MUNICIPAL WATER SUPPLY RESTRICTIONS AS URBAN GROWTH CONSTRAINTS1

ABSTRACT: Municipal water supply restrictions and/or conservation policies are widely believed to affect urban growth, at least in Western states. An analysis of this issue, drawing upon a wide array of empirical water use research, casts doubt upon the presumed connection. Water availability seems likely to have little effect upon the amenities which draw newcomers to Western cities. It also seems to have little effect upon the locational decisions of industries which affect growth by creating new jobs. Consequently, there is little reason to oppose municipal water restrictions as prejudicial to urban growth or to favor such restrictions in the hope of constraining growth.     

THE IMPACT OF WATER QUALITY OBJECTIVES ON URBAN WATER SUPPLY PLANNING1

ABSTRACT: Optimal policies for supplying rapidly expanding urban centers with additional water supplies are shown to be dependent on water quality goals for the urban effluent. As effluents are required to meet increasingly stringent standards, the unit costs associated with adding capacity to existing wastewater treatment systems to renovate some waters for reuse are shown to substantially decrease. A nonlinear elimination algorithm is developed to delineate optimal policies. A model employing the technique was applied to the wastewater treatment system of a typical urban system and the water quality objectives varied. A comparison of costs with and without various levels of reuse were made and unit costs of reused water under these conditions determined.     

A LINEAR ANALYSIS OF AN URBAN WATER SUPPLY SYSTEM1

The use of linear programming as a planning tool for determining the optimal long-range development of an urban water supply system was explored. A stochastic trace of water demand was synthesized and used as an input to the model. This permitted evaluating the feasibility of imposing demand restrictions as an effective cost reduction mechanism. The City of Lincoln, Nebraska, was used as the urban model. The fundamental problem was to allocate limited water supplies from several sources to an urban load center to minimize costs and comply with system constraints. The study period covered twenty years, and findings indicate the planning direction for stage development during this period. Sensitivity analyses were performed on cost coefficients and demands. Thirteen sources were included in the initial computations. Conclusions were that linear programming and generated demand traces are useful tools for both short- and long-term urban water supply planning. Lowering peak demands results in long-range development of fewer sources of supply and more economic and efficient use of the supplies developed.     

EFFICIENT MANAGEMENT POLICIES FOR URBAN WATER SUPPLY1

ABSTRACT .This paper attempts to spell out the difficult conditions faced by urban water supply managers in achieving overall efficiency. Based upon these conditions, and changes that are likely in the next decade, it then tries to suggest strategies that would lead to even higher levels of efficiency in the future. A blending of political and economic concepts is used to make what is hoped to be a realistic analysis. What do we mean by “efficient”? The usual welfare economics definition is attainable only under a very special and highly unrealistic set of institutional arrangements. As soon as we delegate responsibility to a specialized agency we provide the opportunity, indeed we make it imperative that, in a social sense, a sub-optimization will take place. From the specifics of the indictment of this sub-optimization we can learn something about the opportunities for more efficient management in the future. In general there is an under-exploitation of multiple-function, multiple-objective opportunities. The pressures for sub-optimization hinge very directly on the sources of support and opposition to the water supply agency. A change requires the creation of a broader political base. The search for regional solutions is largely a political problem, and probably the development of flexible, responsive regional agency, so long sought, is still the answer.     

A PROCEDURE FOR ASSESSING WATER RESOURCES FOR URBAN PLANNING1

A matrix has been developed to guide the assessment of urban water resources. The matrix provides a means for determining the relative importance of water-related problems, and for identifying the data needed to evaluate these problems for the purpose of urban planning. The matrix columns list nine categories of potential water-related urban problems. The rows list 51 categories of data inputs which may be needed to evaluate the potential problems. The inputs include standard types of basic hydrologic data, information based on analysis and interpretation of these data, and information on the interfacing factors of climate, land, and culture. A system is described for ranking the relative importance of the problem categories and data inputs on a numerical scale of 0 to 3. From this, an index is derived that evaluates the relative importance of each input item to an overall program for water resource assessment. From the completed matrix the hydrologist can determine the availability of data to meet the identified requirements. Judgement can then be made as to priorities on work elements to provide the planner with maximum information in minimum time. The matrix also provides a basis for the development of programs and their funding in order to overcome critical data deficiencies.     

REGIONAL WATER SUPPLY PLANNING BY INTERACTIVE SYSTEMS ANALYSIS1

Abstract: This paper describes an interactive data and model generator that is intended to bridge the gap between the water resource enginner and planner and the mathematical progrmming systems approach to regional water supply planning. The optimization objective is to minimize total annual cost with respect to capital investment and operation and maintenance costs. The matrix generator formulates the necessary hydrologic, demographic and programming problem for system optimization. The interactive program guides the user through the input and optimization segments, totally eliminates the chore of manually structuring the model matrix aides in eliminating errors, and allows use by planners without skill in mathematical programming.     

INTEGRATED PLANNING OF RURAL WATER SUPPLY AND SANITATION1

ABSTRACT: Development schemes to improve the health of the rural populace through prevention of the transmission of communicable diseases should be considered in the context of some kind of “Sanitation Package” to ensure effectiveness. The general practice of concentrating resources on limited objectives, like water quality improvement, is shown to be less effective than allocating the same resources to multi-objectives defined in the Sanitation package. Systems Dynamic Modeling based on the DYNAMO II language, is presented as a capable tool for sanitation systems planning.     

SEWER AND WATER PRICING AND INVESTMENT POLICIES TO IMPLEMENT URBAN GROWTH POLICY1

ABSTRACT. The article proposes the use of certain water and sewer extension pricing and investment policies. Such policies would complement an urban growth policy designed to guide the location and timing of growth in urbanizing areas. Proposed pricing policies are based upon marginal cost principles. The types of pricing policies discussed include benefit assessments, connection fees, and user charges. Proposed investment policies deal with the division of financing responsiblities between the public and private sectors. Discussion of each proposal explains the economic influence of the proposed policies upon key decision makers in the land development process. The application of proposed pricing and investment policies in the case study communities is mixed. In Knoxville, Tennessee, where pricing and investment policies reflect the proposed policies, no urban growth policy exists. In Lexington, Kentucky, mixed pricing and investment policies do not complement what is a relatively good urban growth policy. In Greensboro, North Carolina, reasonably effective pricing and investment policies complement other policies which provide some guidance to the urban growth pattern. It is hoped that the article will increase the recognition of utility pricing and investment policies as one means of implementing urban growth policy.     

CONSERVATIONAL WATER PRICING FOR INCREASED WATER SUPPLY BENEFITS1

ABSTRACT: A study was undertaken to see if benefits from water supply could be increased by utilizing price-usage information in reservoir design studies. Three pricing policies were examined. The first policy assumed no price-use relationship, and quantity demanded was based on existing community usage with a low water rate. The price of water was set to recover system costs. A price-use relationship was assumed in the second policy and the water rate was constant. The price of water was determined from the associated system which provided maximum expected net benefits. The third policy assumed the price-use relationship and the price charged for water during each billing period was a non-linear function of storage which increased as the amount of water in storage at the beginning of the period decreased. It was found that the use of the conservation pricing policies substantially reduced storage requirements while providing demonstrable net benefits to the community and a large average supply. The conservation pricing policies substantially lowered the average price paid for water. The effect of uncertainty in consumer response to changes in price was studied by using a probabilistic price-use relationship. This uncertainty did not significantly reduce the effectiveness of the conservation policy. It was concluded that demand management by the use of a proper pricing policy could significantly increase net water supply benefits to a community.     

COST EFFECTIVE OPERATION OF URBAN WATER SUPPLY SYSTEM USING DYNAMIC PROGRAMMING1

ABSTRACT: Efficient operation of a city water supply system is an important goal of all municipalities. Efficient operation should result in minimum operation cost through reduction in total energy use and/ or reduction in on-peak energy consumption. An optimization model was designed for operating the water supply systems of cities using groundwater. The Newton-Raphson pipe network was used for network analysis and a dynamic programming optimization algorithm was used for determining a schedule for pump operation in the pipe network system. The model is most suitable for use in small cities with up to 45,000 in population, but with large-scale disintegration techniques may also be used for larger cities. The savings in operation costs are a function of energy cost and energy use pattern and water use pattern in the area.     

MAPS - A PLANNING TOOL FOR CORPS OF ENGINEERS REGIONAL WATER SUPPLY STUDIES1

ABSTRACT: A computer program (MAPS - Methodology for Areawide Planning Studies) has been developed by the U.S. Army Corps of Engineers, Waterways Experiment Station to assist planners in producing a comprehensive array of alternatives without sacrificing the detail and accuracy of the analyses. MAPS is a set of computer based models which can be used to simulate the water resource alternatives and to develop planning level design and cost estimates. Two application examples are discussed. The Salinas-Monterey (California) Urban Study sought to identify and determine cost of combinations of water source, transmission, and treatment to meet an array of water needs in future years. The Nashville (Tennessee) Urban Study had similar objectives but the output was prepared on a service area basis for more than 40 such units. Using MAPS it was possible to prepare planning level design and cost estimates for a very large number of alternatives.     

PLANNING LEVEL ESTIMATES OF THE VALUE OF RESERVOIRS FOR WATER SUPPLY AND FLOW AUGMENTATION IN NEW HAMPSHIRE1

: In general, the choice among reservoirs for water supply or flow augmentation is a multiobjective problem. Choices are based in part on the yield available from water supply reservoirs or, in the case of flow augmentation reservoirs, on the increase in low flows at downstream locations. Detailed estimates of these effects may be too costly for basin planning purposes. Thus this paper presents methods for rapid estimation of those quantities for New Hampshire. For water supply reservoirs, a composite empirical relation between Y95 (the draft available 95 percent of the time) and storage ratio, S*, is developed from previous studies in the region. For flow augmentation reservoirs, empirical relations between S* and degree of regulation, R*, are applied to each upstream regulating reservoir. Values of regulation arc then summed and divided by the mean flow at the downstream reach of interest. This parameter, (ΓR)*, is then related to increase in flow available 95 percent of the time by an empirical relation.     

A DYNAMIC MODEL FOR WATER AND RELATED LAND RESOURCE PLANNING1

ABSTRACT. Planning an optimal system of activities for generating economic goods and services within an existing natural resource capacity is a difficult problem to solve. A mathematical programming model with the capacity to check multiple resource demand and supply compatibility over many time periods was developed for the solution to this type of problem. The characteristics of natural resource supply and the demand of activities were utilized to reduce the number of time periods and to minimize the loss of the dynamic reality of the problem. Reduction in the number of time periods extended the capability of the model to the solution of complex resource planning problems without oversimplification.     

WATER CONSERVATION METHODS IN URBAN LANDSCAPE IRRIGATION: AN EXPLORATORY OVERVIEW1

ABSTRACT: The increasing use of irrigation for urban landscapes is causing new demands for efficient watering systems. Conservation techniques for irrigated agricultural fields cannot be applied to urban landscapes without amendment. This paper attempts to review methods of urban landscape water conservation in the context of the diversity and complexity of urban landscapes and the demands upon them for quality of the urban environment. A development's initial site layout and planting design fundamentally determine how much irrigation water will be required; the complexity and creativity inherent in urban design open a number of specific possibilities for reducing water demand. Irrigation hardware is then designed to deliver the required volume of water to the specified landscape efficiently by implementing a number of physical and operational principles. Maintenance of the finished development involves monitoring results and making adjustments as the plantings grow and develop. The potential for conserving urban irrigation water is large. Effective conservation need not compromise other qualities of the urban environment such as aesthetics, screening, or shade. Urban design can address both the kinds of landscapes people need, and minimal consumption of irrigation water.     

ACHIEVING URBAN WATER CONSERVATION1

ABSTRACT: Increasing costs and competition for water have resulted in pressure to manage urban water demand through conservation programs. Metering, pricing, devices, restrictions, building code changes, and horticultural practices have all been effective in reducing average residential water use. Some conservation means are specifically aimed at reducing peak demands but these usually reduce average usage as well. Combined programs of conservation can be expected to reduce urban demand by as much as 25–30 percent over the long term. Restrictions can reduce water usage on the short term even further. The success of conservation programs is as dependent on the effectiveness of public education and information dissemination as on the conservation practices themselves.     

NETWORK MODEL FOR DECISIONSUPPORT IN MUNICIPAL RAW WATER SUPPLY1

ABSTRACT: A water supply network optimization model called MODSIM3 is presented as a decision-support tool for aiding city staff in determining how best to utilize and exchange existing and potential water supplies with other users in a river basin. The model is applied to the City of Fort Collins, Colorado, water supply system as a means of determining optimum ways the City can utilize direct flow rights, storage rights, and exchangeable waters from various sources. Results clearly confirm both the benefits of the use of exchanges and the value of MODSIM3 as a water supply planning and management tool.     

INCOMMENSURABLES AND TRADEOFFS IN WATER RESOURCES PLANNING1

ABSTRACT: Society has many objectives, many of which are not commensurable. This incommensurability problem is generally referred to as the multiple objective problem and leads to the notion of tradeoffs. Various approaches to calculating tradeoffs in water resource development have been advocated by several authors. Many have made errors in the context of the conceptural model presented in this paper. It is argued the correct framework for tradeoff analysis is the neoclassical economic model. The relevant tradeoffs, then, are really price ratios. These, in turn, must be calculated in such a manner as to allow comparison of product mixes where the expenditure on resources is the same. This is where several authors have erred. An empirical example which illustrates the correct application of the model is presented.     

WATER SUPPLY AND WASTEWATER DISPOSAL IN RURAL AREAS OF INDIA1

ABSTRACT: Piped water supply and sewerage have been taken almost for granted in the developed countries. However, most people in the United States have little knowledge of the condition of public health amenities in the developing countries. The paper reviews the importance, background and current status of water and wastewater facilities in India. The relative situation in urban and rural areas, conventional practices in environmental hygiene, the programs for improvement and the problems involved with possible solutions are given. The case history of a town is also included for illustrative purposes.     

TEMPORARY WATER TRANSFERS FOR DRY-YEAR WATER SUPPLY1

ABSTRACT: Temporary transfers of water for dry year water supply are analyzed for cost and operational feasibility. The temporary transfer is implemented as part of a water rights option agreement (WROA) between a lesson and a lessee. First, engineering analysis determines the technical feasibility and operations plan under the Colorado doctrine of prior appropriation. The cost of the WROA to a water utility is estimated. Other considerations in the agreement are discussed. The WROA is compared to other dry-year supply alternatives using a water system simulation model to obtain expected cost and operational performance characteristics.     

SOCIAL WELL-BEING AND WATER RESOURCES PLANNING1

ABSTRACT: For many years, Federal water resources projects have been subjected to benefit-cost analysis to establish their economic feasibility. Several years ago social well-being was added as a consideration. This paper discusses the state-of-the-art in analyzing and evaluating aspects of social well-being. It stresses current short-falls and advocates a direction for further efforts.