Showing papers on "Water scarcity published in 1990"

Rapid Population Growth and Water Scarcity: The Predicament of Tomorrow's Africa

Abstract: The current set of population stabilization projections are based on rates of birth death and migration. These projections ignore economic natural resource and environmental constraints. These projections indicate that Africas population will stabilize at 4 times its current level. None of these projections assume that population may be resource limited to some degree. Africa is the poorest part of the world in terms of annual rainfall which translates into food because crops need it to grow. A significant part of Africa lies in the zone where there is an arid part of the year and often suffers from drought. Thus there is a high risk of crop failure. This is why African leaders are working hard to attain food self-sufficiency. The implications of water scarcity for living conditions especially food production are quite serious. As the population grows the per capita consumption will drop if the supply is static. However development requires water for many purposes other than food production. Industry and settlement both require a large portion of water. This leaves less and less water to feed more and more people. The net result is that per capita consumption will increase along with development yet in the region the amount of available water is low. Thus by the year 2025 1.1 billion or 66.6% of Africas population will be living with severe water scarcity. Population growth is the main problem slowing semi-arid development because such development requires an increase in per capita water consumption. But Africa does not have the water it needs to develop thus it has been said that the best thing developed nations can do is to stabilize world food prices. This would leave Africa with a window of opportunity in which they could divert more of their water to development. The levels of awareness among planners and political leaders is too low and must be raised. An understanding of the interconnected nature of water is necessary for proper planning.

Water Use in Saudi Arabia: Problems and Policy Implications

Abstract: Saudi Arabia is an arid country with the potenial for acute water shortage. The demand for water has grown substantially against a scarce and dwindling water supply. This growing imbalance has been met mainly by increasing water supply, while water‐demand management has been overlooked. The critical issue is how to reconcile the rapidly rising demand with scarce and depletable resources. This paper demonstrates and emphasizes the need and the urgency of adopting conservation and water‐demand management programs to achieve an acceptable balance between water needs and availability. There is considerable scope for improving the efficiency of water use in various sectors. The government of Saudi Arabia must shift its emphasis from supply development to demand management to avoid wasteful, inefficient uses of critical and nonrenewable water resources. The paper describes the country's water resources, discusses some problems and their implications of water use, and suggests some possible conservation measures...

Microbiology of Drinking Water Treatment: Reclaimed Wastewater

Abstract: The water reclamation plant in Windhoek (South West Africa/Namibia) represents a milestone in water reuse technology (Figure 9.1). Prompted by water shortage, the plant was commissioned in 1969 as the first, and to date probably still the only, plant in the world which directly reclaims drinking water from wastewater for the supplementation of a city’s drinking water supply (Stander and Clayton, 1977).

Water resources development in Costa Rica 1970–2000

Abstract: The estimated overall annual runoff for Costa Rica is 2200 mm which corresponds to an outflow of 3557 m3 s−1. Gross water utilization by hydroelectricity, irrigation, navigation and potable-industrial uses has increased significantly during recent decades. During the period 1970–1987 the percentage of available water used doubled from 6% to 12%. An estimate for the year 2000 indicates that the degree of gross water utilization will increase to about 20%. Water resources availability, therefore, is not a problem per se. There are, however, water scarcity and allocation conflicts due primarily to water pollution and uneven water distribution in time and area. Specific environmental and policy issues are discussed. Among these are the lack of institutional coordination, inadequate water legislation, accelerated environmental degradation and absence of watershed management programmes. A significant change in the national policy toward natural resource management has taken place in the last two years ...

Valuing Urban Water Acquisitions

Abstract: Municipalities typically seek additional water supplies whenever prospective population and economic growth suggests the inadequacy of currently available water supply. The benefit of sup­ ply enhancement is usually construed as avoiding debilitating water scarcity. A more effective approach to planning is to compare the benefits and costs of supply augmentation. The net present value of benefits for a supply increase in a representative Texas community is calculated for alternative scenarios relating to popu­ lation growth, rate growth, and the temporal distribution of the increased supply. Consumer surplus measures are sensitive to all three of these factors and vary from $0 to over $4000 per acre-foot. A notable finding is that the added supply may offer zero values in cases where real water prices increase at an annualized rate of 4 percent (or greater) which is half the rate occurring in Texas from 1981-1985. (KEY TERMS: water rates; supply valuation; water marketing; benefit/cost analysis; consumer surplus.)

Implications of biomass strategy for communities and policies

Abstract: This article summarizes present knowledge of the vulnerability to water scarcity of semi‐arid Third World countries. Their predicament is explained in terms of four parallel modes of water scarcity, superimposed on one another, two of natural origin and two human‐induced. The authors conclude that long‐term planning within the environmental constraints imposed by water scarcity is crucial, and calls for a new awareness among high‐level experts and policy makers. Careful land and water use planning based on the water‐balance method is a key component, but depends on expanding traditional water resources assessment methods developed in the temperate zone to incorporate root zone water storage, differences in groundwater recharge, and landscape zonation in water‐producing v water‐consuming or evaporating areas.

Highlights of the City of Phoenix Water Conservation Program

Abstract: The Phoenix Water and Wastewater Department serves over a million customers in a 420 square mile service area where average rainfall is only 7.5 inches per year. The Phoenix City Council first approved a water conservation program in March 1982, in response to a projected water shortage in a part of the service area. The 1980 Arizona Groundwater Management Act had also made it clear that cities in Arizona would need permanent conservation programs. That legislation requires that all agricultural, industrial, and municipal water users to increase the efficiency of water use to reduce groundwater pumping.

Water Resources Infrastructure: Needs, Economics, and Financing

Abstract: This proceedings, Water Resources Infrastructure: Needs, Economics, and Financing, consists of four page extended abstracts for 45 of the 50 papers presented at the Water Resources Infrastructure Symposium held April 18-20, 1990 in Fort Worth, Texas. This theme generated interest in a wide range of topics such as financing of the infrastructure, cost sharing, maintenance and rehabilitation of urban water resources systems, regionalization of water supplies, and flood and drought management. Besides covering a variety of subjects, the methods of presentation ranged from the theoretical applications of new engineering technologies to case studies of actual successes and failures of completed projects. Thus, this proceedings provides both the practicing engineer and the researcher with a valuable source of information concerning the water resources infrastructure.

Wastewater Storage and Reuse for Irrigation in Israel

Abstract: Water scarcity is a common concern in many arid and semi-arid countries. Shortage of water might be accompanied by groundwater contamination, public health threats, aquifer depletion and well abandonment. Solutions are expensive and may take a long time to achieve, but more immediate actions may also be undertaken: reduce water consumption through conservation, and increase the availability of water supply through wastewater reuse. The efforts invested in water reuse will preserve freshwater for potable uses.

Environmentally sound irrigation projects.

Abstract: Upstream deforestation inaeasedfloodflows and silt loads, destroying these irrigation canals in Tanzania. IRRIGATION IS PRACTISED in many very different environments, some of which have been stable for hundreds of years. It has enabled a vital expansion in the production of foodstuffs that has helped to support greatly increased populations, and has reduced the likelihood of famine in many countries as well as supporting production for industry and export. Yet in issues of resource allocation and environmental impact, few development initiatives raise more debate and controversy than irrigation. In the race to increase output from irrigated production, technologies have often been taken up without a full appreciation of the political, social and economic structures that can provide environmental stability. Thus in irrigation development, whether intensifying traditional schemes or constructing new projects, the scale of potential improvements in production, employment and welfare can often be counteracted by risks of environmental degradation. What have irrigation practitioners learned from the past to help design and achieve environmentally sound irrigation schemes in the 1990s, and what dilemmas do we still face? What new challenges are facing us from new technologies, increasing water scarcity in some areas, and the tough financial climate of the late twentieth century? The 1980s was an important decade for understanding the links between environmental management and development issues. We came to understand that we not only needed to prevent the degradation and loss of land and water resources, but we also needed agricultural systems with reduced dependence on non-renewable

Innovative Ways of Meeting California's Water Needs

Abstract: The California State Water Project has contracted to sell 4.2 million acre-feet of water per year. But, the annual dependable project yield is only about 2.4 million acre-feet. And the demand is growing rapidly, with the population in the SWP service areas expanding by more than 400,000 people each year. At the same time, more water is being requested for fish and wildlife purposes and more stringent water quality requirements are being imposed, which could require more water. This paper presents a discussion of the needs, and the options for future water supplies, which are under study by the California Department of Water Resources. These options include conventional dams and reservoirs, improved conveyance systems, conjunctive use of surface and ground water and water banking. Efforts to reduce demands by water conservation and greater reuse of reclaimed water are being pursued.

A study on the cost minimization of a water supply system with a buffer reservoir and advanced treatment facilities

Abstract: In Japan, almost all of the people can have access to the service of treated water through water supply utilities. However, to realize reliable supply of safe and palatable water, various problems such as frequent droughts and odor and foul taste resulting from raw water pollution should be resolved. Water shortage occurs somewhere in Japan almost every year due to short precipitation and inadequate water resources. The odor and taste problem is related to the poor raw water quality caused by the eutrophication of source reservoirs and rivers contaminated by wastewater. As one of the countermeasures against the water shortage and the raw water pollution, this paper proposes a water supply system with a buffer reservoir, advanced treatment facilities which are composed of biological oxidation unit, GAC adsorption unit, and conventional treatment unit with sedimentation and rapid sand filtration. Then how to, through the abovementioned system, meet quantitive and qualitative criteria of reliable water supply while satisfying the safety and palatability of treated water despite drought and raw water pollution is shown. It is also shown how to minimize the total cost of construction and operation of the system. In minimizing the cost, several combinations of conditions concerning the raw water, as well as those concerning treated water, in quantity and quality are studied. As a result, a contour chart of the unit cost is produced, which explains the relationship between the water quality criteria of treated water and supply quantity conditions as percentage of cutback rate on water demand. Two sheets of contour charts are drawn using such combinations of raw water conditions as the cases of large or middle scale droughts and high or middle levels of river water pollution. As many water supply utilities expect to encounter unfavorable conditions of raw water in quantity and quality, they will find it profitable to introduce the abovementioned system, and then the chart will be very useful for their decision making on countermeasures to deal with the problems.

Government Cooperation in Water Resources Planning and Management

Abstract: The California State Legislators have shown real concern in trying to do something about the clearly identified water shortage. Many bills and funding programs have been proposed to encourage conservation. The State Agriculturalists have taken advantage of these programs and progress is being made. However, conservation alone will not solve the problem and that Federal, State and local support must come forth together for major projects if the objective is to discontinue mining supplies from future generations. Additional aspects of the subject are discussed.

Local system responses to water shortage.

Abstract: Water shortages have become increasingly serious natural resource problems in recent years. In most cases local water systems are responsible for programs to reduce individual water use. The effectiveness of these organizations is related to their ability to obtain information and assistance from other organizations at the local, state, and federal levels. This paper examines the experiences of 28 local water systems in North Carolina in responding to water shortage. Results are based on detailed personal interviews with the main decision maker for each water system. Obstacles to effective water management are evaluated. Sources of information and assistance are identified. Attitudes of respondents about their experiences are analyzed. Smaller systems were found to face more problems in coping with water shortage. They are also in greater need of assistance and information from outside organizations.