Showing papers on "Water conservation published in 1991"

Crop residue management and tillage methods for conserving soil and water in semi-arid regions

Abstract: Soil degradation reduces soil productivity and is a serious problem on much of the land in semi-arid regions. To avert continued degradation, the soil productivity balance must be shifted from degrading processes to conservation practices. Crop residue management and conservation tillage are on the positive side of the balance. When adequate residues are available and conservation tillage is used, soil erosion is greatly reduced and water conservation is enhanced. Water conservation is important for improving crop yields in semi-arid regions, especially where irrigations is not used. A major constraint to residue management in many countries is low production and widespread use for other purposes. In such cases, clean tillage and appropriate support practices such as contouring, furrow diking, strip cropping and terracing may provide adequate soil and water conservation benefits. Where these are not adequate, alternative management practices should be implemented to ease the demand for residues, thus permitting more of them to be retained on the land for soil and water conservation purposes. Some alternative practices include limited or selective residue removal, substituting high quality forages for residues as animal feed, alley cropping, using wasteland areas more effectively, improving the balance between feed supplies and animal populations, and using alternative fuel sources.

The Bureau of Reclamation's new mandate for irrigation water conservation: Purposes and policy alternatives

Abstract: Although the Bureau of Reclamation adopted a new mission as a water management agency, social purposes of the mission and methods of accomplishing the purposes remain undefined. A broad consensus agrees that a central feature of the agency's management program should be irrigation water conservation. This paper describes three purposes of irrigation water conservation: achieving economic efficiency of water allocation, improving environmental quality of western river systems, and satisfying outstanding Native American water claims. Five policy instruments are described as alternative methods of inducing conservation: quantity-based regulation, price-based regulation, transferable water use permits, conservation subsidies, and decentralization of ownership of Reclamation facilities. Two findings are: (1) price-based regulation may not produce water conservation and (2) conservation policy instruments should be chosen with reference to their ability to achieve the purposes of federal water conservation policy. An example illustrates quantitative effects on farm income of the alternative instruments.

Method and apparatus for recycling R/O waste water

Abstract: Waste water discharged from a reverse osmosis unit served by a water feed line and producing potable water is returned to the water feed line for water conservation purposes. After periodic flushing of the reverse osmosis unit, the flush water may be returned to the water feed line or channelled to a drain. After each cycle of operation, any pressure differential between the water inflowing to and water outflowing from the reverse osmosis unit is relieved.

Efficient Spatial Allocation of Irrigation Water

Abstract: In the presence of conveyance losses, the efficient quantity of water applied falls with distance from the water source, but the amount of water "sent" (including conveyance losses) actually increases with distance from the source, except toward the tail end of the inigation system. This implies that if marginal cost pricing were implemented, farmers at the middle and lower reaches of the system would have to pay more money for less water received. The model is illustrated and alternative financing schemes compared for an empirically derived demand function for imgation water. Despite massive public investments in irrigation infrastructure, ex post evaluations of irrigation projects in developed and developing countries indicate that actual benefits are substantially below projected levels. Considerable evidence suggests that these low benefits are largely the result of poor on-farm water use efficiencies and rent-seeking activities that result from water charges that are low and often unrelated to water use (Chaudhry, Repetto, Bowen and Young). For example, farmers near the system headworks are said to consume a disproportionate share of irrigation water, while tail farmers are left with scanty and unreliable residual supplies (Reidinger, Wade). Many governments, faced with increasing political pressure to conserve water and reduce fiscal deficits are considering higher water charges to decrease waste and increase cost recovery from project beneficiaries. There is also increased awareness that low water charges and loosely enforced water rationing guidelines lead to environmental damages and excessive mining of groundwater resources. In general, the problems of water allocation and low user charges contribute to derivative problems in achieving efficiency, equity, fiscal stability, and environmental sustainability.

Value of Water in Irrigated Crop Production Using Derived Demand Functions: a Case Study of South Saskatchewan River Irrigation District

Abstract: Water abundance has led most North American societies to use water freely without priorizing its use. As water scarcity becomes reality in the southern part of Saskatchewan, planners and managers of water require information about the value of water in irrigation, as well as in alternative uses. In this study, the value of water to the producer in irrigation is developed both for the short and long run. The basis of this imputation is a derived demand function for water using linear programming. Water demand was bound to be inelastic at lower prices, and highly elastic at higher prices. The short-run value of water varied between $0.44 and $127.82 (1986 dollars) per acre-foot for different levels of product prices. However, the long-run value was estimated between zero and $1.59 per acre-foot of water.

Looking After Our Land

Abstract: Soil and water conservation projects in sub-Saharan Africa have had a troubled record over the past 50 years. Their failure has had extremely serious consequences especially for those people living in the marginal dry land areas.

Water Conservation Potential From Irrigation Technology Transitions In The Pacific Northwest

Abstract: The effects of price changes on irrigation technology transitions and potential agricultural water conservation in the Pacific Northwest are analyzed using Parks' (1980) modified multinomial logit model. Results indicate that commodity price effects are statistically significant, but they are relatively small with nonprogram crop price effects greater than program crop price effects. Locational factors are also found to affect technology transitions. In the absence of water policy changes, continued irrigation technology adoption by year 2005 will result in average annual water savings of approximately 404,000 acre-feet in the Pacific Northwest.

Water for sustainable development in the 21st century: a global perspective

Abstract: Many arid and semi-arid countries are feeling water crisis already at present, and the problem will become more serious in the 21st century. Global water consumption will increase, 10-fold during this century, and the increasing trend will continue well into the 21st century. This Presidential Address to the International Water Reserves Association discusses the reasons for the water crisis, and the major water issues of the 21st century. Among those issues are water conservation and efficient use of water, water pricing and cost recovery, social and environmental considerations, institutional responses to better management, management of international water bodies and proper analytical frameworks.

The Political Economy of Water Quality Protection from Agricultural Chemicals

Abstract: Growing evidence of surface-water and groundwater contamination has led to demands for federal and state water quality protection policies. Agriculturewill be an important target of such policies. Numerous instances of surface-water and groundwater contamination by pesticides and fertilizers have been recorded, and one study estimates that the drinking water of 50 million people in the U.S. is potentially contaminated by agricultural chemicals (Hallberg, Nielsen and Lee). A number of policy approaches for reducing agricultural impacts on water quality are being discussed or implemented. These include extending the cross-compliance provisions of the 1985 and 1990 Farm Bills to include water quality protection, prohibitions on the use of certain chemicals (e.g., Proposition 128 in California), incentive payments for water quality protection schemes in the 1990 Farm Bill, and research and development on “low-input” production methods. In this paper we outline several of these approaches. We consider general approaches rather than specific proposals so that the outline is framed in broad terms. We also present economic and political criteria for evaluating the policy options and some tentative rankings.

Increasing Block-Rate Prices for Irrigation Water Motivate Drain Water Reduction

Abstract: This chapter reviews the potential role of price incentives in modifying farm-level irrigation decisions to coincide with socially optimal choices when drainwater contains toxic elements. An optimization framework for irrigation districts facing drainwater discharge constraints is presented and implications for water pricing structures are discussed. Details of a block-rate pricing program that was implemented in a California irrigation district during 1989 are described and farm-level responses to the program are discussed. Results of the program include reductions in applied water for some crops in 1989 and reductions in the total volume of drainwater collected in the district.

Water marketing and water rights transfers in the lower rio grande valley, texas∗

Abstract: Water marketing, which involves the purchase or transfer of water supplies or rights between a willing buyer and seller, represents on strategy for redistributing water resources among competing users. Most frequently, municipalities purchase agricultural water rights to augment their existing supply and help meet projected water demand. In Texas, the most active water market is in the lower Rio Grande Valley where the cities of Brownsville, Harlingen, and McAllen have acquired surface water rights for converting water from agricultural to municipal and industrial uses. The existence of the Rio Grande Watermaster simplifies the procedure for transferring surface water rights, helps address problems such as the maintenance of instream flow and protection of senior water rights holders, and serves as an administrative model for water resource management.

Water supply and demand

Abstract: Agriculture plays an important part in California's economy and irrigation water is an essential factor in agriculture's success. However, California faces serious water supply issues, in which agricultural uses must compete with environmental uses and the demands of a growing population. Several options are open to policymakers regarding the state's supply, demand and transport of water. California's primary source for water is precipitation-rain and snowfall. In a normal precipitation year, the state will receive about 200 million-acre-feet (maf) in precipitation and imports from Colorado, Oregon and Mexico (DWR 2009, 1-4). Of the total supply, about 60 percent is used directly by vegetation or cropland or flows to salt sinks like saline aquifers or the Salton Sea. The remaining 40 percent, or about 80 maf, enters stream flows or wells and is distributed among agricultural, urban and environmental uses (DWR 2009, 1-4). About 30 maf is used for agricultural irrigation and about 9 maf enters urban and industrial uses. Most of the precipitation occurs in the north and east of the state. However, irrigation water demand is highest in the state's valleys and coastal plains so a storage and transport system was developed to capture this runoff and deliver it during the dry months. California has more than 1,200 surface water reservoirs, in addition to an extensive network of canals, levees, and treatment plants (see Figure 1). Since most of the urban demand lies in the south and along the coast, a series of pumps must transport water at great expense over mountain ranges. The irrigation provided by this system, together with the Mediterranean climate through much of the state, allows the cultivation of a great variety of crops. However, precipitation varies significantly from year to year and water supplies are therefore unpredictable. Moreover, current climate change models suggest that the Sierra Nevada snowpack is likely to decrease in the future (Kapnick and Hall 2009). Recently, increased efficiency in usage has also contributed to the state's ability to meet water needs. However, urban and industrial water demand has risen as the population has continued to grow. Urban water usage, including residential, commercial and industrial uses, is about 8.7 million acre feet annually and growing (DWR 2009, 4-10). Environmental and agricultural water usage vary significantly by year, depending on drought conditions. In a typical year, agriculture will irrigate about 9.6 million acres with 34 million acre-feet of water (DWR 2009, 4-10) or …

Effects of Input Quality and Environmental Conditions on Selection of Irrigation Technologies

Abstract: The use of modern irrigation technologies has been proposed as one of several possible solutions to water scarcity, limited drainage, and associated problems in irrigated agriculture. These technologies should be assessed within economic decisionmaking frameworks which could be applied to guide farmers and water districts in irrigation and technology choices, to assist public policymakers in designing policy instruments to increase conservation and reduce drainage and runoff, and to aid developers of irrigation technologies in the design and marketing of new products. An economic model is developed in this chapter, which includes many of the aspects previously developed, and also takes into consideration new aspects such as weather conditions and the dual effects of soil and water quality. The results provide several general insights regarding the impacts of different irrigation technologies and input qualities on productivity and profitability. The results also illustrate differences in outcomes associated with crop selections as affected by weather, input quality, and technology selection.

Subsurface drip produced highest net return in Westlands area study

Abstract: Cotton was produced using subsurface drip, low-energy precision application (LEPA), scheduled furrow, and conventional furrow irrigation systems in 1989. Subsurface drip irrigation produced the highest net return to the grower through increased cotton yields. Significant water conservation was achieved with both pressurized irrigation systems (subsurface drip and LEPA). However, computer aided scheduling of furrow irrigation did not result in significant water savings. Pressurized irrigation systems may offer the flexibility and control necessary to significantly limit unnecessary water additions to the shallow groundwater table.

The Emerging Demand-Side Era in Water Management

Abstract: Decreasing sources of supply are resulting in a trend toward demand-side alternatives in water management and toward striking a balance between new source development and conservation. This article describes some steps that are being taken across the United States to restrict demand, including the setting up of water conservation offices, committees, coordinators, and conferences; the planning of conservation programs by utilities and water districts; and the implementation of conservation measures by the residential, commercial, industrial, and agricultural sectors. Surely the vast cycles by which water is drawn up into the clouds to return to the earth could never be touched wrong

Encouraging Water Saving: the Role of Knowledge, Attitudes, and Intention

Abstract: Few would doubt the need, in today's world, to promote behaviours that actively conserve environmental resources. At a general level, this often involves encouraging behaviours that involve a short-term cost for the individual in order to avoid a long-term negative outcome for the community. Examples of such behaviour are, taking the trouble to turn off lights to save electricity and fixing leaking taps to conserve water. It is these latter kinds of behaviours, namely those associated with the efficient use of water resources, which are the focus of this paper.Faced with the high economic and practical costs of attempting to supply unlimited amounts of water for the Melbourne metropolitan area, the Board of Works has sought, by a number of means, to persuade its consumers to use water more efficiently. One aspect of its strategy was to promote water conservation within the educational curriculum by designing various educational materials and programs for different school levels. These and other promotional materials were made available to schools in the Melbourne metropolitan area in 1988. Prior to the distribution of this material, the data reported in this paper were gathered as the first stage of a longitudinal evaluation of the Board's education strategy.The assumption underlying the Board of Works' educational program was that behaviour change is preceded by changes in knowledge. For example, it was assumed that a person, knowing something about the water cycle, and the system by which water is fed into our taps, would believe that it is important not to waste water. The result would be active water conservation in daily life. Some basis for this assumption has been provided by the report on domestic water use in Perth, Western Australia (Metropolitan Water Authority, 1985), where knowledge and attitudes were found to be predictors of actual water consumption. Such an assumption is based in a general way on a cognitive or information processing model of behaviour change, in which changes in behaviour are seen as proceeding from changes in relevant information or knowledge. This cognitive model is the basis for many social education programs both in schools and in the community. For example, the Quit Campaign and the AIDS campaign have both used strategies that aimed to inform the public about particular health-related behaviours.

Closure of "Water Requirements Versus Water Availability in Saudi Arabia"

Abstract: Water demand in the Kingdom of Saudi Arabia has increased from 1750 million cubic meters (Mm3) in 1975to more than 9,600 Mm3 in 1985, a five-fold increase in ten years. At the same time increase on the supply side through water recycling and seawater desalination has been from around 18 Mm3 to 605 Mm3 during the same period. The development of these additional water supplies have been, however, far short of the increase in water demand, with groundwater making up the difference. This paper examines the above problem from the viewpoint of supply-demand balance. First, the paper assesses the surface and groundwater resources of the Kingdom, and the present as well as the future conditions of sea water desalination and water cycling. The water demands of the various use sectors are given followed by projections of future water demands. The third phase compares the water supply-demand situation under present and future conditions. From this comparison it was evident that unless there is a change in the current water use practices, groundwater, the major water resource of the Kingdom, will be mined in few decades and the extent that its usefulness may be severely diminished as a resource. When this develops, a severe water crisis will occur. The crisis can be reduced in severity, or averted, by taking the needed steps to bring into balance the annual water use with annual water supply.

Irrigation Practices in Illinois

Abstract: Biweekly and total irrigation amounts and irrigation scheduling practices were monitored at representative sites in central Illinois during the 1988 and 1989 growing seasons. The purpose was to gather baseline information on average quantities of irrigation water used in normal and drought years and on the general efficiency of irrigation operations in the subhumid climate of Illinois. Soil water-holding capacity is the most important factor in determining irrigation amounts, explaining about 65 percent of the variability in irrigation totals. Other important factors in explaining irrigation variations include weather changes, individual farmer idiosyncrasies, and crop differences. In general, irrigation farmers in Illinois appear to be applying appropriate amounts of irrigation water at appropriate times in the growing season, based on their soil type, crop type, and total evaporative losses. Reference: Bowman, Jean A., and Brian C. Kimpel. Irrigation Practices in Illinois. Illinois State Water Survey, Champaign, Research Report 118, 1991. Indexing Terms: Evaporation, Illinois, irrigation, irrigation efficiency. irrigation in subhumid climates, irrigation operation and maintenance, irrigation practices, irrigation scheduling, soil water, water balance, water utilization. STATE OF ILLINOIS HON. JIM EDGAR, Governor DEPARTMENT OF ENERGY AND NATURAL RESOURCES John S. Moore, B.S., Director BOARD OF NATURAL RESOURCES AND CONSERVATION John S. Moore, B.S., Chair Robert H. Benton, B.S.C.E., Engineering Donna M. Jurdy, Ph.D., Geology H.S. Gutowsky, Ph.D., Chemistry Roy L. Taylor, Ph.D., Plant Biology Robert L. Metcalf, Ph.D., Biology Judith S. Liebman, Ph.D. University of Illinois John H. Yopp, Ph.D. Southern Illinois University STATE WATER SURVEY DIVISION RICHARD G. SEMONIN, Chief 2204 GRIFFITH DRIVE CHAMPAIGN, ILLINOIS 61820-7495

Reuse of agricultural drainage water to maximize the beneficial use of multiple water supplies for irrigation

Abstract: This chapter provides conceptual arguments and empirical evidence to show that the blending approach typically used for water quality protection can result in economic losses to the agricultural community as a whole. A better strategy is suggested for dealing with the “disposal” of saline agricultural drainage waters which provides greater practical benefit to be derived from the total water supply than blending does. In this strategy the drainage water is intercepted, isolated from the good-quality water, and reused for the irrigation of suitably salt-tolerant crops in the same project. Ultimately, a greatly reduced volume of secondary drainage water is disposed of or treated in some manner other than blending.

Population and water resources.

Abstract: The Population Program of the National Audubon Society has published an overview of the water supply problems we face and the effect of population growth on these problems especially as they apply to developing countries. Water potential depends on the amount of water available locally or regionally and on the way in which people manage that supply. Improper water management can limit this otherwise renewable resource. For example human activities such as rapid population growth and industrial processes increasingly pollute water supplies. Humans need to value water adequately and to improve water conservation efforts and management. Otherwise the future of life on the planet may be in jeopardy. Business and governments must begin long-term thinking and avoid focusing on short-term profits. Lack of adequate water supplies has already contributed to drought starvation and political chaos in semiarid developing countries. These events will expand unless water crises are addressed. On a global scale inattentiveness to water supplies has already brought about the destruction of wildlife and its habitat contamination of drinking water supplies loss of critical farmland and a declining quality of life. Eventually nature will control the abuses of its natural resources. sustainable development can be achieved however if humans commit themselves to international cooperation population stabilization water conservation and wise management of water and other natural resources. Major subjects included are population and water resources water usage population growth and increasing demand water quality wetlands and estuaries increasing energy demands and recommendations.

Subsurface water quality and quantity from the standpoint of irrigation and livestock

Abstract: Field studies were undertaken at the Oyo North Agricultural Development Project (ONADEP), Shaki, Nigeria in 1988 and 1989 to evaluate the reliability and quality of subsurface water sources in relation to irrigation and livestock usage. Based on data from 22 water samples, 15 soil types, seasonal consumption of water for 10 major crops and extensive hydrogeological records, it was established that (i) alkalinity and salinity hazards are low, hence the groundwater of the study area is suitable for irrigation, (ii) excessive boron levels might restrict the usage of the groundwater of the study area for livestock, (iii) subsurface water sources, estimated at about 31,000 ML per annum is capable of satisfying only 12% of agricultural and livestock water demand of the study area, and (iv) the area under consideration is not endowed with abundant surface and subsurface water as shown by previous studies.