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1 DIMENSIONS OF DROUGHT MANAGEMENT FOR PUBLIC WATER SUPPLIES (Colloquium Keynote Address) Gilbert F. White Institute of Behavioral Science, University of Colorado, Boulder Among the several hazards to which public water supply management is subject, drought imposes a few distinctive problems as well as shares in others common to most natural resources use. It comes on very slowly, its losses are particularly amenable to short-term mitigation by individual consumers, and it has a unique spatial pattern of appropriate remedial or preventive measures. The facets of the problems involved are so numerous that individual ones must be touched on only briefly if all are to be identified in a balanced and comprehensive fashion. Accordingly, this chapter deals with numerous dimensions of public water supply and drought without exploring any one in depth. Out of the rapid, broad review may emerge a perspective on the detailed chapters to follow. DIMENSIONS In beginning a more detailed examination of drought causes and occurrences, management options, the notion of acceptable risk, and their institutional implications, it may be helpful to place that management in perspectives of time, place, and quality. Drought is only one of the shocks that may disrupt the range of public services provided by a city. While thus far defying precise forecasting, it has a long period of onset with special problems of uncertainty. It's possible severity differs greatly from one area to another according to climate, ground-water availability, and competing water uses. A good deal is known about the modes of economic analysis requisite to choice of 1 1
-12- effi~ient options. Much has been learned in recent years about the behavioral and legal constraints on mitigating action. Nevertheless, it appears that effective means for cities to cope with drought are handicapped by a few deficiencies in data and in analytical methods, and that public perspectives and legal constraints on drought management are changing and may be expected to continue to change. This report is intended to illuminate the gaps in sight. The term "drought" is used in this context to mean a period of time during which, as a result of abnormally low precipitation, the supply of surface water and water in shallow aquifers is reduced below that safe yield expected in most years, the recurrence interval being set by hydrologic analysis or the vulnerability of water supply systems. It does not have the precision of agricultural definitions of drought, such as the Palmer index, in which deficiencies of precipitation are determined by relations to evapotranspiration, soil moisture, and crop needs. WATER AMONG OTHER PUBLIC SERVICES The provision of water is only one of the services most municipalities regard as essential, whether supplied by public or private agencies. It competes with sewerage, electricity, gas, streets, trash collection, fire fighting, police, and welfare aims in seeking funds and managerial attention. This is important to remember in explaining why water improvements and planning in some cities may seem to be neglected in favor of more ~ ~~ ~ programs to control crime of waste. dramatic or complicated or speed up traf fic or dispose DROUGHT AS ONE HAZARD AMONG MANY Drought is only one of the wide range of natural and technological hazards to which a public water supply is vulnerable. On the natural side, many urban systems are subject to severe shocks to supply, treatment, or distribution as a result of floods, hurricanes, and earthquakes (Burton et al., 1978~. (Landslides, tornadoes, volcanic eruptions, and cold spells are on the whole less threatening to entire systems.) On the
-13- technological side, the dangers of ground-water contamination, explosions, chemical spills, large fires, and equipment breakdown are well recognized. Possibly a more severe and widespread hazard is that of short-sighted, incompetent management that fosters, often complacently in the face of supplies that seem to be satisfactory and cheap, deferred maintenance and shoddy planning. Comparing these several hazards in Table 1-1, it is clear that drought, while of low frequency, has a much longer onset time and duration than the others, thus providing greater opportunity for preparations to cope with its effects and to carry out such measures on a sustained basis. Taking into account the physical characteristics of the drought hazard and the economic and political . consequences of sudden disruptions of water systems, it can be seen that managers faced with allocations of meager funds for improvement may be inclined to rate the drought as less important. For example, a waterworks TABLE 1-1 Characteristics of Selected Hazards to Public Water Supplies Characteristics Hazard Onset Duration Frequency (days) (days) - Natural Drought rare slow long (>730) (>750) Flood medium rapid short (0.1-10) (0.1-4) Hurricane medium rapid short (2-5) (0.~-1) Earthquake very rare instantaneous very short (0.001) (0.5) Technological Explosion very rare instantaneous short to med. Chemical spill very rare instantaneous short to med. Equipment failure very rare instantaneous short to med. Ground-water contamination medium slow long (>750)
14 operator in a town along the Wasatch Front in Utah may judge the overnight destruction by an earthquake of aqueducts, well pumps, and distribution reservoirs as more serious than the slow dwindling of streamflow and reservoir capacity over three years. Or, a waterworks operator drawing on a Delaware River supply may fear the panic and interruptions resulting from disclosure of ~ ~ · e new, carcinogenic substances In the storage reservoir or an epidemic of giardiasis more than the prospects of - drought. Similarly, an Albuquerque city council could be more profoundly disturbed by a discovery that its aquifer is contaminated by organics linked with disease prevalence, than that a drought might occur. TIME Looking broadly at the temporal dimension, it would appear that drought has claimed national attention in three major periods, and is the ob ject of two sets of speculation, one historical, the other prospective. The first widespread appraisal ot public water supply , . . , . . . ~ . .~ ~ shortages attributable to drought was stimulated by the great drought of 1934 and 1936. A first canvass of state sanitary engineers in suffering communities was made by the American Water Works Association (White, 1935~; the U.S. Geological Surrey and U.S. Public Health Service later began more penetrating reviews. Notice again was taken of difficulties with supply beginning in 1953-1954, and USGS analyses were extended (Wolman, 1955~. The Eastern Seaboard drought of the 1960s inspired a series of more detailed appraisals of water supply adequacy in the event of persistently low precipitation. These included the Corps of Engineers Northeastern United States Water Supply Study (U.S Corps of Engineers, 1975) and the pioneering appraisal of adjustment alternatives by Russell et al. (1970~. Coming along with earlier, 1950s advances in economic analysis of water resources investments by Kneese (1959), McKean (1958), Eckstein (1958), Hirshleifer et al. (1960), Krutilla and Eckstein (1958), Maass et al. (1962), and others, the methods of examining the benefits and costs of investment options were specified for the first time. The notion of alternatives in water management had gained wide acceptance between the late 1950s and 1960s, so that by the fresh drought episodes of the 1970s there
-15- began to be systematic reviews of the great variety of measures to increase supply or reduce consumption (Davis, 1968; Committee on Water, 1966~. Russell et al. investigated 15 types of adjustments made by 39 communities (see Table 1-2~. It remained for the long dry spells of the 1970s to set off a series of investigations of the precise conditions in which consumers would adopt water conservation measures. D. D. Baumann, J. H. Sims, J. J. Boland, W. H. Bruvold, and many others began to look at individual and community response to drought-restricted water supplies. Water conservation methods were evaluated in 1979 and 1982, and demand forecast approaches were appraised (Baumann et al., 1979; Boland et al., 1981 and 1982~. They carried this a further, reasonable step to the specification of methods by which community planners could effectively canvass and compare their options with an eye to public acceptance of unconventional supply and demand management measures (Sims et al., 1982~. During recent years the time horizon has extended backward and forward. Using tree-ring, clay verve, TABLE 1-2 Adjustments to Drought Made by 39 Massachusetts Communities (Percentage Adopting) and To Decrease Withdrawals To Increase Supply Restrictions Domestic 87 Industrial 59 New sources Reservoirs 13 Ground water 49 Price 15 Improve existing Reservoir 26 Meter 8 Ground water 16 Leak repair 8 Emergency supplies 26 23 18 Surface Ground Purchase Weather modification 2 SOURCE: Russell et al. (1970) .
-16- archeological findings, it has become-apparent that the disappearance of the Anasazi civilization of the Southwest during the thirteenth century A.D. coincided with a drought of greater duration and depth than those in recorded history. Regardless of any possible causal relation between the two, the lack of established change in climate patterns since that period supports the suggestions that the Southwest region, including the Colorado Basin, may again experience a similar episode and that it would be prudent to plan for that recurrence. Such an event could be thought of as the ultimate test for drought management in that region. Looking ahead to a drought period in the twenty-first century when the climate warming induced by buildups of carbon dioxide and other gases in the atmosphere might begin to increase temperatures and change precipitation patterns, it is now speculated that a chronic condition of moisture shortage might unfold (Revelle and Waggoner, 1983~. It might not be cyclical if it were to take place; a new base on which drought deviation might be calculated then would be established. From both the historical and the futuristic speculations, the severity of possible future droughts is increased. It should be observed, however, that the social effects upon cities in the Southwest are not as likely to disrupt the social fabric as would similar magnitude events in the humid eastern regions. This would be because of the prevailing patterns of urban population, water use, and ground water (Engelbert and Scheuring, 1984~. SPACE At least four spatial dimensions of the urban water supply situation interact to affect in quite different ways the vulnerability of cities to drought. These are population size, rates of growth or decline, ground-water availability, and agricultural use of water. Records of past drought episodes suggest that, with notable exceptions, it is the smaller municipalities and those with poor planning and meager surface water supplies that have higher probabilities of suffering shortage. Even where ground water of potable quality is physically available, towns may encounter shortage through poor management. A study of small Colorado towns illustrates this relationship (White et al., 1980~.
-17- It is sometimes argued that rapidly growing cities are more vulnerable to distress induced by drought than cities with no growth or very slow growth. Over periods of a few years this may be true, but over decades the opposite might hold. cities not faced with early expansion may neglect planning for increasing supply or improving management (Ellinghouse and McCoy, 1982~. Those who already foresee a limit to available supply may be obliged to give explicit consideration to the probability that projected additional supplies may fall short of demand in dry periods. Those with access to good quality ground water often find ways of improvising in times of shortage or of providing in advance for reserves to be available. Thus, cities located in the glaciated Central Plains may be more likely to provide reserve or emergency supplies when surface sources attenuate than those in the unglaciated Central Plains (Heath, 1984~. Growth in ground-water withdrawals for public supply has been modest in comparison with that for agricultural uses (Solley et al., 1983~. Major increases in such withdrawals have been in the western states, particularly the Great Plains states. A comparison of ground-water availability with proportions of supply currently drawn from surface sources would give a first, rough delimitation of areas where the ground-water alternative might be promising. Of basic importance is the availability of water in agricultural uses. Passing over, but not dismissing, the legal barriers to transfer of water rights, it is possible in large areas of the country practicing irrigation from collective distribution systems that, in the event of water shortage, water could be diverted from agriculture to municipal and industrial uses. Temporary loans during dry years are made by farmers without suffering distress. The Asilomar Conference developed the general argument that the expanding needs from urban users in the western states could be met by transfers from irrigation without crippling U.S. agriculture and with only local areas of social dislocation (Engelbert and Scheuring, 1984~. In areas where cities favor permanent acquisition of irrigation rights rather than developing new sources, the effects on prime land however, may be destructive (Anderson et al., 1976~. The statistics on national water withdrawals and consumptive use by main sectors of the economy are well
-18- known (U.S. Water Resources Council, 1978~. Aggregated national figures are not meaningful, but the regional data on consumptive use as a percentage of renewable supply show those areas where reductions in irrigation use could remedy temporary shortages in urban supply (USGS, 1984~. Public supplies account for only a small proportion, less than 7 percent of withdrawals and 5 percent of consumption. ORGANIZATION Institutional and administrative dimensions can be thought of as falling into four classes: organizational competence, legal and administrative capacity, technical skill in analysis, and basic data for analysis. Organizational incompetence already has been noted in connection with size of cities. No doubt the smaller ones as a class are most likely to display it, but even the largest U.S. city at one period suffered dramatically from inadequate planning. It may be asked whether the prevailing flows of information and federal-state-local planning arrangements provide assurance that such crises will not recur. On the legal and administrative fronts, the exploration of the opportunities and constraints inherent in state water law and federal claims is going forward rapidly. Spurred by recent Supreme Court decisions, the possibilities for interstate transfers of water rights are receiving searching attention. Assertions of Native American and federal reserve claims are troubling communities that might have considered their supplies as certain. Largely at the initiative of environmental advocacy groups, pioneering efforts have been launched to promote water conservation measures in the Imperial Valley and to manage demand as a substitute for structural measures in the Denver metropolitan area. Less conspicuous but possibly as significant is the evolution of regional or district institutional machinery to plan and operate water and waste disposal systems encompassing several cities. There now is sufficient time, for example, to appraise the effectiveness of the Delaware Basin compact accords and organization in dealing with the current low flows. The Clean Drinking Water Act of 1974 complicated the planning of community response to temporary supply shortage. By requiring states to exercise regulation of
-19- quality and to provide information on current water quality, it made it more difficult for communities to turn to substitute supplies or to justify continuing with supplies that have been impaired by contamination and concentration. Although there is high sophistication in some of the methods available for weighing _ _O ---O the economic effects of options In managing supply and demand, there also is challenge in trying to make those practically useful to city officials and consultants. The Baumann group made such a down-to-earth effort (Planning and Management Consultants, 1980 and 1981.) The Purdue examination of the acceptability of water conservation and associated wastewater measures to government officials and their publics was another step in helping specify the conditions in which community planning to prevent shortage can gain financial support (Potter et al., 1978~. Federal attempts to promote water conservation launched in 1978 continue on a reduced scale (U.S. GAO, 1983~. Reviews of promising management techniques are available (U.S. OTA, 1982~. In a broad sense, every improved method of identifying and evaluating choices in multiobjective water planning may further that end. But the more traditional economic analysis is not often harnessed with behavioral investigations of the circumstances in which public officials and consultants use new information, of consumer attitudes and action toward water conservation measures, of the long-time effects of pricing policies, and of the costs and benefits of undertaking no mitigation actions. As a matter of record, no U.S. city has gone without drinking water in the face of crippling drought. None, like the Anasazis, has moved away. All sorts of emergency measures are being or may be taken, including rationing, temporary supplemental sources, intermittent service, and hauling water. In Colorado during the 1970s drought, the most ineffective municipalities resorted to such measures and were rewarded by receiving state and federal emergency financial assistance. We lack full, discerning estimation of the whole set of effects of taking emergency measures on public health, on financial stability, and on the political stances of officials and legislators in time of emergency. It has been suggested that agreement on some acceptable level of risk from drought, such as the analogous setting of the one percent chance flood for design of flood insurance and other floodplain
-20- management measures, might be beneficial. However, the wisdom of adopting such criterion for drought is doubtful. For certain areas and in circumstances in which a blanket national system of flood insurance is imposed hastily, it may be warranted. In the long run, however, it discourages evaluation of the particular combination of resources use gains and flood losses that affect the productivity of a given floodplain, and it encourages a false sense of security in areas subject to less frequent floods. Surely there are more suitable means of establishing acceptable drought risk, area by area. CONCLUDING REMARKS By way of conclusion and as a means of generating discussion of some of the conventional wisdom in the field, I offer a few observations about the state of the science--and the art--of drought management. The long onset times and duration of droughts should make it possible to refine the forecasts of moisture shortage so as to render them more useful to waterworks operators. The experience with forecasting of the probability of hurricane landfall might offer lessons as to pitfalls and opportunities. The provision of suitable data and technical assistance to municipal governments lacking the competence or willingness to anticipate drought currently is far from effective, and there is question as to how it might be enhanced. The innovation and testing of new legal and administrative devices to permit municipalities to join in water management, to operate a market for water rights, and to share experience in planning and gaining public acceptance for water conservation measures deserve vigorous support beyond what is already under way. REFERENCES Anderson, R. L., N. L. Wengert, R. D. Hal, and others. 1976. The Physical and Economic Effects on the Local Agricultural Economy of Water Transfer from Irrigation Companies to Cities in the Northern Denver
-21- Metropolitan Area. NRED, Economic Research Service, Ft. Collins, Colo. 48 pp. Baumann, D. D., and others. 1979. The Role of Conservation in Water Supply Planning. Prepared for the Institute for Water Resources, Fort Belvoir, Va. 117 pp. Boland, J. J., D. D. Baumann, and B. Dziegielewski. 1981. An Assessment of Municipal and Industrial Water Use Forecasting Approaches. Prepared for the Institute for Water Resources, Fort Belvoir, Va. 162 PP Boland, J., B. Dziegielewski, D. Baumann, and C. Turner. 1982. Analytical Bibliography for Water Supply and Conservation Techniques. Prepared for the Institute for Water Resources, Fort Belvoir, Va. Burton, I., R. W. Kates, and G. F. White. 1978. The Environment as Hazard. Oxford University Press, New York. 240 pp.- Committed on Water. 1966. Alternatives in Water Management, National Academy of Sciences, Washington, D.C. 52 pp. Heath, R. C. 1984. Ground-water Regions of the United States. Water Supply Paper 2242. U.S. Geological Survey, Washington, D.C. 78 pp. Davis, R. K. 1968. The Range of Choice in Water Management: A Study of Dissolved Oxygen in the Potomac Estuary. 196 pp. Johns Hopkins Press, Baltimore, Md. Eckstein, O. 1958. Water-Resource Development: The Economics of Project Evaluation. Harvard University Press, Cambridge. Mass. 300 up. _ ~ ~ A Ellinghouse, C., and G. McCoy. 1982. The Effects of Water Conservation on New Water Supply for Urban Colorado Utilities. Colorado Water Resources Research Institute, Ft. Collins, Colo. 133 pp. Engelbert, E. A., and A. Foley Scheuring (eds.~. 1984. Water Scarcity: Impacts on Western Agriculture. University of California Press, Berkeley. 500 pp. Hirshleifer, 3., J. C. De Haven, and J. W. Milliman. 1960. Water Supply: Economics, Technology, and Policy. University of Chicago Press, Chicago, Ill. 378 pp. Kneese, A. V. 1959. Water Resources: Use. Federal Reserve Bank, Kansas City, Mo. 68 pp. Krutilla, J. V., and O. Eckstein. 1958. Multiple Purpose River Development. Johns Hopkins Press, Baltimore, Md. 301 pp. Development and
-22- Maass, A., M. M. Hufschmidt, R. D orfman, H. A. Thomas, Jr., S. A. Margolin, and G. M. Fair. 1962. Design of Water-Resource Systems. Harvard University Press, Cambridge, Mass. 620 pp. McKean, R. N. 1958. Efficiency in Government Through Systems Analysis. John Wiley, New York. 336 pp. Planning and Management Consultants, Ltd. 1980. The Evaluation of Water Conservation for Municipal and Industrial Water Supply--Procedures Manual. Prepared for the Institute for Water Resources. Institute for Water Resources, Fort Belvoir, Va. 73 pp. Planning and Management Consultants, Ltd. 1981. The Evaluation of Water Conservation for Municipal and Industrial Water Supply--Illustrative Examples. Report 82-C1, submitted to the Institute for Water Resources, Fort Belvoir, Va. 356 pp. Potter, H. K., A. K. Taylor, and G. M. Grossman. 1978. Systematic Development of Methodologies in Planning Urban Water Resources for Medium Size Communities. Water Resources Center, Purdue University, West Lafayette, Ind. 35 pp. Revelle, R. R., and P. E. Waggoner. 1983. Effects of a carbon dioxide-induced climate change on water supplies in the western United States, in Board on Atmospheric Sciences and Climate, National Research Council, Changing Climate: Report of the Carbon Dioxide Assessment Committee. National Academy Press, Washington, D.C. Pp. 419-432. Russell, C. S., D. G. Arey, and R. W. Kates, with the assistance of D. Baumann and D. J. yolk. 1970. Drought and Water Supply: Implications of the Massachusetts Experience for Municipal Planning. Johns Hopkins Press, Baltimore, Md. 232 pp. Sims, J. H., D. D. Baumann, J. J. Boland, K. Alley, and B. Kranzer. 1982. Consumer Adoption of Water Conservation. Southern Illinois University, Carbondale. 200 pp. Solley, W. B., E. B. Chase, and W. B. Mann IV. 1983. Estimated Use of Water in the United States in 1980. Circular #1001. U.S. Geological Survey, Washington, D.C. 56 pp. U.S. Corps of Engineers. 1975. Northeastern United States Water Supply Study: Interim Report--Critical Choices for Critical Years. North Atlantic Division Corps of Engineers, New York, 88 pp.
23 U.S. General Accounting Office. 1983. Water Conservation: An Update of Federal Activity. General Accounting Office, Gaithersburg, Md. 28 pp. U.S. Geological Survey. 1984. National Water Sugary 1983--Hydrologic Events and Issues. Water Supply Paper 2250. U.S. Geological Survey, Washington, D.C. 243 pp. U.S. Of fice of Technology Assessment. 1982. Use of Models for Water Resources Management, Planning, and Policy. U.S. Government Printing Office, Washington, D.C. 242 pp. U.S. Water Resources Council. 1978. The Nation's Water Resources--1975-2000. U.S. Government Printing Office, Washington, D.C. 4 vols. White, A. U., A. N. Di Natale, J. Greenberg, and J. E. Flack. 1980. Municipal Water Use in Northern Colorado: Development of Efficiency-of-Use Criterion. Colorado Water Resources Research Institute, Ft. Collins. 123 pp. White, G. F. 1935. Shortage of public water supplies in the United States during 1934. Journal of the American Water Works Association 27~7~:841-854. Wolman, A. 1955. Providing Reasonable Water Service. Journal of the American Water Works Association 47~1~.
