OPTIMIZATION MODELING OF A NEW FACILITY FOR THE CALIFORNIA STATE WATER PROJECT1

ABSTRACT: A non-linear optimization model is applied to the California State Water Project (SWP) and portions of the Central Valley Project (CVP). The model accounts for the major hydrologic, regulatory, and operational features of both projects. The model maximizes long-term SWP yields over a 70-year period, using a quarterly time step. The potential for increased yield associated with a proposed facility improvement is evaluated with the model. The proposed facility is an extension of the Folsom-South Canal, which would allow water to be conveyed from the American River below Folsom Reservoir into New Melones Reservoir on the Stanislaus River or into the California Aqueduct. Model results indicate that extension of the Folsom-South Canal has the potential to increase SWP yields by 13 percent.     

AN ANALYSIS OF WATER RESOURCES CONSTRAINTS ON POWER PLANT SITING IN THE MID-ATLANTIC STATES1

ABSTRACT: Expansion of the electrical generation system in the Pennsylvania-Jersey-Maryland power pool will impact, and be constrained by, inland water availability. Future interpretations of the Federal Water Pollution Control Act Amendments of 1972 regarding evaporative cooling towers for coastal power plants, offshore siting and energy centers, and the policies and public acceptability of low flow augmentation reservoirs are some of the issues examined in this paper using scenarios generated by the Brookhaven National Laboratory Regional Energy Facility Siting Model (REFS). REFS is a multicommodity, transshipment-location linear programming model used here to allocate power plants among counties in a power pool under a minimization of cost objectives. The solutions are sensitive to the water resources assumptions in the model. For the year 2000, the amount of low flow augmentation allowed in the region's river basins and whether off-shore siting becomes a reality are the two water resources related issues which most affect the scenarios. The results show that decisions regarding specific water problems can have region wide implications for water and nonwater related issues.     

COMPARISON OF STOCHASTIC AND DETERMINISTIC DYNAMIC PROGRAMMING FOR RESERVOIR OPERATING RULE GENERATION1

ABSTRACT: Two dynamic programming models — one deterministic and one stochastic — that may be used to generate reservoir operating rules are compared. The deterministic model (DPR) consists of an algorithm that cycles through three components: a dynamic program, a regression analysis, and a simulation. In this model, the correlation between the general operating rules, defined by the regression analysis and evaluated in the simulation, and the optimal deterministic operation defined by the dynamic program is increased through an iterative process. The stochastic dynamic program (SDP) describes streamflows with a discrete lag-one Markov process. To test the usefulness of both models in generating reservoir operating rules, real-time reservoir operation simulation models are constructed for three hydrologically different sites. The rules generated by DPR and SDP are then applied in the operation simulation model and their performance is evaluated. For the test cases, the DPR generated rules are more effective in the operation of medium to very large reservoirs and the SDP generated rules are more effective for the operation of small reservoirs.     

DYNAMIC PROGRAMMING FOR OPTIMUM CONJUNCTIVE USE1

The Las Vegas, Nevada area like most semi-arid basins, was developed through exploitation of available ground-water resources. Area growth in this large valley has occurred in a scattered and sporadic manner with development both in incorporated areas and within the County. As a result, today there exist five major water suppliers which are: a water district, three municipalities, and a large corporation, in addition to numerous small water companies and thousands of domestic wells. In the past 20 years the area has grown from a population of less than 50,000 to over 300,000 today. The bulk of the water demand for this growth has been met from the ground-water resource and as a result the basin is being severely mined. Current extractions are over three times the estimated annual replenishment. Rapidly declining water levels are increasing the costs of water and are creating water shortages during periods of peak demand. To meet both the current and anticipated water demands, the Southern Nevada Water Supply Project is being constructed to import additional water from nearby Lake Mead. Agriculture in the area is very limited, and primarily uses reclaimed waste water for irrigation. The chief water demands in the area are thus municipal and industrial, with the former predominating. This study was designed to determine how best the Las Vegas Valley Water District, supplier of 80 percent of the domestic water, might integrate the use of the existing ground water and anticipated imported surface water. Additionally the consequences of application of certain provisions in the Nevada Water Law were examined to determine their effects on the ground-water system and costs of water. To achieve these objectives, a dynamic programming technique was utilized. The problem as formulated consists of a single decision variable, single state variable dynamic programming algorithm evaluated over a fifty-year planning horizon at monthly intervals. Three alternative solutions, with different ground-water law constraints are evaluated. In all solutions certain basic operating rules regarding ground-water pumping distribution and use of surface-water systems are kept constant. The problem is considered as deterministic in all respects. Recharge to ground water is assumed to equal the estimated average annual replenishment evenly distributed over the year and additionally is not considered to be a function of average basin ground water potential. The only surface supply, Lake Mead, is considered to operate at near constant elevation and not be subject to shortage conditions. In light of the size of Lake Mead, the Colorado River flow and the size of Nevada's allotment, 300,000 ac ft, the latter assumption is reasonable. Demand for water is considered as a known function of time. Optimization of conjunctive use for the Water District is based on the objective function of minimizing water production costs. Costs of distributing water are considered to be constant regardless of source, and so are not included. Also, fixed costs of amortizing the pipeline project and well fields are not considered. Results of the study are presented as a series of policy traces under each of the three alternatives considered. These traces describe the ground-water basin response under optimal operating conditions, given an estimate as to the present worth of ground-water pumping rights, and prescribe monthly water-procurement schedules for the operation of the Water District.     

AN INTEGRATED APPROACH TO WATER RESOURCES DEVELOPMENT OF THE TEHRAN REGION IN IRAN1

ABSTRACT: In this paper, a system approach to water resources development in Tehran Metropolitan Area, with its complex system of water supply and demands, is discussed. Water resources in this region include water storage in the Lar, Latyan, and Karaj reservoirs, the Tehran aquifer, as well as water discharge in local rivers and in drainage channels (mainly supplied by urban runoff and wastewater). This study consists of three phases of long‐term water resources planning and management in the Tehran metropolitan area. In each phase, a different level of details among different components of the system is considered. In the first phase, optimal operating policies for Tehran reservoirs and a decision support system are developed. In the second phase, interactions between surface and ground water resources as well as surface runoffs and wastewater disposal in different subareas are investigated. The water table fluctuations as a result of implementing sewerage collection project was also simulated. In the last phase, long‐term scenarios for water resources and agricultural development in the Southern part of Tehran are defined, and the effects of each scenario on the quality and quantity of surface and ground water resources are studied.     

ENERGY AND WATER CONSERVATION STRATEGIES IN IRRIGATED AGRICULTURE1

ABSTRACT: Growers in California used several energy and water conservation strategies in response to the drought conditions of 1976 and 1977. The strategies included an increased use of ground water, in creased irrigation efficiencies, and shifts in cropping patterns. Drought-related losses to irrigated agriculture were minimized as a result of these modifications. Some future problems may have been created, however, by obtaining the needed water supplies for 1976–77. These problems include the effects of extensive water pumping on ground water reservoirs and ground subsidence. In addition, reduced water application by less frequent irrigation and changes in irrigation methods may affect the total salt balance for future years. Several conservation strategies that have some potential application in California were identified as: maintaining and augmenting surface water supply, increasing power use efficiencies, and improving irrigation efficiencies. Electricity savings associated with water conservation have been estimated as high as 25 percent. Specific near term actions suggested for facilitating conservation included: an expanded irrigation management system, efficient water deliveries, and a continued effort on the part of the individual growers to use resources during periods of normal rainfall as they were used under drought conditions.     

OPTIMIZATION OF INTERMITTENT PUMPING SCHEDULES FOR AQUIFER REMEDIATION USING A GENETIC ALGORITHM1

ABSTRACT: Using a genetic algorithm (GA), optimal intermittent pumping schedules were established to simulate pump‐and‐treat remediation of a contaminated aquifer with known hydraulic limitations and a water miscible contaminant, located within the Duke Forest in Durham, North Carolina. The objectives of the optimization model were to minimize total costs, minimize health risks, and maximize the amount of contaminant removed from the aquifer. Stochastic ground water and contaminant transport models were required to provide estimates of contaminant concentrations at pumping wells. Optimization model simulations defined a tradeoff curve between the pumping cost and the amount of contaminant extracted from the aquifer. For this specific aquifer/miscible contaminant combination, the model simulations indicated that pump‐and‐treat remediation using intermittent pumping schedules for each pumping well produced significant reductions in predicted contaminant concentrations and associated health risks at a reasonable cost, after a remediation time of two years.     

EMPHASIS ON DISTRIBUTION: STRATEGIES FOR SMALL SCALE WATER RESOURCES DEVELOPMENT IN THAILAND1

This paper discusses strategies for the development of water resources, emphasizing the delivery of reliable water supplies, for both domestic and production purposes, to every village and to every farmer. This necessitates a shift of emphasis from the construction of large storage reservoirs to the construction, operation, and maintenance of water distribution systems capable of reaching the largest number of farms, and a shift from projects that benefit the few, to projects that benefit the many. Water distribution in this context takes on three interrelated meanings: a geographical meaning, a technical meaning, and an economic meaning. The geographical meaning focuses on the spatial distribution of the recipient population as a key to identifying the proper distribution of water projects in physical space. The technical meaning relates to the physical distribution of water through canal systems to the farmers' fields. The economic meaning refers to the equitable distribution of benefits from water projects. The paper provides an illustration of the need for an emphasis on distribution, using the state of development of water resources in northeast Thailand as an example, with a proposed program for the further development of these resources. The northeast, the poorest region in the country, has been recognized by the Government of Thailand as a priority area for accelerated regional development efforts.     

OPTIMIZING THE PROBABILITIES OF WATER YIELD FOR THE RIDAURA AQUIFER (SPAIN)1

ABSTRACT: Aquifer pumping represents, in many geographical locations, an alternative and/or a complementary source of water to surface water supplies. Several Catalonian coastal towns in the northeastern corner of Spain are in this situation. Also, since pumped water is used to supply drinking water, the main purpose in managing these water resources is to supply, no matter the cost, the amount needed at every moment. In other words, the managers of these aquifers attempt to optimize firm water yield. If we think of these aquifers as underground reservoirs with fixed storage capacity, most of the techniques which are applied to surface reservoirs can be implemented. In this paper we use a Stochastic Dynamic Programming model to optimize the yield from the aquifer of the Ridaura River. The objective function in this model was chosen with the aim of maximizing the reliability of the target yields in each of four seasons.     

MODELING AND SENSITIVITY ANALYSIS FOR PLANNING DECISIONS IN WATER RESOURCES EXPANSION1

ABSTRACT. Individuals and organizations concerned with the expansion of the facilities of a river basin (such as a river basin authority) need to determine optimal strategies of operation and capital investment. They also need to examine the sensitivity of whatever planning decisions are contemplated. This paper extends the applicability of an algorithm that had been previously applied to the deterministic river-basin expansion problem to include the feature of a sensitivity analysis. The algorithm, containing a partial enumeration search technique and a network analysis code, gave a construction sequence of reservoirs, canals, and treatment plants, and an operating policy that maximized the present value of net earnings consistent with certain underlying assumptions. A river basin was chosen that had an existing configuration of unregulated streams and rivers, reservoirs, canals and treatment plants, and sites for future additional facilities. A series of representative synthetic flow sequences, future demand profiles, interest rates and reservoir costs that served as inputs to or parameters in the system were each perturbed by various factors (for a total of 24 cases). The sensitivity studies showed that the immediate planning decision of what facility to construct next was insensitive to variations in future demands and costs and independent of later decisions. Thus, decision-making was adaptive in the sense that by always making the optimal proximate decision, the management of the river basin is optimized.     

A SCREENING MODEL FOR WATER RESOURCES PLANNING1

ABSTRACT: Techniques of optimization and simulation are merged to select the most efficient arrangement of components for regional water resources development and management. Application is made to the Elkhorn River Basin in Nebraska. The Basin extends over 7,000 square miles and includes 184 proposed reservoirs. Structure sizes, locations and operating policies are selected for optimal plans based on economic efficiency and regional development. Results indicate that substantial savings in time and costs over conventional planning techniques are effected. Agreement between model output and agency design values was noted.     

CONJUNCTIVE USE OF SEA AND FRESH WATER RESOURCES: AN INTEGER PROGRAMMING APPROACH1

ABSTRACT Mathematical models are formulated for selection of water resources projects to meet the future additional water requirements of a given region at the minimum present worth cost. The projects available are surface water reservoirs and desalination plants. The modles are used for selecting both the development sequence of projects and their optimum sizes. Decisions with regard to planning time horizon and discount rates are made outside of the mathematical model. The algorithm used for solving these models is an integer programming routine using the implicit enumeration technique. Some computational results are presented for a hypothetical case.     

HYDROLOGIC ENGINEERING TECHNIQUES FOR REGIONAL WATER RESOURCES PLANNING1

The emphasis upon comprehensive regional water resources planning in the past decade has encouraged the hydrologic engineer to take advantage of improvements in technology to develop new hydrologic engineering techniques for use in regional planning studies. The new techniques are necessary because the traditional hydro-logic engineering techniques are not always consistent with the increased scope and diversified objectives of regional planning studies. The Hydrologic Engineering Center has been involved in aiding in the development of some of these new techniques as the result of studies that have been made in cooperation with other Corps of Engineers offices. Most of the new techniques being developed emphasize computational procedures developed specifically for use with electronic computers. Applications of new techniques range from framework studies to planning of day-to-day operation criteria. Studies recently completed or in progress include: (1) development of a regional flood control site screening plan for the North Atlantic Region study; (2) use of streamflow simulation for planning and operation of the Missouri River mainstem projects; (3) development of an operation plan for the Arkansas-White-Red Rivers Reservoir System; (4) standard project flood and flood frequency estimates for the Colorado River Basin Framework Study; and several other projects which are described in more detail in the following paragraphs. One of the initial efforts in regional analysis was the formulation of procedures for determining standard project flood estimates for southern California coastal streams using generalized criteria. Techniques were developed that were readily adaptable to the computer and which would determine representative unit hydrographs, losses and standard project precipitation for any location in the study area. The resulting standard project flood estimates were consistent with the accuracy required for framework studies; however, they could be refined easily for design studies. As a result of the recent drought in the Northeastern United States, a study was made to evaluate both present and future water supply reservoirs in that region. The study consisted of computerized studies of the hypothetical operation of a large number of reservoirs as a system. The reservoirs were on many different streams throughout the region and had varying constraints, depending upon the stream and the state in which the reservoir was located. Since only preliminary data was available on the proposed reservoirs, it was not possible to refine the studies to a large degree. However, the models of each system can be easily refined as more accurate design data become available. The development of a computer-aided screening procedure for use in evaluating several hundred potential reservoir sites for the Missouri River Basin Comprehensive Framework Study is a third example of regional analysis. The adopted procedures used available physical, hydrologic, and climatologic data in estimating reservoir storage requirements throughout the basin. Because the procedure is based upon the techniques often used in more refined studies, it is expected that the results of the screening study will be very useful in future planning and design work. Shortcomings of some of the traditional techniques have helped in the development of new techniques. For maximum usefulness the new techniques should: (1) be consistent with the scope, objectives, and requirements of the overall study; (2) use all available physical, hydrologic, and climatologic data without requiring extensive data which may not be available; (3) take full advantage of the capabilities of the computer and associated data processing systems; and (4) produce results which form a firm basis for future, more detailed, planning and design studies instead of being limited in usefulness largely to the study at hand.     

INSTITUTIONAL FRAMEWORK FOR REGIONAL COOPERATION IN THE DEVELOPMENT OF WATER SUPPLY AND DEMAND IN THE MIDDLE EAST1

ABSTRACT: Water is, and most likely will continue to be, one of the main concerns and potential causes of instability in the Middle East (ME). The contribution of the existing renewable water resources is limited and can not fulfill the long-term projected gap between water supply and demand for most of the countries in the ME. An integrated regional approach for fulfilling this gap was preferred. A regional institutional framework was proposed for the implementation of this integrated regional approach and consists of a regional water board operating through three units for technical, implementation, and management aspects of project and activities. An analysis of the regional water supply and demand development, the design and policy making of the proposed institution, technology and water markets, cooperation, actors and beneficiaries, finances, and expected obstacles and constraints to the establishment and sustainable operation of the proposed institution are included.     

OPTIMAL WATER USE AND SALINITY CONTROL FOR ENERGY - UPPER COLORADO RIVER BASIN1

ABSTRACT: The Upper Colorado River Basin contains appreciable amounts of undeveloped fuel resources. Large quantities of oil shale, coal, and uranium have attracted recent economic and commercial interests. Development of these resources and subsequent conversion to alternative energy forms require an adequate supply of water. Water use for large scale energy development will place increasing demands on an already overstressed allocation of Colorado River water. Present water quality is at a concentration where increased salinity will result in economic detriments to holders of downstream water rights. The salt and water exchange in mining, processing, and spent fuel disposal processes has been incorporated as part of a two-level minimum cost linear programming algorithm. Mathematical simulation results provide an optimal use of Upper Colorado River water for levels of energy output such that salinity concentrations are maintained below predetermined levels.     

ECONOMIC DESIGN OF CENTRAL WATER SUPPLY SYSTEMS FOR MEDIUM SIZED TOWNS1

ABSTRACT. Adequate and good-quality water supply for medium sized towns is costly when there are insufficient quantity and low quality of groundwater or surface water. In a central water supply system serving a number of towns, the economies of scale may permit a sufficient and good-quality supply at lesser rates. Such a system has the flexibility of supplying rural population through small service lines. The system may be an interbasin or intrabasin conveyance depending on the location of a suitable water source and the economics of the supply network. Seven cost elements are pertinent to the optimum or least-cost design of network consisting of pipelines and pumping stations. The relevant cost functions are based on the available data gathered from various sources. Water conveyance costs are calculated for various flow rates, pipeline diameters, flow variabilities, static heads, and interest rates, thus providing a measure of sensitivity of the conveyance cost to such variations. The economies of scale, the sensitivity of optimum unit conveyance costs, and variations in unit costs with change in cost functions are useful in making a feasibility study for a proposed conveyance system.     

TRANSIENT RESPONSE FUNCTIONS FOR CONJUNCTIVE WATER MANAGEMENT IN THE SNAKE RIVER PLAIN,IDAHO1

ABSTRACT: Increasing demands on western water are causing a mounting need for the conjunctive management of surface water and ground water resources. Under western water law, the senior water rights holder has priority over the junior water rights holder in times of water shortage. Water managers have been reluctant to conjunctively manage surface water and ground water resources because of the difficulty of quantification of the impacts to surface water resources from ground water stresses. Impacts from ground water use can take years to propagate through an aquifer system. Prediction of the degree of impact to surface water resources over time and the spatial distribution of impacts is very difficult. Response functions mathematically describe the relationship between a unit ground water stress applied at a specific location and stream depletion or aquifer water level change elsewhere in the system. Response functions can be used to help quantify the spatial and temporal impacts to surface water resources caused by ground water pumping. This paper describes the theory of response functions and presents an application of transient response functions in the Snake River Plain, Idaho. Transient response functions can be used to facilitate the conjunctive management of surface and ground water not only in the eastern Snake River Plain basin, but also in similar basins throughout the western United States.     

FACTUAL INPUTS FOR ALLOCATION DECISIONS CONCERNING SCARCE WATER RESOURCES1

ABSTRACT: Factual inputs which may be useful for completing first-order assessments to aid decision-making on the allocation of scarce water resources are compiled. Water needs of major manufacturing industry groups and of minerals industries show wide variations in several measures of water use intensity. The chemicals and allied products and primary metals industries dominate the total water intake and consumptive water use by manufacturing industries. Consumptive use per employee for the petroleum and coal products industry group is nearly 2.5 times higher than that for any other industry group. Estimates of the water requirements per unit energy output for energy-processing systems vary by as much as an order of magnitude. Agricultural water use is larger than that of any other industry but water use for irrigation is not expected to increase significantly by the year 2020. In California, the production of crop calories and proteins per unit of irrigation water applied may vary by more than an order of magnitude. Crops which offer larger monetary returns per acre are irrigated most frequently.     

RATES,RIGHTS, AND REGIONAL PLANNING IN THE METROPOLITAN WATER DISTRICT OF SOUTHERN CALIFORNIA1

ABSTRACT: The Metropolitan Water District of Southern California has for more than 70 years shaped the development of an immense urban region. The district's current strategic planning process therefore could have substantial effects on regional water planning and management. The rate restructuring phase of the planning process has produced a multiple component, cost of service based framework. This paper describes that framework as well as some criticisms that have been directed toward it. The rate restructuring was shaped, and for a while stalled, by old disputes among member agencies over rights to water supplied by Metropolitan. That controversy has diverted attention from the resource management implications of the rate structure. This paper presents an alternative future focused approach to regional integrated water resource planning for Southern California based on projections of current trends and anticipation of future events. This discussion raises the question of how regional integrated water resources planning of this sort may proceed, and what role Metropolitan will play in that process.