Journal of Water Resources Planning and Management

The managers of large‐scale, surface‐water reservoir and delivery systems are required on a daily basis to make complex operating decisions. To assist in that decision process, a computational methodology is presented for determining the optimal operation of a general surface‐water resources system of water storage and conveyance facilities. The system is assumed to be operated for hydroelectric power generation, water supply, flood control, and low flow augmentation. The daily operation of such a system is represented as a deterministic, nonlinear optimization problem, with the decision variables being the average daily reservoir releases, water diversions, and pipeline and canal flows. Successive linear programming (SLP) is used to iteratively change the daily reservoir releases to improve system performance. The SLP algorithm converges to an operational policy satisfying the necessary conditions for optimality. The algorithm, incorporated into the MONITOR‐I computer program, is applied to the Lower Rio Grande System in Texas, and the results reviewed.

Stormwater detention basins are increasingly being used to control both urban flooding and nonpoint urban pollution. In order to design such systems effectively some type of design algorithm is needed. Two different dynamic programming formulations are examined for use in the development of a general design algorithm for dual purpose detention systems. Both formulations can be used to determine the locations and required storage for each detention basin as well as the required dimensions of the basin and the associated outlet works. Importantly, the proposed formulations allow the inclusion of pollutant loads and associated constraints into the overall stormwater management problem.

The professed goal of World Health Organization—to supply potable water to the poorest of the poor in the developing countries by the year 1990—appears to be quite an optimistic one in view of the existing situation in the developing countries, where potable water is still out of the reach of 80% of the populace. Supplying potable water to the rural population in these countries is quite a gigantic task owing to lack of physical and institutional resources. Any major effort at providing safe potable water to rural populations should first aim at improvement of the small community water supply systems. Small community water supply systems in these countries generally include: (1) Groundwater supplies; (2) rain water storage basins; and (3) surface water storage basins. Existing technologies of small community water supply systems in Indonesia and India are discussed and recommendations are made for improving their technical performance to meet the professed United Nations potable water supply goals.

The future impact of computers on water resources education is assessed in terms of the nature of the educational process (logical analysis, instruction, and invention), of the components of the water resources field (water cycle analysis and water cycle modification), and of the principal elements of computer technology of relevance to water resources (machines, programs and data bases, networks, work stations, field station, and robots). Advances in computer technology make it possible to envision, through education and research, the rethinking of the organization and operation of the water resource field, the enhancement of a global‐systemic view of water resources, the strengthening of socio‐technological analyses, the expansion of artificial intelligence approaches, and the creation of custom‐made computer chips for water resources (“hydrochips”).

Proper planning of water conveyance systems requires consideration of both environmental and engineering factors in the earliest phases of project evaluation. A method is presented for using environmental data directly in the preliminary selection of a pipeline or canal route. The environmental factors considered include land use; mineral, water, and ecological resources; and transportation networks. The method requires the study area to be divided by a rectangular grid into subareas or cells. A cumulative disturbance cost is calculated for each cell according to the features in that cell and subjective disturbance penalties. The possible routes are represented by a directed network with the length of each route segment corresponding to the average of the disturbance costs for the connected cells. The minimum‐impact route is determined by solving for the shortest path in the network using a mathematical algorithm. The method is demonstrated for a potential canal in southeast Texas.

In Iran the government under the Shah's regime nationalized the water resources of the country and legislated a detailed statute concerning the development, allocation, and use of this limited resource. This paper critically examines the Nationalization of Water Resources Act (NWRA) from the standpoint of promoting economic efficiency. A historical study of past water laws reveals a strong philosophical link with the concept of nationalization. The NWRA denounces the market mechanism and centralizes all aspects of development, allocation, and use of this resource. The analysis in this paper reveals that efficiency and optimality in the allocation and use of water cannot be attained through these laws. A review of the performance of a number of water agencies that were established prior to the NWRA shows that they are successful in gaining the advantage of economies of scale, internalization of external effects, and reduction of waste. Under these systems, the farmers have the ultimate discretion with regards to allocation, use, and transfer of water. Recommendations in this paper could be valuable to the current legislators who are engaged in the development of a new body of water laws.

Methods for determining the optimal design capacities and distribution management of water delivery systems in the presence of probabilistic supplies and known transportation losses are presented. A continuous distance model of the conveyance system, solved by calculus of variations, is used to expose and explain a variety of economic tradeoffs, capacity design patterns, and water distribution patterns that occur in economically optimal delivery systems. The results rely on optimality conditions developed in the paper. Supply variability and users' supply levels are shown to have important influences on the optimal solutions.

This paper develops methods for determining the optimal design capacities and distribution management of water delivery systems in the presence of probabilistic supplies and known transportation losses. A discrete distance model of the conveyance system is solved by using dynamic programming. In the method's development, important general economic interactions are detailed. The practical value of the model is demonstrated in an example for an aqueduct to serve four farming areas and one urban area. In the example, the method finds the optimal capacities and distribution patterns for the aqueducts, and the net expected benefits for the users for four management options being considered by the urban area. This provides the urban area with the information needed to compare the options.

In the design of hydraulic structures for flood control, it has become standard practice to employ the average return period of a flood as the design event. This study introduces an analogous index for the design of a water supply system: the average return period of a reservoir system failure, defined as the expected number of years until the first reservoir system failure. Here a failure is defined as a year in which the prespecified yield could not be delivered by a water supply system. The mean and variance of the time until the first reservoir system failure are derived, as are the mean and variance of the duration of a reservoir system failure for a simple Markov failure model. Other indices of the reliability of a water supply system are also introduced. The assumption that sequences of reservoir surplus and failures can be represented by a two‐state Markov chain is validated for the Pacific Northwest Hydroelectric Power System.