NEW HAMPSHIRE WATER SYSTEMS: ENVIRONMENTAL AND OWNERSHIP CONSIDERATIONS1

An econometric model was developed to measure the influence of several environmentally oriented variables and an ownership variable upon the average total residential water costs for New Hampshire water systems. The implementation of leak detection programs, localized institutional rules and regulations, and hazardous waste inspection programs were statistically significant in influencing residential water costs. The existence of a water conservation program did not statistically influence these per unit costs. Water systems that were privately owned resulted in per unit costs that were higher relative to firms that were publicly owned.     

COST BEHAVIOR AND WATER SYSTEMS1

ABSTRACT: Several factors theoretically affect the cost behavior of water systems. These factors include scale, consumer density, and per capita usage. This analysis examines the several possible influences on the unit costs of water service. The statistical analyses indicate that among the factors of scale, per capita use, and consumer density, only the first two factors are important influences on water system costs. Water consumers appear to benefit from being served by large systems and being located in service areas characterized by relatively high per capita consumption. There is little statistical evidence indicating that more dense areas can be provided water service at lower costs than less dense areas.     

AN ASSESSMENT OF WATER UTILITY INFORMATION SYSTEMS AND THEIR USE OF COMPUTERS1

To provide an overview of water utility information systems and the extent of computer use, a direct mail survey of all water utilities serving populations of 2,000 or more in the tri-state area - Ohio, Indiana, and Kentucky - was conducted. The following was determined: 1) utility profile information, e.g., public/private ownership, age, number of accounts, etc.; 2) an assessment of the degree of computerization presently in place to perform various functions; and 3) an assessment of any plans that the utilities may have for future computerization. To analyze the data, an index of computerization was defined as the number of departments or major activity areas of each utility that presently have some computerization. The relationship between the degree of computerization (measured by this index) and a utility's profile in terms of population served, annual revenue generated, and the number of customer accounts is discussed for each state in the survey. Discriminant analysis revealed strong significant differences between utilities that plan to use computers and those that do not. The differences were identified by the authors. Survey results revealed a rather limited use of computers in the tri-state area. Enormous potential exists in small and medium sized utilities for computerization to improve operational efficiency.     

WATER MARKETS AND DECENTRALIZED WATER RESOURCES MANAGEMENT: INTERNATIONAL PROBLEMS AND OPPORTUNITIES1

ABSTRACT: Because of its importance and the perceived inability of private sector sources to meet water demands, many countries have depended on the public sector to provide water services for their populations. Yet this has resulted in many inefficient public water projects and in inadequate supplies of good quality and reliable water. Decentralization of water management, including the use of water markets, cannot solve all of these water problems, but it can improve the efficiency of water allocation. When given adequate responsibility and authority, water user associations have effectively taken over water management activities at a savings to tax payers. Moreover, water markets add the potential benefit of improving water efficiency within a sector as well as providing a mechanism for reallocating water among sectors. The key question involves developing innovative mechanisms for reducing the transaction costs of organizing water users and of making water trades. Water rights need to be established which are recorded, tradable, enforceable, and separate from land if markets are to operate effectively. Also, institutions are needed that effectively resolve conflicts over water rights, including third party impacts and water quality concerns.     

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.     

APPLICATION OF A SINGLE RESERVOIR OPERATION POLICY TO A RAIN WATER CISTERN SYSTEM1

The operation policy for a single reservoir is applied to a rain water cistern system because the functions of a cistern are similar to a simple single reservoir. Since the cistern is a closed system, water loss is negligible. In this study, a dynamic programming analysis has been made to study the effects of the probable weekly rainfall and the water storage in the cistern towards the water consumption policy. The result of this study indicates that the water consumption rate should be adjusted into a lower rate when the water storage in the cistern is low and/or when the expected probable weekly rainfall is low if the owner of the cistern does not want to risk the chance of an empty cistern. The demand for a reliable method for forecasting weekly rainfall is evident in this study.     

COST REDUCTIONS DUE TO SEASONAL VARIATION IN MUNICIPAL WASTE WATER TREATMENT LEVELS1

ABSTRACT: Varying treatment levels to meet seasonal variation in assimilative capacity of streams can reduce total costs of treatment. A mathematical model of a Pennsylvania stream based on a theoretically sound approximation of the physical relationships underlying the distribution of DO in a river system was used to determine discharge constraints for an economic optimization model which produced estimates of sewage treatment cost savings. Increasing the number of flow periods during the year enhances cost reducing opportunities even when land application processes are considered. Also, the least cost treatment process for year around operation may not be the least costly under multiple flow period management.     

INPUT-OUTPUT AND BENEFIT-COST ANALYSIS FOR WATER RESOURCE DEVELOPMENT PROJECTS1

ABSTRACT: The proper use of input-output for estimating regional benefits and costs is described for instances where project outputs go to final or intermediate demand. How that estimation is affected by the method used to value the primary project benefits and by the sector content of the input-output model compared to the primary sector affected are discussed as are points of terminological confusion between the two methods.     

HOUSEHOLD WATER USE: TECHNOLOGICAL SHIFTS AND CONSERVATION IMPLICATIONS1

ABSTRACT: A study was undertaken to determine the effect of water intensive appliances or activities on household water consumption. Activities included in the study were use of the washing machine, dishwasher, swimming pool, and lawn watering. In the majority of cases these activities increased per capita consumption and were statistically significant. Households included in the study were not familiar with water saving devices available in the retail market. Even if tehse appliances were purchased, private economic benefits to the household would be low due to the inexpensive water charges levied. However, aggregate community benefits could be large if new well drilling cost or increase in storage facilities could be avoided. In order to avoid these increased costs, regulation or subsidy programs may be the most efficient policy alternatives available to the communities. Subsidies and regulation could potentially decrease water use and offer alternatives to increasing the water supply.     

EFFLUENT FEES,AN ALTERNATIVE SYSTEM FOR ACHIEVING WATER QUALITY: A CASE STUDY1

This paper reports the findings of a case study of the relative costs of a uniform standards system and an effluent fee system of water quality control. A 30-mile stretch of the Black Warrior River in Alabama is considered. The analysis demonstrates that the dischargers could reduce total pollution abatement costs by 33 percent under the suggested effluent fee system.     

COLIFORMS AND WATER QUALITY: USE OF DATA IN PROJECT DESIGN AND OPERATION1

ABSTRACT: Knowledge of coliform transport and disappearance may provide information for project design and operation that minimizes potential water quality problems such as the violation of body contact recreation standards. Storm events were sampled in the Caddo River above DeGray Reservoir, Arkansas, and then tracked through the reservoir using the increased turbidity associated with the storm flows. Fecal coliforms were sampled both in the river and throughout the water column in the reservoir. In general, increased fecal coliform concentrations were closely associated with the increased turbidity resulting from the storm flows. This association existed for all three types of turbidity plume movement - overflow, interflow, and underflow. As the turbidity plume moved down the reservoir, fecal coliform concentrations decreased due to die-off, settling, and dilution. With several assumptions, it is possible to use this information to assist in locating recreational sites in a reservoir or to anticipate possible body contact standard violations at existing recreation sites.     

MUNICIPAL WATER CONSERVATION ALTERNATIVES1

ABSTRACT: The municipal water conservation options available to meet the goals of a national water conservation policy are evaluated. Water conservation with water conservation devices is shown to offer many significant advantages over education and pricing and metering as a method of accomplishing water conservation goals. Current constraints on the use of water conservation devices are outlined, and their elimination is suggested if the nation's water conservation goals are to be met.     

IRRIGATION WATER DELIVERY SYSTEM OPERATION VIA AGGREGATE STATE DYNAMIC PROGRAMMING1

ABSTRACT: A modified dynamic programming (DP) approach that is called aggregate state dynamic programming (ASDP) is presented to optimally operate irrigation water delivery systems. ASDP can be applied to multiple reservoir systems without encountering dimensionality problems. In addition, the random nature of water supply and consumptive crop demands can be incorporated into the technique. A case study is presented to display the application of ASDP. Using a sum-of-squared shortages objective, ASDP out performs a traditional separation technique and approaches the theoretical (ideal) optimum. Problem settings that are conducive to the use of ASDP and limitations of the technique are presented.     

MULTIPURPOSE OPERATION STUDIES OF A CANAL-LAKE-RIVER SYSTEM-OSWEGO RIVER SYSTEM,NEW YORK1

Use of systems analysis techniques for setting up flow regulation rules for the Oswego River System, a canal-river system with eight lakes, was examined. Two sets of lake regulation rules were proposed: the rule curve for each lake, and the lake-use priority curves for all the lakes. The former specifies balanced allocation of the storage in lakes to conservation pools and flood control pools and, the latter determines lakes releases depending upon the type of operation, the time of the year, and systems objectives. A generalized mathematical representation of the complex, multipurpose, multilake river systems operation is described. With appropriate measures of effectiveness and details of analysis, the problem was then solved with simulation and optimization. Use of the results in assisting basin plan formulation is also discussed.     

WATER RIGHTS,EMINENT DOMAIN,AND THE PUBLIC TRUST1

ABSTRACT: Faced with the necessity of meeting growing municipal water requirements in areas where available supplies are completely allocated, numerous cities throughout the West are turning to their eminent domain powers to affect a reallocation of water from less preferred uses to municipal uses, thus bringing about a sharp conflict with agricultural interests. As a basis for discussing these eminent domain powers, this paper begins with a brief review of the development of property rights. The existence of both private and public (social) rights in the “bundle of rights” is noted. In recent years the Public Trust Doctrine has been used to limit private rights in property, and to protect and strengthen social rights. A case study which focuses on a conflict between individual and social interests in water rights is discussed. This case involves the City of Thorton, Colorado which initiated municipal condemnation proceedings to acquire the water rights and structures of two nearby irrigation companies. The case represents an attempt to incorporate the spirit of the Public Trust Doctrine into legislation which sets forth procedures for resolution of similar water rights conflicts that will inevitably become more numerous throughout the West in the future.     

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.     

FORECAST UNCERTAINTY IN WATER SUPPLY RESERVOIR OPERATION1

ABSTRACT: This research investigates the benefits of forecasting in water supply systems. Questions relating operational losses to forecast period and accuracy are addressed. Some simple available forecasting techniques are assessed for their accuracy and applicability. These issues are addressed through the use of a simulation model of the Cedar and South Fork Tolt Rivers, where the system is modeled as a single purpose reservoir supplying municipal and industrial water to the Seattle metropolitan area. The following conclusions were made for this system: (1) reservoir operation deteriorates markedly with the loss of forecast accuracy; (2) the optimal length of forecasting period is five months; (3) reservoir operation may be improved by as much as 88 percent if perfect predictive abilities are available; (4) the mean of the historic data is not recommended to predict future flows because Markov methods are always superior; and (5) lag-one autoregressive Markov schemes exhibit about a 9 percent improvement in operation over no forecasting.     

AN EVALUATION OF WEEKLY AND MONTHLY TIME SERIES FORECASTS OF MUNICIPAL WATER USE1

ABSTRACT: A cascade model for forecasting municipal water use one week or one month ahead, conditioned on rainfall estimates, is presented and evaluated. The model comprises four components: long term trend, seasonal cycle, autocorrelation and correlation with rainfall. The increased forecast accuracy obtained by the addition of each component is evaluated. The City of Deerfield Beach, Florida, is used as the application example with the calibration period from 1976–1980 and the forecast period the drought year of 1981. Forecast accuracy is measured by the average absolute relative error (AARE, the average absolute value of the difference between actual and forecasted use, divided by the actual use). A benchmark forecast is calculated by assuming that water use for a given week or month in 1981 is the same as the average for the corresponding period from 1976 to 1980. This method produces an AARE of 14.6 percent for one step ahead forecasts of monthly data and 15.8 percent for weekly data. A cascade model using trend, seasonality and autocorrelation produces forecasts with AARE of about 12 percent for both monthly and weekly data while adding a linear relationship of water use and rainfall reduces the AARE to 8 percent in both cases if it is assumed that rainfall is known during the forecast period. Simple rainfall predictions do not increase the forecast accuracy for water use so the major utility of relating water use and rainfall lies in forecasting various possible water use sequences conditioned on sequences of historical rainfall data.     

NEW ZEALAND'S NATIONAL WATER QUALITY MONITORING NETWORK - DESIGN AND FIRST YEAR'S OPERATION1

ABSTRACT: The design and implementation of a national surface water quality monitoring network for New Zealand are described. Some of the lessons learned from the first year of operation are also addressed. Underpinning the design, and specified in advance, are the goal and objectives, the data quality assurance system, and the mechanism for data interpretation and reporting. Because of the difficulties associated with the use of a multitude of different agencies, only one agency is involved in field work and one laboratory undertakes the analysis. Staff training has been given a high priority. The network has been designed to give good trend detectability for regular sampling over a 5–10 year period.     

MUNICIPAL AND INDUSTRIAL WATER SUPPLY IN CIUDAD JUAREZ,MEXICO1

Rapid industrialization and population growth in the north Mexican desert city of Ciudad Juarez are placing a serious strain on the city's municipal water resources. Water deliveries and service area have more than doubled over the past decade, and plans for additional expansion are presently being implemented. This expansion is already contributing to water table declines and salinity increases in the Mexican portion of the Heuco Bolson, the sole source of water for the city. Continued mining of the limited fresh water reserves should produce serious water supply problems in the near future. New estimates of future water consumption incorporated into a digital aquifer simulation model indicate that these problems may show up much sooner than was anticipated in previous investigations. The results of this study point to the need to accelerate the gathering of basic data on alternative water resources. The problems faced by Cd. Juarez are illustrative of the kinds of difficulties likely to confront other rapidly developing cities of the arid zone.