Justification for the construction of water resource projects in developing countries has been traditionally based on benefit-cost analysis. This dissertation focuses on the standardized cost-effectiveness analysis for the planning, design and operation of water resource projects in developing countries and in particular southeastern Mexico. The "best" system is determined in terms of goals which reflect the physical, economic and social conditions of the region. The planning process starts by identifying goals which the water resource system or systems are desired to meet. These goals are then mapped into specifications in which the project needs are represented. Next, criteria or measures of effectiveness relating specifications to system capabilities are defined. These criteria are quantitative and qualitative. District alternative systems to meet the goals are defined and then their capabilities in terms of the measures of effectiveness are determined. The alternatives are then compared using both quantitative and qualitative measures of effectiveness. Then, using either a fixed-cost or fixed-effectiveness approach, the alternative system which most nearly satisfies the desired goals is selected. This study uses a real water resource system from which real decisions will be made. The methodology suggests improved ways of defining goals and criteria in developing countries and sets forth a concise framework upon which developing countries may base future water resource planning, design and operation.

A complete methodology for long-term water supply planning is presented. Based upon the characteristics of the water resources development planning problem (nonlinearity of cost functions, and hydrologic variables), the author rejects the seeking of "optimal" solutions and supports the seeking of "good enough" solutions. To answer the questions that are involved in long-term water supply planning, it is proposed to break down the problem into two simpler ones to be solved in a sequential fashion. Although mathematical guarantee of optimality cannot be assured, the introduction of physical and engineering constraints greatly increases the confidence in the final results. The proposed methodology allows deep analysis of the hydrologic aspects involved in water resources planning. The depth of hydrologic analysis is only restricted by available data and technology. In this respect, a method for synthetic generation of monthly runoff records in ungaged streams is proposed. An application of the methodology to the development of a Mexico City water supply plan is presented in full detail to appreciate its usefulness. Mexico City population forecast for the year 2000 is 28 million people. The estimated water demand in that year is 105 m³/sec, more than twice the present water supply of 50 m³/sec. To satisfy this demand, water has to be brought from four basins more than 150 km distant, and located at elevations more than 1,000 m below Mexico City's elevation (2,300 m above mean sea level). The water supply plan which resulted from this study indicates the most recommendable sequence for the development of the four basins, and the amount of water to be obtained from each one.