Showing papers on "Water supply published in 1986"

Why Are There So Few Transactions among Water Users

Abstract: Water to supply growing demands from agriculture, households, and industries in the arid West traditionally has been secured through water storage and conveyance projects. Economists have been warning for years that increasing scarcity and costs of unappropriated water supplies (e.g., Wollman) together with limited public budgets and the environmental costs of new projects would shift attention to nonstructural approaches, particularly to the market mechanism, to meet emerging needs. Change, however, appears to be slow. To some observers, for example Anderson, the number of recorded instances where water supply problems are solved by market-like transactions remains far too limited.

Evaluating health impact : water supply, sanitation, and hygiene education

Abstract: Meeting: International Workshop on Measuring the Health Impact of Water and Sanitation Programs, Nov. 1983, Cox's Bazaar, BD

Women and the Transport of Water

Abstract: List of Acronyms i-v Preface v I WOMEN AND THE TRANSPORT OF WATER A Background 1 B Why Improve Water Supplies? 3 C Transport and Development 5 D The Division of Labour 6 E The Consequences of Having to Carry Water 9 1 Health effects 9 2 Economic effects 10 3 Social effects 12 F Alternative Technologies 13 1 Carrying aids 14 2 Wheelbarrows and handcarts 17 3 Animal transport 18 4 Others 19 5 Introducing new technologies 21 II KENYA: THE PROBLEMS AND SOME SOLUTIONS A Water Supply in Kenya 23 B The Workload 25 C Carrying Methods 28 D Case Studies in Kenya 32 1 Kamajene Farmers' Centre 32 2 Action Aid - Kibwezi Region 34 3 Utooni Development Project 36 4 Discussion 39 E Donkeys in Development 42 III CONCLUSIONS A General Conclusions 44 B Conclusions on Kenya 44

Network model for decisionsupport in municipal raw water supply

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.

Basic environmental technology: Water supply, waste disposal, and pollution control

Abstract: Basic Concepts Hydraulics Hydrology Water Quality Water Pollution Drinking Water Purification Water Distribution Systems Sanitary Sewer Systems Stormwater Control Wastewater Treatment and Disposal Solid and Hazardous Waste Air and Noise Pollution Appendixes Index.

Evaluating Institutional Alternatives for Managing an Interrelated Stream-Aquifer System

Abstract: Farmers relying on the South Platte River in northeastern Colorado for irrigation water have been found to be adversely affected by pumping from a groundwater deposit associated with the river. A simulation model of the hydrologic‐legal‐farmer decision system is developed and employed to analyze several institutional alternatives for managing the system. The “augmentation plan” approach recently developed by the state was shown to yield highest net incomes under both normal water supply and drought scenarios while protecting the prior rights of river water users. Anticipated opportunity costs of ground water use are internalized into pumpers' decisions.

Allocation of Augmented Water Supply Under a Priority Water Rights System

Abstract: A generalized network flow model has been developed to simulate the allocation of additional water supplies in a river basin with observance of the prior appropriation doctrine of water rights and other legal requirements such as interstate compact agreements. The computer model, called MODSIMR, is capable of simulating complex river basin morphology while incorporating a relational data base management system for efficiently accessing prioritized water rights. Program MODSIMR is a generalized model designed to be applicable to a wide variety of river basins operating under an appropriative water rights system. As a demonstration of its usage, MODSIMR was applied to the Rio Grande Basin of Colorado, New Mexico, and Texas for predicting allocation and use of increased runoff from simulated silvicultural activities on the Rio Grande National Forest. Results indicate that under the current institutional framework, increased runoff would primarily be allocated to agricultural users in Colorado. Computer results also showed the potential value to Colorado of the Closed Basin Project in the San Luis Valley and the possibility of determining optimal pumping schemes for the Project using MODSIMR. Program MODSIMR will be useful in future economic studies to determine the benefits of the augmented water supply under various water use scenarios.

Piped water supply and intestinal parasitism in Zimbabwean schoolchildren

Abstract: The prevalence of intestinal parasitism in primary schoolchildren in three areas, communal (peasant farm) lands, commercial farms and urban townships, was assessed by examination of concentrated and stained stool specimens to determine the effect of water supply on intestinal parasitism. Piped water in communal lands was associated with decreased frequency of schistosomiasis and hymenolepiasis, but not with decreased frequency of protozoa. Schistosomiasis was very common in commercial farm labour communities, particularly on farms adjoining the local river, despite the availability of stored borehole water supplied through communal taps. The prevalence of intestinal parasitism in children from urban areas with municipal water supplied to taps in each household was similar to that of children in communal areas who obtained water from surface streams. The frequency of Giardia lamblia infection was higher in urban than in rural schoolchildren, and within communal areas was higher in children with access to protected borehole water. The provision of piped water was, therefore, not found to be associated with reduced prevalence of intestinal parasitism, though additional factors such as frequency of contact with infected water, the provision of ancillary improvements and the actual usage of available water supplies would need to be more closely assessed.

Potable Water for All: The Egyptian Experience with Rural Water Supply

Abstract: Egypt during 1952–1960 achieved a more rapid and proportionately larger improvement in potable water supply for its rural population than any other developing country. The way in which this was done laid the groundwork for later difficulties in maintenance and extension of services. Similar problems arose in the Fayoum project in 1953–1964. A program for basic village services initiated in 1979 applied some of the lessons learned in the earlierprogram, but raised new environmental issues. The early change in water service was not followed by striking reductions in prevalence of childhood disease.

Presence of Legionella in London's water supplies.

Abstract: Legionella occurs frequently (52 to 54%) in domestic water and cooling water inside commercial, industrial and health care buildings, and these types of water systems are now regarded as a normal habitat for Legionella. The factors that predispose a particular water system to colonization by these organisms are ill-defined, although it is fairly certain that biological and physicochemical environmental factors play an important role in allowing Legionella to multiply in the circulating water. It has been postulated that the organism may gain access to water systems inside buildings by one of three routes: contact with air through open points such as uncovered storage tanks or vents, ingress of soil or surface water during construction or repair, or intermittent seeding with organisms present in low numbers in the public water supply. Three studies in the USA have found Legionella in 0.4 to 8.8% of drinking-water samples, but these were not representative of the public supply network as a whole. The aim of this study was to determine, over a period of 1 year, the frequency of Legionella in London's drinking water--from the treatment plant through to the consumer's tap. To date, Legionella has not been isolated from raw river water entering London's treatment works or from treated water entering the distribution network. Sixty-two monitoring taps in buildings located in 21 supply areas have been sampled twice for Legionella; only 2 (2.4%) have proved positive during the autumn and winter of 1985/86. The strain found was L. pneumophila serotype 1, subgroup Olda, and the numbers ranged from 10(2) to 10(4)/l. Although the survey is incomplete, it is already clear that the public water supplies in London are not a source of strains of Legionella associated with disease.

Developing and Applying the Water Supply Simulation Model

Abstract: Passage of the Safe Drinking Water Act has intensified interest in problems related to water supply and water utility management. Analysis of the regulations to be promulgated under the act indicates that some water utilities, particularly small ones, may be adversely affected economically.1 An often-suggested option is that small systems combine with a larger system to form a regional water supply utility. It is assumed that the economies of scale associated with a regional water system would benefit the customers of small systems. A characteristic of many production and transportation problems is the trade-off between the cost of building and operating facilities to meet demands for a product and the cost of transportation.2 High transportation costs and low facility costs indicate decentralization; the reverse situation indicates a few large central facilities. These costs must be considered in planning, designing, constructing, and operating water supply systems. It is possible to separate the water supply system physically into two components: (1) the acquisition and treatment function, and (2) the delivery (transmission and distribution) system.3 Each of these components has a different cost function. The unit costs associated with treatment facilities are usually assumed to decrease as the quantity of service provided increases. The delivery system, however, is more directly affected by the characteristics of the area being served. The cost tradeoffs between the two components determine the cost of delivering water to any portion of the service area. Because few analytical instruments are available for study of the economics of water supply systems, the US Environmental Protection Agency's Drinking Water Supply Research Division initiated a program to develop techniques and methodologies to evaluate the economics of regional systems. This article describes the development of a simulation model designed to aid in such an evaluation. The model can also provide insights into other water-related economic issues, such as spatial pricing and costing, conservation policies, operating improvements versus increased capital expenditure, user class subsidization, and fire protection capacity. The model, called the Water Supply Simulation Model (WSSM), incorporates a series of submodels to describe the various economic, demographic, and hydraulic aspects of a water utility.

Guidelines for Planning Community Participation Activities in Water Supply and Sanitation Projects

Abstract: Guidelines for planning community participation activities in water supply & sanitation projects , Guidelines for planning community participation activities in water supply & sanitation projects , کتابخانه مرکزی دانشگاه علوم پزشکی تهران

A systematic approach to improve the planning, design and operation of surface water management systems : a case study

Abstract: From an agricultural point of view the most desired surface water level in areas with a shallow groundwater table is low during winter and high during the growing season Waterboards in the Netherlands try to fulfil this demand by applying different surface water levels in winter and summer Because weather conditions vary considerably from year to year, the most desired open water level should be varied too 'The manipulation of weirs by the Auterboards is mainly based on practical experience and is riot much different from year to year To obtain better founded rules for surface water manipulation, a study was carried out in a cut-over peat region of about 8000 ha For the surface water, the groundwater and the unsaturated soil water system in this area a simulation model was constructed that links these systems mutually and offers the possibility of computing consequences of manipulating open water levels for the water use by crops The model was calibrated with hydrological data collected in the area operational rules for setting weirs and inlet structures were established by comparing the effects of a number of possible rules on depth of groundwater tables and consequent water uptake by the crops for a number of meteorological years With the operational rules that gave the largest effects m water use by the crops management strategies involving water conservation and additional water supply capacities for sub-irrigation were simulated with the model The additional transpiration by the crops caused by these strategies were converted to extra yields so that an economical analysis of these strategies became possible With the aid of the results of this analysis also a demand function for water for the study area was derived Finally the possible application of the demand function in the water management policy at provincial level was outlined The results show that the proposed model offers good possibilities to forecast effects of water management strategies It can be used by a waterboard to decide upon changes in open water levels that are required in the course of the season because of weather conditions The weakest point in the model seems to be the lack of knowledge about the possible negative effects of waterlogging on transpiration by crops For the conditions prevailing in the study area, water conservation is economically very attractive Additional water supply to the area for sub-irrigation has a relatively low efficiency, but the economical analysis shows that investments in this strategy may pay off too

Migration to and from dry areas in Kenya.

Abstract: The factors affecting migration to and from the dry areas of Kenya are examined. The author notes that since the 1970s the dry areas have been affected by droughts disease and military conflicts. However at the same time they have changed from being areas of out-migration to areas of in-migration. (ANNOTATION)

An Integrated Surface and Groundwater Flow Model for the Design and Operation of Drainage Systems

Abstract: In The Netherlands dense channel systems are present for land drainage. In periods with a shortage of water these systems often serve to supply water for agricultural purposes as well. Because of the double function of these channels it is very important that they are maintained properly. Weed control, for instance, is necessary to prevent waterlogging or flooding in the case of high discharges. Maintenance costs are a heavy burden for the local water authorities. The frequency of maintenance activities is usually determined by a rule of thumb. This may result in too much maintenance. On the other hand the frequency of maintenance may be too small giving a greater danger for flood damage or insufficient water supply. The situation is even more complicated because water levels vary during the year. For a good water management the water level in winter is generally kept low to allow a quick drainage, whereas the level is raised in spring to conserve water for dry periods in summer or to make subsurface irrigation possible.

Minimizing the Cost of Coping with Droughts: Springfield, Illinois

Abstract: Past drought experiences show that the failure of water supply systems to meet demands during droughts can be reasonably described in terms of the tangible monetary expenditures and economic losses related to emergency actions. A framework is presented that allows planners of water supply systems and utility managers to formulate least-cost drought emergency plans, and to systematically examine the trade-off between the expected value of the long-term cost of coping with water supply deficits and the cost of the long-term water supply/conservation projects. The suitability of the framework as an analytical tool for water deficit planning is illustrated in a case study of the water supply system of Springfield, Illinois. The analysis shows that the optimal short-term programs for the mitigation of potential shortages of water during droughts consist of a combination of moderate demand and loss reduction measures coupled with intensive utilization of emergency water supply systems. However, the choice of demand reduction measures should involve a certain degree of discrimination among various user sectors in order to avoid substantial losses to the local economy.

Demand Irrigation Schedule Pilot Project: Sri Lanka

Abstract: Since 1981, the Sri Lanka Government has been testing a different approach to delivering irrigation water to its numerous small‐scale farmers. Instead of conventional open‐channel rotation irrigation with water controlled by government organizations, a 367‐acre (147‐ha) pilot project has put each farmer in control of his own water supply using a limited‐rate demand irrigation schedule. This system conjunctively utilizes sloping canals, on‐stream regulating reservoirs, automatic float‐controlled canal gates, level‐top canals, and buried concrete pipelines with float valves to maintain low pressure. Discussed are construction costs and materials, the four cropping seasons evaluated, and the advantages and disadvantages compared to conventional irrigation. Current data show that: an adequate and equitable water supply can be achieved and sustained; crop production can be increased from 8 to 20 bushels/acre (160 to 400 kg/ha); the potential exists for reducing water use below that of conventional irrigation; ...

Water leakage detection device

Abstract: PURPOSE:To detect water leakage by providing a heating device for heating water in a water pipe and a water temperature sensing elements at the inlet and outlet of the heating device at the halfway of the water supply pipe. CONSTITUTION:The water supply inlet 2 of a hot water supply unit 1 is connected to the water supply pipe 5 such as water pipe, and the heating device 7 is provided so as to cover a portion of the surface of the pipe 5 for heating the water in the water supply pipe 5 by a small power at all times. The water temperature sensing elements 6a, 6b can measure the water temperature in the pipe 5 and is provided to directly contact with the water in the pipe 5. The water temperature sensing elements 6a, 6b are separately mounted at the inlet and the outlet of a heating device 7 at equal distances from the center of the heating device 7. The detected water temperature is sent to a water temperature discriminating device 8 with a minute voltage. For example, in case of water leakage in the water supply unit 1 or in the piping, an extremely small flow is induced in the hot water supply pipe 5 resulting in movement of the water heated in the heating device 7 so that the elements 6a, 6b sense different water temperatures and the water leakage is informed by emitting the sound or the rays of light from the water leakage discriminating device 8.

Global Water Issues

Abstract: Five critical global water-related issues are discussed. First is the issue of climatic changes and drought. Unfortunately, the opportunities to construct major irrigation projects are very limited in arid Africa (the region of several catastrophic droughts) and their radius of influence is small. Practical solutions are a long way off. A second area is that of soil erosion and sedimentation. Engineers and scientists are making progress, but this is a relatively new area of research. Next, the world's outdated irrigation systems must be modernized. There is so little water remaining to exploit that cultivating new land is possible only through water savings by the existing users. In much of Asia, surface irrigation has an overall efficiency of about 30% compared to about 37% in the U.S. and 60% for well-managed systems. Pollution and water quality has been a concern in industrialized nations for many years. But developing nations are beginning to be worried about their drinking water. Irrigation is causing pollution from salinity. Groundwater pollutions from many sources is also becoming a problem worldwide. Finally, support for the International Drinking Water Supply and Sanitation Decade is urged, especially from developed nations such as the U.S., which have resources to offer other nations.

Urban Runoff Impacts on Receiving Waters

Abstract: Urban stormwater runoff contaminants affect the principal receiving water uses of: (1) public water supply, (2) recreation, (3) protection of aquatic life forms, (4) agricultural and industrial water supply, and (5) groundwater protection in diverse ways. Through exploration of impacts to aquatic ecosystems, the paradoxes and uncertainties of the urban runoff quality phenomenon become apparent. Key questions must be answered when assessing the impacts of urban runoff constituents on receiving water uses.

Pressurised water supply plant for water desalination

Abstract: The pressurised water supply plant is used for a water desalination plant which operates by the osmosis principle. In this case, salt water is pumped to a high pressure and a part thereof is branched off as fresh water via filter devices. The portion of the salt water not flowing through filter devices is fed to a water turbine for energy recovery. In order to be able to design pumps and turbines with optimal efficiencies, two pumps are provided of which the low-pressure pump (2) is driven by a motor (3) whereas the high-pressure pump (6), coupled to the turbine (13), forms a separate unit.

Drought contingency planning

Abstract: Simulation gaming has the potential to enhance the effectiveness of drought management planning. The Indianapolis water supply system is used to illustrate how. First, the probability of experiencing a severe drought in Indianapolis is examined using historical streamflow data. The effects of such a drought on the municipal water supply system are then analysed using a recently developed simulation model of the Indianapolis water system. Consideration is given to the water resource decision-making problems that might arise under drought conditions, along with a discussion of the benefits of employing simulation gaming in the analysis of these problems. A basic outline for the design of a drought management simulation exercise is presented.

Wastewater recycling and reuse.

Abstract: Currently, there is considerable interest in the potential health effects associated with the direct and indirect human consumption of reclaimed wastewaters. Indirect human consumption of wastewaters occurs when surface water, particularly rivers receiving wastewater discharges, are used for water supply. These surface sources, along with an increasing number of groundwater resources, are contaminated by the waste discharges from communities, industrial activities, agricultural and urban runoff, and storm water. Using these sources of supply, water treatment plants have produced water that is considered safe for human use, although these finished waters may contain low levels of organic chemicals which may be potentially harmful following long-term ingestion.