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Show CHAPTERS RESERVOIR SCREENING MODELS The water resources literature is replete with models for the optimization and simulation of reservoirs. By and large, most of the effort has focused on models of reservoir operation and management. Screening models for reservoir design can be useful in the identification of efficient system configurations and component capacities. This chapter presents a nonlinear programming model for the selection and sizing of reservoirs, from a list of candidate sites. Multiple purposes and several sites are considered. The focus here is not on the development of optimal reservoir operation rules. Instead, it is on the development of an algorithm that explicitly considers reliability of use, and hydrologic, physical and economic parameters to enable a preliminary screening of candidate reservoir sites, and hydropower generation capacities. Most of the quantifiable factors relevant to a public agency's analysis of such a problem are embodied in the model. The result is a compact nonlinear optimization problem that exhibits little more than linear growth in the mathematical problem size with increases in the number of sites, or number of months of operation considered. Significant savings in computational memory requirements over other formulations are offered at the expense of nonlinear functional forms. The general modeling criteria identified are first presented. Literature on modeling efforts that are directly related to the objectives of this chapter is then briefly reviewed. The model formulation developed is then presented in the context of the modeling criteria specified. The solution technique employed for this formulation is then briefly discussed. Applications of the model presented to sites from the Lower Bear River Basin and from Salt Lake County conclude the presentation. 5.1 Modeling Criteria The modeling goals and assumptions that form the basis of the formulation presented are briefly reviewed in this section. The objective of the model formulated is to determine a set of optimal storage capacities for the candidate set of reservoirs that maximizes the expected net annual revenue from the construction of the reservoirs and hydropower generation facilities. Net annual benefits are defined as the difference between expected total annual benefits from project construction from the provision of M& I water, irrigation water, hydropower, flood control, and recreation, and the total annualized capital, operation and maintenance costs of the reservoirs, generators and conveyance facilities. These optimal values need to be determined, subject to a set of constraints. The principal constraints considered explicitly ( 1) Limits on total reservoir storage capacity for each site. ( 2) Filling each reservoir at the end of the operation period. ( 3) Maintaining prescribed ratios of conservation storage to total storage at each site. ( 4) Meeting M& I demands for each area with specified reliability. ( 5) Meeting Irrigation demands for each area with specified reliability. ( 6) Providing adequate flood storage in the system. 102 |