. Project Life Cycle An important consideration in estimating annual costs is the project life cycle of each alternative. It is estimated that the pipeline will have a life cycle of 40 years and the reinforced concrete lining will have a life cycle of approximately 30 years. The concrete lining is exposed to the weather and elements, and will be subject to freeze-thaw cycles. In addition, there is more potential for settling and frost heave in the concrete ditch as compared to a pipeline. Annual costs have only been tabulated for the repayment period on the CWCB loan; however, the shorter life cycle of the open ditch must be considered in the Decision Matrix. Capital Improvement Costs Alternative A-I (pipeline). This alternative will consist of replacing the existing ditch with a pipeline. Alternate bids are provided in the NRCS V-10 I I I I I I I I I II I I I I I I I I I