Water Scarcity: Impacts on Western Agriculture

Preferred Citation: Engelbert, Ernest A., and Ann Foley Scheuring, editors Water Scarcity: Impacts on Western Agriculture. Berkeley: University of California Press, c1984 1984. http://ark.cdlib.org/ark:/13030/ft0f59n72f/

Water Scarcity Impacts on Western Agriculture Edited by Ernest A. Engelbert with Ann Foley Scheuring UNIVERSITY OF CALIFORNIA PRESS

Berkeley · Los Angeles · Oxford

© 1984 The Regents of the University of California

Preferred Citation: Engelbert, Ernest A., and Ann Foley Scheuring, editors Water Scarcity: Impacts on Western Agriculture. Berkeley: University of California Press, c1984 1984. http://ark.cdlib.org/ark:/13030/ft0f59n72f/

PREFACE This publication is the product of an interdisciplinary conference on water problems in the western United States held in Monterey, California, in September, 1982. The primary purpose of the conference and this volume has been to assess the impacts on local, state, national and international communities of limited water supplies for agriculture in the semiarid West. This vast area of the nation is faced with important decisions in the management of declining water supplies if a prosperous agricultural economy is to be sustained. Planning for the conference began in 1978 under the sponsorship of the Directorate on Arid Zone Ecosystems, a part of the United States Man and the Biosphere Program. The Man and the Biosphere Program is an

international effort under the auspices of UNESCO to study the relationships of man to changing environments in various regions of the world. Because the future of western agriculture in the United States has significance for the economies and semiarid regions of other countries, the Organizing Committee of the conference concluded that a careful analysis of what was happening in the American West would have international interest and relevance. The conference and this volume represent an interdisciplinary effort to deal with the subject from both a natural and social science perspective. The Organizing Committee identified the topics and invited over seventy specialists from diverse disciplines representing the academic community, private industry, and the public sector to prepare papers and discussants' comments for the conference. Over two hundred persons participated in four intensive days of presentations and discussions of the papers. The participants represented a broad spectrum of experience, views and interests, including farmers, businessmen, bankers, planners, analysts, environmentalists, community leaders, elected officials, and representatives of other concerned organizations. They reviewed and critiqued the prepared presentations and made substantial contributions to the analyses. Following the conference the authors were given the opportunity to revise their papers and comments, and, in some cases, to include overlooked but relevant points. This volume is the combined product of the revised papers and conference input. To provide integration of subject matter, the papers have been organized under section and chapter headings and placed in appropriate sequence.

― viii ― No one who participated in this educational undertaking would conclude that all topics involving water and agriculture in the semiarid West have been adequately covered. Indeed, as both the Introduction and the Summary show, many issues remain unresolved. However, the Organizing Committee believes that a searching focus has been given to this subject and public attention called to what is becoming an increasingly critical aspect of the nation's economy. Thus we hope that this volume will be informative and useful for everyone who is concerned with future water supplies for agriculture in the West. ROBERT M. HAGAN CHAIRMAN, ORGANIZING COMMITTEE

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ACKNOWLEDGMENTS Many organizations and individuals contributed to the planning and organization of the conference and publication on Limited Water for Agriculture in the West: No Simple Solutions. Grateful appreciation for their assistance is made to the following groups and persons: · Sponsors who provided financial, facilitative and moral support which made this activity possible. · Members of the Organizing Committee who gave very generously of their time and services in defining the scope of the conference, in selecting the topics to be discussed and in designating the authors and conference participants. · The California Advisory Committee which assisted with the planning and implementation of conference logistics and arrangements. · The authors and discussants who accepted defined writing assignments and who cooperated in developing an integrated symposium. · Conference participants for their review of the essays and their useful critiques in the conference deliberations. · Jack D. Johnson, the initial chairman of the Directorate on Arid Zone Ecosystems, who continued to provide enthusiastic support for this venture as a member of the Organizing Committee. · Robert M. Hagan for his outstanding leadership and effort as chairman of the Directorate and of the conference Organizing Committee, and for continuously infusing all of his associates with the significance of this educational undertaking. · Marcia Kreith for exceptional service as administrative coordinator of the conference, a person who deserves high praise for seeing that all activities were implemented on schedule. · Raymond H. Coppock for providing expert informational services throughout the planning and implementation of the conference.

―x― · Noreen Dowling whose administrative talents and communication skills were helpful in many ways. · The staff of the University of California, Davis, who provided invaluable assistance at various stages of this undertaking, notably Betty Esky of the Department of Land, Air and Water Resources for secretarial services, Marian Cain, Kelly Carner and Paula Sullivan of the Public Service Research and Dissemination Program for administrative and secretarial services, together with Patricia Farid of the Water Resources Center, for assistance in the preparation and publication of this volume. THE EDITORS

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INTRODUCTION— NO SIMPLE SOLUTIONS by Ann F. Scheuring, Ernest A. Engelbert, and Robert M. Hagan We are approaching the end of an era in the West. As with most such transitions, it is a period of some confusion and conflict. The era in question is that of seemingly unlimited western water development. We have begun to realize that there are indeed limits to the water resource base, that we will have to learn to live within them, and that we must come to agreement on priorities for use of water supplies in the future. The subject of this book is whether and how irrigated agriculture in the West will be affected by these new perceptions and changing conditions in water management. Water is the lifeblood of the West as we know it today. Much of the semiarid western landscape has been altered over the past century by human manipulation of scattered natural water supplies. In many locations irrigated farming has replaced native vegetation and dryland ranching, bringing new productivity to the land and improving local economies. With increasingly uncertain outlook for water supplies in the future, however, new adjustments may have to be made within the agricultural sector. Plans for further expansion of irrigation may have to be cancelled and some land now under irrigation may revert to semiarid conditions, unless accommodations to the increasing constraints on water supply can be made. Both competition

for limited resources and changing viewpoints on social utility challenge former assumptions about the "best use" for water. Depending on which groups of citizens stand to lose or gain from change, the viewpoints they express are varied and sometimes contradictory. Where life is comfortable, people are apt to rationalize and seek technical "fixes" in the attempt to maintain the status quo. Others struggle to achieve a greater share of resources and degree of equity by negotiation or legislation. Change is not easy, but in the period of adjustment in water policy which lies inevitably before us, special-interest clashes and philosophic disagreements must be tempered by hope for reasonable and far-sighted action. Water issues in the West encompass such large areas and affect so many millions of people, that

―2― programs and policies must be truly collaborative to be acceptable. "There are no simple solutions—only intelligent choices."

What Is the West? As defined in this volume, the "West" consists of those 17 states west of the 98th meridian, from the Canadian to the Mexican borders. This is half of the United States in size, an immense and varied region, with its own geographic peculiarities, history, and ambiance. The West is no single place: it means different things to different people, depending on where they live—rolling plains; thundering rivers; rocky canyons; windswept salt flats; barren volcanic plateaus; marshy swamps; arid deserts; verdant valleys; forested mountains; ocean surf; shabby towns; comfortable cities; sophisticated metropolises. To describe the West in its physical entirety is difficult, but let us briefly try. The great green checkerboard of the agricultural Midwest gives way very gradually to the drier Great Plains. The Great Plains states include North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, and Texas. Relatively thinly populated, with much distance between towns, these states are largely agricultural and produce huge grain crops. The Great Plains states slope upward to the Rockies. The regular geometry of cultivated square and rectangular fields gradually becomes browner, larger in scale, and irregularly contoured in the transition into the Rocky Mountain states of Montana, Wyoming, Colorado, and New Mexico. In these

states the mountainous backbone of North America trends south-tonorthwest from Mexico to Canada. Only a handful of cities appears in the immense mountainous landscape, and agriculture is limited to river valleys. Spurs and subranges of the Rockies continue west into the states of Idaho, Utah, and Arizona, merging gradually into the Great Western Desert—the high arid plateaus and salt flats of southwestern Idaho, western Utah, all of Nevada, and much of Arizona. In northwestern Arizona the Grand Canyon slashes through the high desert, cut by the Colorado River over eons of geologic time. Much of this four-state area is still relative wasteland, though scattered green settlements dot the occasional waterways.

―3― On their eastern borders the Pacific Coast states of Washington, Oregon, and California are also part of the semiarid western desert, but these states' climate is transformed by the Sierra Nevada and the Coast Ranges, as well as by the Pacific Ocean. Western Washington and Oregon and northern California are moist, mountainous, and thickly forested; rainfall and snowpack can be heavy. South of the Cascades and west of the Sierra, the 400-mile-long Central Valley of California displays a rich and varied agriculture, while most of the state's famous cities cluster along the coast. Southern California is, again, mostly desert except for coastal basins and valleys. Thus the West consists of several distinct major climatic zones, with varied topography, soils, and precipitation. With the exception of relatively humid western Washington and Oregon and northwestern California, however, most of the West is arid or semiarid, registering on average less than 20 inches of rainfall per year. It is a region which characteristically depends on irrigation for its agricultural productivity or is dry-farmed—and where, to meet agriculture's needs, the most intensive water developments in the world have taken place.

History: An Epoch of Development It was the fact of aridity, coupled with the immense distances and rough terrain, that discouraged early settlement of the region. Though Lewis and Clark explored the upper reaches of the West as early as 1805, only a relatively few hardy pioneers pushed through the trials and terrors of wagon train travel in the first half of the 19th century. The California Gold Rush in 1849, however, set off an explosion in population movement, and the following decades saw settlement throughout much of the West.

The Homestead Act of 1862 was intended to aid settlement of the U.S. by offering chunks of the public domain nearly free to anyone who would make a serious effort to develop a farm or ranch. In the semiarid West, however, it was soon learned that 160 acres—the original amount of land allowed for individual homesteads—was hardly sufficient. Subsequently the law was amended; in certain areas a homestead claim could be up to 640 acres, or a square mile, because of the low grazing capacity and limited agricultural possibilities of water-short country. By 1900, aided by the expansion of railroads, most of the West was at least thinly populated. The image of the "Old West" changed as its economy developed from mining and early livestock-grain agriculture to a more diversified base. As mining

―4― became industrialized, prospectors became figures of the past. In such states as Wyoming, Oklahoma, and California, oil was discovered in huge deposits, bringing a new kind of wealth. Water development brought in irrigation, changing farming patterns. The Depression impelled many dustbowl migrants to seek employment in the West. World War II also brought large numbers of people to the West for military reasons, and many of them remained or returned after the war to take advantage of the climate, the lifestyle, and the opportunities they saw. New industries began to populate the western states, particularly entertainment, communications, and aerospace in Southern California and high technology and electronics in other areas. More than a place, more than a history, the West also represents a mindset. In comparison with the humid eastern seaboard and fertile Midwest, the early West was not an easy place to settle. Perhaps it took special kinds of people to move into a raw, often hostile wilderness. Western pioneers were sometimes dreamers, sometimes renegades from polite society; but they saw opportunities for enterprise in a landscape that offered wealth for those who could take advantage of it. Speculators and ambitious settlers recognized chances for development of natural resources through ingenuity and emerging technology. Gold miners in California extracted billions of dollars in gold using extensive flumes for sluicing and hydraulic hoses for blasting away earth from mineral deposits. The Mormons in Utah were among the first to build networks of canals for irrigating farms wrested from the desert. Public policy also encouraged settlement, development, and even exploitation. Where water was in short supply, private efforts at impoundments and canals were supplemented by public funding after the turn of the century. Local water districts brought water consumers together

for development of resources through taxation. Sometimes decades in advance of their construction, grand plans were suggested for state and federal dams on the Missouri, Arkansas, and Pecos rivers of the Great Plains; for the Colorado of the Southwest; for the Columbia of the Northwest; and for the Sacramento and San Joaquin valley watersheds in California. Boulder Dam, later called Hoover, harnessed the Colorado River in 1936, and Bonneville Dam spanned the Columbia in 1937. In Montana, Fort Peck Dam controlled the upper Missouri River in 1940. California's Central Valley Project completed Shasta Dam in 1944; Garrison Dam in North

―5― Dakota was finished in 1960; and the California State Water Project brought additional irrigation and power to California starting with Oroville Dam on the Feather River in 1968. These gigantic dams and canals, pumps and pipelines to store and transfer water, are a symbol of today's West. They stand as monuments to human ambition, in a remarkable blending of engineering and socio-economic vision. Where cattle and sheep and dryland grain were once the agricultural mode, some western states have diversified into row and vegetable crops, orchards, vineyards, and a host of specialty crops. None of this would have been possible without irrigation. In 1977 the 17 western states had 49 million acres of irrigated land, or 85 percent of all irrigated land in the U.S., and accounted for 91 percent of all water used for irrigation in the nation. Massive interbasin water transfers are a way of life in parts of the West. Irrigated agriculture produces a great deal of income. California alone, for example, has led the nation in cash farm receipts for more than 30 consecutive years. The state earned about $14 billion in revenues from agriculture in 1981, or about 10 percent of national gross cash receipts from farming. California produces more than 200 different agricultural commodities, many of them grown nowhere else in the nation and in few other places in the world (almonds, artichokes, Brussels sprouts, nectarines, olives, prunes, walnuts, to name a few). Approximately 30 percent of California's total agricultural revenue is now earned in export markets, accounting for nearly 10 percent of total U.S. agricultural exports in dollar volume. And it is the 8.5 million acres of irrigated California farmland which produces the bulk of California's farm income.

A New Era Why does it now appear that the West is approaching a new era? Resource development over the last century has resulted in a dynamic economy. What signs suggest that this era of development is ending? Western states are still very young historically—Arizona was the last continental state to be created,

in 1914. With the vast open spaces and resources yet remaining in the West, one might think that there are potentially many years of development still ahead. There are, in fact, planned stages of such massive undertakings as the Missouri River Basin Project and California's State Water Project not yet under construction. The physical facts, however, are plain: almost all the potentially good agricultural land close to water supplies has already

―6― been developed. Moreover, most of the readily available water sources of the West have been accessed; certainly all of the relatively inexpensive sources have already been tapped. Few rivers are without dams, and most of the major rivers have whole series of them. Reservoirs, giant and small, dot the western states. In addition, groundwater supplies in some areas are being measurably depleted as ever deeper wells draw up water from aquifers. In some areas land subsidence signals serious sinking of the water table. In certain locales water quality has also become a problem, with increased salinity of supplies or deterioration through chemical and other pollution. Thus even the same quantity of water supply becomes less usable for former purposes. In some cases stream diversions or impoundments have destroyed or severely damaged formerly abundant natural wildlife habitat and fisheries. In addition, economic balances are changing. We have had clear warnings of coming energy shortages. Given our addiction to massive consumption of fossil fuels, energy equations for pumping water will change radically as such fuels begin to run out. Construction and development costs have soared over the decades, and it is likely that even where new dams and storage projects have been considered technically feasible, they may not be affordable. Social viewpoints are also changing. Agriculture may once have been the hub upon which western economies turned, but as areas diversify, competition between uses for water increases. Industry has need for water in manufacturing, for cleansing, and for power; commercial fisheries and forestry require water to sustain their natural base; cities demand water for residential and municipal purposes; and recreationists value such waterrelated amenities as boating, swimming, and sport fishing. Nor is economic competition the whole story. U.S. society has seen the rise of what is termed the conservation ethic, under which the natural environment is valued as much for itself as for its exploitable potential. Some citizens protest what they perceive as the narrow view that a resource has value only insofar as it can be made productive for human purposes. They argue that biologic diversity and aesthetic values must be safeguarded for future generations; that every stream need not be dammed, every acre

planted, every drop of water "used." Thus we find ourselves at a turning point, and it is not clear how rapidly we will change course. We know, however, that our course will change. The question is, to what extent will we choose the direction?

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Issues and Choices At issue in this book is whether irrigated agriculture in the West as we know it today is truly in jeopardy—and whether, after all, it matters. We know some things, and can guess at others: 1) In some areas of the West it has taken a massive public investment to bring surface water onto arid lands which could otherwise not support modern agriculture—and the subsidy continues in the form of reduced water prices for irrigation. 2) In several areas of the West groundwater supplies are being depleted, endangering the future viability of farming communities. 3) Agricultural irrigation now accounts for about 85 percent of developed water put to use in such states as California, but increasing demands for water for other purposes will in some regions of the West cut into agriculture's current supplies. 4) Water quality is deteriorating in some areas, soil quality in others. Salinization, for example, presently affects large acreages. One answer to salination is to build drains and use more water for flushing salts away, but this requires both sufficient water and adequate engineering, and is costly. Another reaction to the problem is simply to abandon the land because it is too expensive to reclaim. 5) The outlook for developing significant new surface water supplies to meet increasing demands is questionable, given limited sites for development, soaring construction costs, and voter skepticism. 6) Certain peripheral effects related to use of water for irrigation (including loss of fish and wildlife, increased erosion, pollution from agricultural chemicals in runoff, etc.) suggest that long-term adjustments in water use may be necessary.

7) Long-range data on climatic cycles indicate that recent decades may have been unusually moist in the West, and that extended periods of drought may lie ahead. Thus even our present estimate of water supplies may be more sanguine than history warrants. Such facts and reasonable guesses would indicate that western agriculture is, if not in jeopardy, slated for some considerable changes in future. It is clear that local circumstances vary considerably, and that different areas will have different problems

―8― and pressures. But overall it seems fair to say that irrigated agriculture in the West may not be totally sustainable under its present arrangements. We may indeed find that the "blooming of the desert" was, in some cases, an exciting but temporary phenomenon. Already in a few places abandoned cropland gives mute testimony to past doomed efforts at cultivation. Does this matter? Is it important that present-day irrigated agriculture in the West be "saved?" Are there, in fact, ways to moderate trends and stave off local crises? The first and second questions are matters of economic and social judgment. Western agriculture contributes significantly to the nation's food and fiber supply, and to the U.S. balance of payments in world markets. Nevertheless, the West is only part of the larger nation; and if one production region should fail, another may take up the slack. According to some observers, the primary U.S. agricultural problem today is over-supply, not insufficiency. But today's balance of supply and demand is not necessarily that of the 21st century—and national and world populations are growing. Usually discussions of the importance of agriculture are couched in economic terms, but a sociological dimension also needs recognition. Part of the ambiance of the West is its farming and ranching base. Deterioration or destruction of that base might alter the very character of the region. Again, this is a matter of judgment: does it matter? Many civilizations as well as regional cultures have come and gone. Is the West in its present condition uniquely worth supporting? Is the way of life in the West—which many have admired—one which ought to be preserved? The third question asks what options may be available to deal with pressures on agricultural water supplies. These options may be divided generally into four categories: technical and scientific innovations; management strategies; institutional arrangements; and modification of lifestyle. These are not mutually exclusive, and may in fact be used in many combinations, depending on water use situations. We rank them here in order from the

local and specific (on-farm practices) to the very broad and general (societal change). Technical and scientific innovations. These may include improved irrigation technologies, better plant breeding for drought resistance, precise monitoring of water needs, systematic groundwater replenishment, and other kinds of water-using and water-conserving techniques. Advances in science and

―9― technology can be a major factor in ameliorating the consequences of water shortages throughout the West. Management strategies. Recent years have shown that agriculture can pursue a variety of management strategies to achieve more efficient water use. These strategies include appropriate use of crops, careful water scheduling and recycling, effective employment of machinery, good economic and financial determinations, and all other aspects of farm decision making involving land and water practices. Institutional arrangements. Realignment and reorganization of existing institutions dealing with water, both public and private, may be helpful in cutting waste and in encouraging collaborative overall efficiency. Building flexibility into institutional arrangements may also help them respond to local needs more effectively. Modification of lifestyle. Economic sustainability may ultimately have to be based on lower economic expectations, both among individuals and in society at large. If nonrenewable resources are being depleted and even renewable resources seem under great pressure, one logical answer to the problem may be for consumers to be satisfied with less consumption. An exploitative tendency can be replaced with a philosophy of stewardship, though this may take years of experience and education. Social equity also demands commitment to reasonable goals by all citizens, not just by some. Underlying any options for action to address water problems are certain basic philosophic principles, all of them related, which can be mentioned here only as questions for public debate in a democratic society: · What balance between economic laissez-faire and institutional regulation is desirable? · What balance between local control and centralized decision-making is

best? · Is incrementalism or long-range planning preferable? Decisions for action (or nonaction) will inevitably reflect answers to these central questions.

An Overview of this Volume This book has been designed to discuss the western water situation from multiple perspectives. Water policy is by its nature complex and must be approached from several points of view. This book therefore attempts to review economic and social

― 10 ― as well as scientific and technical information relevant to the assessment of desirable policy. Each main chapter is accompanied by commentaries which provide additional information or suggest other facets of the subject under discussion. Part I provides an overview of the facts and conditions of water availability in the semiarid West, first from the hydrological perspective and then from institutional and economic perspectives. Chapter 1 gives information on precipitation, streamflows, and important aquifers in the West, and identifies areas where water supplies appear critical. Chapter 2 describes water law and institutions which govern water allocation. This chapter suggests that many western states will have to make some changes in legal and institutional arrangements to achieve greater efficiency in water use and management. Chapter 3 reviews trends in competition for water among economic sectors. Many areas of the West face shifts in water use from one industrial sector to another; this will have significant impact upon local economies, particularly agricultural communities. Part II consists of six chapters describing possible alternatives for satisfying water demands by western agriculture. Chapter 4 explores the alternatives for developing new water supplies to meet increasing demands. It concludes that the opportunities for large scale augmentation of present supplies are limited and that no significant technological breakthroughs are in sight. Chapter 5 examines the possibilities for increasing the efficiency of nonagricultural water use. While some savings in urban-industrial uses can be made, the gains will not be sufficient to cover the impending shortages in agricultural water needs. Chapter 6 describes research on management strategies to cope with increasing soil salinity in semiarid regions. This increasing salinity, the most extensive irrigation-caused problem faced by

western agriculture, will call for a diversity of techniques and controls to improve the situation. Chapters 7, 8, and 9 review current on-farm methods for improving crop management, land use, and irrigation systems. Chapter 7 discusses crop shifts, use of drought-resistant crops, and improved production techniques. Indications are that in the future farmers will have to modify many present cropping patterns to maintain optimum production with declining water supplies. Chapter 8 reports on proven ways to sustain arid-land agriculture through water "harvesting," minimum tillage, snow management, and other practices. An expansion of dry-land agriculture appears inevitable for many areas of the semiarid West.

― 11 ― Chapter 9 treats engineering improvements that can be made in irrigation systems. It concludes that massive changes in conveyance and application systems will provide only a modest increase in net water supply for agriculture. Part III encompasses six chapters that focus upon the economic, social, and environmental impacts of limited water supplies in the West. Chapter 10 looks at the impacts of less water upon regional and local economies. The evidence suggests that while irrigated agriculture will face some retrenchment, the overall regional economic impacts should be gradual and minor. Chapter 11 analyzes the impending decline of irrigated agriculture in the West from the standpoint of the national and international agricultural commodity systems. Using an econometric model, the chapter concludes that, depending upon economic and institutional variables, reduced water supplies will result in only slight food price increases in both the domestic and international markets. Chapter 12 examines the impact of limited water supplies upon business communities in the West. Increasing water prices will result in a more intensive agriculture, with consequent implications for land values, agribusiness enterprises, banking, and other economic sectors. Chapter 13 discusses what will happen to rural communities if irrigated agriculture declines. It predicts considerable unemployment and social suffering unless remedial actions are taken to diversify local economies. Chapter 14 looks at the impact of the changing agricultural base upon urban communities. Serious unemployment problems for cities arising from a ruralurban migration are not expected since the numbers of people affected by a declining western agriculture would be relatively small. Chapter 15 considers the environmental consequences of agricultural land going out of production. Reversion of land to dryland farming or to nonuse may, unless corrective actions are taken, result in wind erosion and damage to fish and wildlife habitats.

Part IV outlines some strategies for maintaining agricultural viability in the West with limited water. Chapter 16 describes some specific technical and management solutions to water problems from the farmer's viewpoint. The chapter shows that farmers can be innovative in adjusting to declining and higher-priced water supplies. Chapter 17 examines how business and financial interests can respond. Emphasis is placed upon the need for more research and development, upon appropriate systems of financing, and upon better cooperation between the business and agricultural sectors. Chapter 18 discusses changes in the system

― 12 ― for the allocation and transfer of water supplies. It calls for the evolution of an economic market system for water rights so that water may move to the geographical areas and sectors of most valued use. Two chapters, 19 and 20, address state and national water policies and practices. The state of Montana's efforts for water resources management are described in Chapter 19, while Chapter 20 chronicles the shift in federal policy to encourage state initiative and the deregulation of water markets. The complexities of government policies and programs for water resources are reflected in both chapters, and the need for intergovernmental cooperation is emphasized. Part V provides an integrative summary of the major problems and findings of the preceding chapters. Subjects are interrelated and placed in perspective. Issues which need to be resolved are identified. The challenges facing western water planners are highlighted. A number of views emerge from this book, although they are not held equally by all authors: 1) There is no immediate national crisis with respect to water for western agriculture. 2) Some regional impacts due to local decreasing water supplies are inevitable, and some local and individual situations could become traumatic. 3) It is difficult to predict when future adverse impacts will become evident because adjustments may still be made. 4) Impacts of declining water supplies may be partly offset by technical and institutional adjustments, some of which are already taking place.

5) Much uncertainty exists because of economic, political, climatic, demographic, and other variables. 6) Assessments of water supply and demand, to some extent circumstantial, may change in the future. 7) Lack of a present crisis does not preclude a future crisis caused by increasing population, growing world food and energy needs, and possible climatic changes. 8) Since the federal role in water policy appears to be decreasing, local and private sector initiative may have to fill in any gaps. 9) Several chapters suggest that allocation and transfer of water might be in some cases appropriately implemented through the marketplace.

― 13 ― These varied views emerging from the chapters suggest how complex and challenging is the subject of water in the West. Future studies and decisions, as our authors remind us, must truly be both interdisciplinary and collaborative.

The Future of Water in the West Why Planning Is Difficult The summary chapter of this volume suggests several factors which make rational overall water planning difficult: (1) territorialism and ownership disputes; (2) uncertainty about key facts; (3) political evolution; (4) an ongoing shift in ethos; and (5) a certain apathy, or at least a tendency toward inaction, without a crisis for motivation. All of these are significant constraints on our ability to plan for the future. Few of us would disagree, however, that some kind of planning for the future is prudent, if not without risks. It is clear that some areas of the West will inevitably experience problems as water supplies become increasingly strained to their limits. Several areas are already identified as being in "critical overdraft," i.e., the condition in which water supplies are being depleted faster than they can be replaced. There is not much doubt that these areas will likely experience serious economic discomfort as water becomes more scarce and dear. The rumblings of these dislocations are already being felt.

We can make certain predictions on what may happen in farming communities where overdraft trends continue. There will be more financial risk and failure for farmers; there will be changes in crops and in irrigation methods; some acreage may be phased out of production. Land values may decline, the tax base may shrink, farm-related businesses may suffer, communities may decline as the economic base erodes. Water availability will certainly influence the distribution of income and wealth between areas. There will be transfer of wealth out of water-short areas into those with more abundant supplies; the decline of income in one area will be picked up elsewhere. Agriculture is nevertheless an adaptive system. It can adjust in a variety of ways to limited water; or water can be transferred among agricultural regions. Such adjustments need not be disastrous, and some of them are already currently taking place. To encourage rational conservation activities and to alleviate widespread impacts from water shortages, it behooves water planners on various levels of government to take as clear a look at water planning for the future as is possible.

― 14 ― Much of our uncertainty as to prediction stems from the nature of certain variables—climate, energy, population, and political events, to name only a few. In many ways our crystal ball is cloudy, and must remain so. With regard to climate, for example, the commentary to Chapter 1 suggests that the West may be experiencing an unusually moist few decades in the 20th century, compared to other eras recorded in existing western tree ring data. If climate altered substantially over a period of years—which is entirely possible—our current estimates of surface and groundwater supplies would have to be radically revised. Current international markets also figure prominently into the U.S. agricultural picture. Disruption of these markets through political events or economic upheavals could change supply-demand equations drastically, and thus incentives for agricultural production. Energy, as an essential component in the pumping of water, also remains an uncertain variable, with the only sure prediction being that prices for fossil fuels will go up. But how fast? How far? Population trends are another question mark. U.S. and world population is sure to expand in the decades ahead, increasing food needs; but we don't know the magnitude of population expansion to expect, nor do we know how other world regions will deal with the needs of their peoples. Dire warnings have been made about world population trends and future food needs, but

even the experts disagree. It is difficult to make long-range plans when there are so many admitted uncertainties, but we know that we should at least be prepared to cope rationally with emerging possibilities. Western water planners will deal best with an uncertain future if they are able to direct their activities along reasonably logical lines.

Needs for Action Many of the chapters in this volume explicitly or implicitly recommend certain kinds of action to be taken on a number of fronts. Briefly, we condense and list these recommendations here: · Research and information gathering on consumptive and environmental water needs, including more agreement on methodologies of analysis to be employed. · Widespread adoption of efficient and cost-effective water management and conservation techniques, including conjunctive use of ground and surface waters in basins.

― 15 ― · Investigation of feasible new water developments in certain specific locations. · More availability of capital for long-range water management goals, at both local and regional levels. · Appropriate provision for environmental and social needs in water management and use. · More innovation in interorganizational planning, particularly at the local level. · Removal of institutional barriers to economic freedom in decision making. · More collaboration between federal government and states in management of projects and coordination of policies.

· Better cooperation and more compromise among interest groups representing water users. These calls for action seem to fall into two general categories: the gathering of more information and knowledge on such matters as environmental interrelationships, technical and scientific innovations, management possibilities, and economic systems; and the building of more flexibility and cooperation into institutions and organizations concerned with water. Those who live in the western United States have both the opportunity and the challenge to show other water-deficient areas of the world how limited water resources can be managed not only for regional well being, but for the ultimate benefit of mankind.

A New Stage of History Unlike any other era in human history, we of the later 20th century have the capacity to look at our globe as a whole. The astronauts who first looked back on the Earth from space were struck with both the beauty of the planet and its vulnerability. Suddenly we know that the Earth is fragile; we have begun to realize that there are limits to natural resources, and to our human activities. Our era is crucially different from those which have gone before. We have greater scientific and technological power—both constructive and destructive —to change our surroundings. We have more knowledge at our fingertips, more ability to gather new information, more power to integrate and transmit it. We realize, and can learn from, mistakes of the past. Our electorate is less likely to foot costly projects, more likely to question motives and intent, and more likely to recognize their own interests. As we grapple with the problems of the present, we have a sense for the complexities inherent in our choices. Perhaps it is that consciousness of complexity which will allow us to become a more mature society, no longer committed to simple

― 16 ― solutions, but able to take a wise and balanced view of the resources of our planet—of the West—not only as they will serve us in the short run, but as they will sustain us over time.

― 17 ―

PART I— WATER AVAILABILITY FOR AGRICULTURE IN THE SEMIARID WEST Chapter 1— Physical Limitations of Water Resources by John Bredehoeft

Abstract In considering the concept of the hydrologic cycle today one must take into account man's influence as an integral part of the functioning of the cycle. Except for the mining of groundwater, the same quantity of water is, on the average, in transit in the hydrologic cycle. Groundwater mining is extensive, especially in Arizona and the High Plains of Texas and New Mexico. Groundwater, however, is a one-time supply; to the extent that we mine it, we are faced with a shortage in the future. Both urban movement to the Southwest and energy development compete with agriculture for the available supply, especially in the areas of critical water supply, southern California and Arizona. Competition is present throughout the semiarid West; anywhere water is fully appropriated, increased urban and industrial supplies must come from agriculture. There seems little doubt that as we approach the limits of available water supply there will be increasing competition for water. In a classic economic sense increased competition implies a shortage.

The water supply of the West is nearly fully utilized. It is difficult to foresee major construction projects which will add significantly to the currently available supply. Several critical areas are now heavily dependent upon mining groundwater, a supply which will be depleted at some point in the future. Urban and energy developments, especially in the Southwest, are competing with agriculture for the available water. This competition will undoubtedly intensify, which poses two major issues for society: 1) How will society, at local, state, and regional levels, cope with the increased competition for water? 2) To what extent can the nation forego irrigated agriculture in the West

without significantly decreasing its agricultural output?

― 18 ― It is not the intent of this chapter to address these issues; however, we will attempt to provide an overview of the current availability of water.

The Hydrologic Cycle Traditionally, when considering the problems of water resources we hydrologists have been prone to think in terms of virgin or natural streamflow. However, it has become increasingly obvious that natural flow is a relict of the distant past. Man has impacted the water resources so dramatically, especially in the arid and semiarid West, that natural flow does not exist except perhaps in the most remote areas. We must recognize that man's activities are today an integral and inseparable part of the hydrologic cycle. Our current understanding of the hydrologic cycle can be described in a paradigm suggested by Matalas, Landwehr, and Wolman. The three tenets of the active paradigm are: i) human activity is inseparable from the natural system; ii) quality is no less a concern than quantity of the water mass as it is distributed and moves through the cycle; iii) the quantity of the water mass affects and is affected by the quality of the water.[1] If we accept the active paradigm as best characterizing our concept of the hydrologic cycle, then it is impossible to look at the physical and chemical limitations on water resources without looking at man's activities.

Available Water Precipitation ultimately is the source of water resources. The average annual precipitation for the United States is depicted in Figure 1.1. That precipitation translates into runoff. West of the 100th meridian much of the land is characterized by less than one inch of runoff. The areas of abundant runoff in the West are easily identified in Figure 1.2. The relative magnitude of the average streamflow of the large rivers in the U.S. is shown in Figure 1.3. The major rivers of interest in the western states are the Columbia, the

Colorado, the Sacramento, the Missouri, and

― 19 ―

Figure 1.1 Average Annual U.S. Precipitation, 1931-1960 Source: U.S. Council on Environmental Quality, Environmental Trends, Washington, D.C., 1981, p. 346.

― 20 ―

Figure 1.2 Average Annual U.S. Runoff Source: Rickert, D.G., W.J. Ulman, and E.R. Hampton, Synthetic Fuels Development—Earth Sciences Considerations, U.S. Geologic Survey, 1979, p.45.

― 21 ―

Figure 1.3 Average U.S. Streamflow, 1941-1970 Source: U.S. Water Resources Council, Essentials of Ground Water Hydrology Pertinent to Water Resources Planning, Bulletin 16, revised 1979, p.48.

their tributaries. Future large-scale surface water diversions must almost certainly come from these river systems. Runoff comes largely from the mountains in the spring as snowmelt. The typical seasonal variation is illustrated by the long-term average monthly runoff for the Clarks Fork of the Yellowstone River near Belfrey, Montana, Figure 1.4. Storage of water, either in surface reservoirs or in aquifers, improves the timing between supply and demand, especially the seasonal demand for agriculture.

― 22 ―

Figure 1.4 Average Monthly Runoff, Clarks Fork of Yellowstone River Source: Rickert et al. Groundwater forms an additional resource. The important aquifers of the western United States are shown in Figure 1.5.

Depletion of Water Given our picture of surface and groundwater, how much is utilized? Relative water depletion is depicted in Figure 1.6. Depletion is defined as "the total consumptive use plus any water exported from each basin, divided by the total supply". Groundwater mining has been excluded from the long-term supply. This is perhaps the most important single illustration in this paper. Several critical areas show up on the map of depletion: 1) Most of the lower Colorado River basin, southern California, and most of Nevada, where the depletion

― 23 ―

Figure 1.5 Extensive Aquifers of the U.S. Source: U.S. Water Resources Council, 1979.

― 24 ―

Figure 1.6 Relative Water Depletion in the U.S. Source: Rickert et al.

― 25 ― exceeds 100 percent. The differences are made up from mining groundwater. 2) South-central California, including the San Joaquin and Owens Valleys, where the depletion exceeds 75 percent. 3) The High Plains of Colorado and west Texas, where the depletion exceeds 75 percent. 4) Much of New Mexico, where the depletion exceeds 75 percent. The depletion map is somewhat misleading, since instream flow requirements are not accounted for, and they are important constraints on water availability. Groundwater constitutes an important additional source of water. Groundwater withdrawals are shown in Figure 1.7. California and Texas are the two largest users of groundwater, accounting for 37 percent of the total withdrawn nationwide, closely followed by Nebraska, Idaho, Kansas, and

Arizona, which together account for an additional 26 percent of the total. These six states account for almost two-thirds of the groundwater withdrawn in the United States. The relative importance of groundwater as a source of water in the semiarid West is depicted in Figure 1.8. Groundwater constitutes the major source of water, exceeding approximately 50 percent in much of the High Plains, a large portion of Arizona, and parts of California. Much of the groundwater withdrawn is being mined. The Second National Water Assessment of the U.S. Water Resources Council[2] identified areas of groundwater overdraft—"mining" in my terminology—as shown in Figure 1.9. The principal areas of overdraft identified west of the 100th meridian are (1) the high plains of Texas, New Mexico, Colorado, Oklahoma, and Kansas, and (2) large areas of Arizona. Moderate overdrafts occur over much of the area west of the 100th meridian.

Water Use How is the water used? Figure 1.10 is a graph of water withdrawals for the period 1950 through 1975 for the entire U.S. The

― 26 ―

Figure 1.7 U.S. Groundwater Withdrawals, 1975 (million gallons per day) Source: U.S. Water Resources Council, 1979.

― 27 ―

Figure 1.8 U.S. Groundwater Withdrawals, 1975 (percent of fresh water used from groundwater sources) Source: CEQ, 1981.

― 28 ―

Figure 1.9 U.S. Groundwater Overdraft Source: CEQ, 1981.

― 29 ―

Figure 1.10 U.S. Water Withdrawals, by Use, 1950-1975 Source: CEQ, 1981. largest withdrawals are for power plant cooling and irrigation. Consumptive use, on the other hand, presents a very different picture. Figure 1.11 shows nationwide water consumption. Irrigation accounts for by far the largest fraction of consumption. In the western states irrigation accounts for more than 90 percent of the consumptive use. Groundwater use is also interesting; the growth in groundwater withdrawal over the last 25 years has been almost exclusively for irrigation, as is shown in Figure 1.12. In 1977 42 million acres were irrigated, for which the consumption was approximately 82 billion gallons a day (92 million acre-feet per year). Something approaching one third to one half of that water came from groundwater, much of which was mined, as Figure 1.9 indicates.

― 30 ―

Figure 1.11 U.S. Water Consumption by Use, 1950-1975 Source: CEQ, 1981.

Figure 1.12 U.S. Groundwater Use, 1950-1975

― 31 ― Eighty-four percent of the fresh water consumed in the coterminous United States is consumed in the 17 western states; most is utilized for agriculture. The acreages irrigated in the 17 western states are given in Table 1.1. California accounts for 23 percent of the total acreage; together, Texas and California account for 42 percent of the total.

Table 1.1 Irrigated Acreage in the 17 Western States, 1975 State

Acreage (millions)

California

8.7

Texas

6.9

Nebraska

3.3

Colorado

2.9

Idaho

2.9

Montana

1.9

Kansas

1.6

Oregon

1.6

Wyoming

1.5

Arizona

1.2

Washington

1.2

Utah

1.1

New Mexico

0.9

Nevada

0.8

Oklahoma

0.5

South Dakota

0.2

North Dakota

0.1

Total

37.3

Source: U.S. Soil Conservation Service, Crop Consumptive Irrigation

Requirements and Irrigation Efficiency Coefficients for the United States, U.S. Department of Agriculture, 1976, p. 24.

― 32 ― Looking at statistics for the nation as a whole may appear to be somewhat misleading. However, since the 17 western states dominate the consumptive use, consuming 84 percent, the statistics for the nation are strongly influenced by the West, where agriculture is the primary consumer of water.

The Lower Colorado Basin In any overview of the water resources of the semiarid West, the lower Colorado River basin and southern California stand out as the most critical areas for water. Another look at the depletion map, Figure 1.6, indicates that the water supply is more than 100 percent depleted in these areas. This is substantiated by the overdraft of groundwater shown in Figure 1.9. The Colorado River is the principal long-term source of water for much of this area. Stockton and Jacoby,[3] utilizing tree-ring data, reconstructed Colorado River streamflow back to 1512. Using this record they estimated the mean annual flow at 13.5 million acre-feet. This is approximately 2 million acre-feet less than anticipated when the water rights were divided in the 1922 Colorado River Compact. Unfortunately, the 1922 Compact was based on records of flow during a series of unusually wet years from 1906 to 1920. The availability of water from the Colorado is further complicated by a number of Indian claims upon the river which are as yet unresolved. A synthesized record of the flow of the Colorado River below all major diversions, in Figure 1.13, portrays the outflow of the river into the Gulf of California. The downward trend of the residual flow, which is caused by an increasing use of water from the Colorado River, is evident. Usage by Mexico as well as by the United States is reflected in the residuals. (Under the terms of a treaty between the United States and Mexico in 1944, supplemented by various "minutes" and negotiations, Mexico is allotted an annual quantity of 1.5 million acre-feet.) Diversions from the Colorado began considerably before 1900. However, prior to that year, annual net diversions generally were less than 1.0 million acre-feet. The residual flows during 1935-39 were unusually low, largely because of the initial filling of Lake Mead. Low flows from 1960 to 1978 reflect nearly complete use of the river. In 1979 and 1980, major floods in

the Lower Colorado River basin downstream from the principal reservoirs resulted in larger outflows.

― 33 ―

Figure 1.13 Annual Flow of Colorado River Above All Major Diversions, 1910-1980 Clearly all the water in the Colorado is currently utilized. The consumptive use within the basin is compared with entitlements from the river in Figure 1.14. The large consumptive use in Arizona is made up in part by groundwater mining. The water in the Colorado is also plagued by an increasing load of dissolved salts. This load comes from a number of natural sources and from sources which are the result of man's actions. Approximately one third of the total salt load is the result of irrigation. Another 10 percent or so comes from Flaming Gorge Reservoir and from Lake Mead, where salts are being leached from geologic deposits inundated by the reservoirs. Figure 1.15 attempts to summarize both the concentration of dissolved solids as well as the total salt load.

― 34 ―

Figure 1.14 Consumptive Uses and Losses of Water in the Colorado River System, 1971-1975 Averages Water is in short supply in the Lower Colorado River basin. Population statistics indicate a growth in urbanization both in Arizona and southern California. If urban growth is to continue, there will undoubtedly be pressure to shift water away from agricultural use.

― 35 ―

Figure 1.15

Salt Load in the Colorado River, 1941-1978 Averages

Alternatives for Additional Water Supplies A number of alternatives have been discussed for increasing the water supply. These are categorized for the purpose of discussion into: (1) increased surface storage; (2) increased groundwater development; (3) more efficiency of water utilization; and (4) large-scale interbasin transfers of water.

Increased Surface Storage Surface storage is the traditional method of providing additional available water. Additional reservoir sites exist in some parts of the western states. Langbein[4] has reviewed historic trends in reservoir development in the U.S. Table 1.2, taken

― 36 ―

Table 1.2 Reservoir Capacity in Some Major River Basins of the United States Region or Basin

Date

Total Usable Capacity (existing plus potential, million acrefeet)

Drainage Area (1000 sq.mi.)

Unit Capacity (acre-feet per sq.mi.)

North Atlantic Region

1966

47.9

173

280

Potomac River

1963

3.9

14

275

Colorado River

1946

102

250

400

Missouri

1969

137

500

270

River Southeast Region

1963

26

88

300

Columbia River

1946

52

220

235

Source: W.B. Langbein, Dams, Reservoirs and Withdrawals for Water Supply—Historic Trends.

from Langbein, shows the reservoir capacity currently available in a number of the major river basins of the country. Langbein has suggested that a unit capacity of approximately 400 acre-feet of storage per square mile of drainage area represents a potential limit for reservoir development; the Colorado has a potential unit capacity of 400 acre-feet per square mile. Langbein also plotted the historic trend of reservoir capacity; this plot is shown in Figure 1.16. The growth in capacity for all purposes and for withdrawal has flattened out since 1960. The question is whether this reduction in reservoir construction will continue, or if it is simply an aberration in long-term growth curve.

― 37 ―

Figure 1.16

Usable Major Reservoir Capacity in the U.S. since 1920 Source: Langbein, 1982. Our assessment is that surface reservoirs will continue to be increasingly difficult to develop. Recent legislation such as the National Environmental Protection Act (NEPA) makes it easier for environmental groups to voice their interests. Every major new reservoir project seems likely to receive some resistance from opposing groups. Major conflicts will, in many instances, be settled politically. In arid regions such as the lower Colorado River basin, where water is particularly critical, additional reservoirs may evaporate as much or more water as is made available, thereby further concentrating the dissolved salts. Increasing surface storage in the lower Colorado is a losing proposition.

― 38 ―

Increased Groundwater Development Groundwater is already heavily utilized, as has been pointed out, much of its development resulting in mining of water. The increased costs of pumping imposed by increased energy costs have reduced groundwater pumping, especially in areas such as Arizona. The one area with apparent potential for a major increase in groundwater development is Nebraska. Table 1.3 is a compilation of the water in storage in the Ogallala Aquifer, the result of an ongoing U.S. Geological Survey study of the system. Approximately two thirds of the water in storage is in Nebraska, an enormous reserve of groundwater. Only in Texas and New Mexico has more than 10 percent of the water initially in storage been depleted. The depletion statistics may be somewhat misleading, since it is economically impractical to remove all the water initially in storage; perhaps 50 to 70 percent is a reasonable estimate of what might be removed under favorable economic conditions. These data indicate that only a small percentage of the water in the Ogallala has been removed. Obviously an enormous quantity of groundwater is still present for development in Nebraska.

More Effective Water Utilization A number of measures have been suggested to effect better utilization of water available. Among these, increased irrigation efficiency, weather modification, reuse of wastewater, conjunctive use of groundwater, desalination, and increased use of saline water have been considered.

Increased efficiency of irrigation has obvious advantages. But a major nagging question is: what happens to the salts in the system when one increases the efficiency? A study of a reach of the Arkansas[5] suggested that following an initial two-to-three-year period after increasing irrigation efficiency, groundwater in the shallow aquifer along the Arkansas River would become more saline. This increase in salinity of the groundwater would increase the salinity of the flow in the river. Pillsbury,[6] in an article in Scientific American entitled "The Salinity of Rivers", argues that salt buildup is a major problem for all irrigation projects. His thesis is that sufficient water must be applied to continually remove salt from the soils. Salt buildup seems to pose some limit on possibilities for increasing irrigation efficiency.

― 39 ―

Table 1.3 Water Supplies and Depletion in the Ogallala Aquifer Water in Storage Percent (1980) Depletion (acre-feet) (predevelopment to 1980) Colorado

112 (x 106 )

5

Kansas

300

8

Nebraska

2100

less than 1

New Mexico

48

16

Oklahoma

92

7

South Dakota

105

less than 1

Texas

375

23

Wyoming

138

less than 1

3270 (x 106 ) Source: Luckey, R.R., E.D. Gutentag, and J.B. Weeks, Water Level and Saturated-Thickness Changes, Predevelopment to 1980, in the High Plains Aquifer in Part of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas and Wyoming, Hydro. Invest. Atlas, U.S. Geological Survey, 1981.

In such systems as the South Platte, or the Arkansas in Colorado, or the lower Colorado, most of the water goes to support beneficial transpiration. It seems questionable that increased efficiency can materially add to the useful supply. Weather modification has received considerable attention. The data, although not totally conclusive, suggest that cloud seeding could increase precipitation locally, with a 10 percent increase in supply possible. The question remains as to what happens downwind—does cloud seeding reduce rainfall? This issue remains to be settled. However, it appears that some local increase in available supply is possible from weather modification.

― 40 ― Reuse of wastewater is another possible source of water. Reuse is already practiced in a number of places. In irrigation, reuse occurs through return flow, which replenishes the streamflow. Municipal wastes have been purchased in such areas as Phoenix, Arizona, for utilization in irrigation. The city of Irvine, California, reuses all of its wastewater, mostly for municipal irrigation. Major metropolitan areas along the coast continue to discharge some wastes to the sea. Some of this water could be reused beneficially. However, the costs of cleaning it up may be such as to preclude it for use in agricultural irrigation. The shallow aquifers in the earth provide an enormous fresh water reservoir. Many of these are already utilized extensively as active storage reservoirs. The conjunctive water use developments along the Platte, the Arkansas, the Rio Grande, and the Snake rivers are classic examples of utilization of the groundwater system as a storage reservoir. In certain areas such as the southern San Joaquin Valley in California,

groundwater reservoirs can be utilized to store water in periods of abundance. Already a number of such developments are well established elsewhere in California, particularly in Orange County and the Santa Clara Valley. The groundwater aquifer has obvious advantages for storage as only small surface areas are affected, evapotranspiration is greatly reduced, and in many places the aquifer serves as an excellent filter for the water. On the other hand, aquifer storage has the disadvantage that it is sometimes expensive to recharge groundwater, especially if one has to utilize wells. How much impact conjunctive use will have in the overall water management in the West is difficult to forecast at this time. The cost of desalinating water makes it too expensive, in most instances, for agriculture. However, the use of desalination for municipal and industrial use may reduce the competition for water currently utilized in agriculture. Saline water can also be utilized for industrial purposes such as cooling, and for special purposes such as slurrying coal. There is abundant saline groundwater over much of the West, and use of these resources could reduce the competition for water. How effective more efficient water utilization measures will be in making water available is anyone's guess. If collectively they could make available 10 percent of the water currently used in agriculture, this would approximately equal all of the other consumptive uses. Ten percent may be an achievable goal.

― 41 ―

Large-Scale Interbasin Transfers of Water Large-scale interbasin transfers, particularly to the lower Colorado River basin, have been proposed as a source of water for some time. The major interbasin transfers are shown in Figure 1.17. The two really significant transfers occur in the Colorado basin and in California. By far the largest of these transfers occurs in California. Traditionally, the states have primacy with respect to utilization of water. Large-scale interbasin transfers cannot take place without a change in state primacy. As water is perceived to be a critical commodity, state primacy will be harder and harder to change. We are pessimistic that this policy can be changed significantly to allow further large interbasin transfers between states. In fact the magnitude of the transfers in California has only been possible, in our judgment, because they occurred within a single state. Interbasin transfer continues to be a sensitive issue even in California, as witnessed by the 1982 referendum over the Peripheral Canal.

It seems problematical that major quantities of water are available for interbasin transfer. For example, Whittlesey and Gibbs,[7] who reviewed the utilization of water in the Columbia for hydropower, concluded that water for irrigation in central Washington costs the general public $150 per acre per year in increased energy costs. This cost comes from lost hydropower downstream and from large quantities of energy to supply supplemental irrigation water which is provided irrigators at very low rates. Under such circumstances it seems highly unlikely that Washington would allow additional water to be diverted for irrigation within the state, and certainly it would fight a major interbasin transfer to another state. Similar situations exist in other western states which, at first glance, appear to have "surplus" fresh water.

Conclusions It is increasingly difficult to effect major structural changes which would provide large quantities of water to those areas where water is in critical supply—southern California, Arizona, and the High Plains of Texas and New Mexico. Outside California, large interbasin transfers must face the issue of state primacy, a particularly difficult issue to overcome.

― 42 ―

Figure 1.17 Major Interbasin Water Transfers in the Western U.S. Source: Modified from Geraughty, J.J., D.W. Miller, F. Van Der Leeden, and F.L. Troise, Water Atlas of the United States, Water Information Center, Port Washington, N.Y., 1973.

― 43 ― One must turn to other measures to utilize more effectively the water that is currently available. Increased efficiency, weather modification, reuse, and conjunctive use, while perhaps not dramatic, have the potential to make better utilization of the available water supply. If collectively these measures could make available 10 percent of the water currently consumed by agriculture, that quantity would approximately equal the total of all other consumption in the West. On the average, the quantity of water in transport in the hydrologic cycle remains unchanged. Except for the fact that we are mining groundwater, no less water is available than heretofore. The fact that we are approaching the limit of the water which can be developed means that there is, and will continue to be, ever-increasing competition for that water. Increased competition implies a higher value for the commodity. While as a society we rarely make large-scale water decisions purely on economic grounds, higher value also implies a higher price. Thus, in the context of increased competition, we have a shortage, at least of inexpensive water. A number of areas in the West depend heavily upon groundwater for their supply. The areas of largest overdraft of groundwater are Arizona and the High Plains of Texas and New Mexico. Much of this water is a one-time supply, obtained by a "mining" operation. Although that is not necessarily bad, the supply is finite, and at some point, perhaps in the distant future, will be gone. Arizona has recently moved to strengthen its groundwater law to protect the resource. The drought of the mid-70s in California motivated farmers to drill many new wells to tide themselves through a period of shortage. Now that the wells are drilled, they continue to be pumped, demonstrating that additional supplies of surface water do not always ease the overdraft of groundwater. In many instances, new supplies bring more land into production. To the extent that we are mining groundwater, we are running out of water. The one bright spot in the water picture in the West is Nebraska, where a huge supply of groundwater is present in the aquifer. The figures on the Ogallala Aquifer in Nebraska suggest that this is probably the largest virtually untapped supply of water present in the 17 western states. There can be little doubt that we are entering an era of continually increasing competition for water. In the Southwest, where water shortage threatens most critically, increasing urbanization and increasing energy development both compete

― 44 ―

with agriculture, now the largest water consumer. Steve Reynolds, State Engineer of New Mexico, aptly states the current water situation when he says, "Water flows uphill toward money." To what extent agriculture in the West can accommodate the competition is the issue.

Discussion: Harold C. Fritts I see no significant weakness in Bredehoeft's lucid and concise discussion except that his projections are based upon relatively short hydrologic records. More specifically, paleoclimatic data indicate that worldwide climate changes occurred around the turn of the century—measurements such as Bredehoeft has used, which are confined to the 20th century, are likely to be biased by these changes. I have used tree-ring widths as proxy climate records (substitutes for instrumented data) to estimate the magnitude of this bias. The ring widths of approximately 1000 trees from sites throughout the West were calibrated with the 20th-century instrumented climatic record throughout the United States. The

― 45 ― calibration equation was then applied to past ring-width growth to estimate past variations in climate.[1] The estimates of climate were then verified with independent instrumented data[1], [2] available prior to the time period used for calibration. Finally, optimal reconstructions were selected based upon the best calibration and verification statistics.

When these procedures are applied to California precipitation[3] (Figure 1.18), pre-20th century precipitation is reconstructed to be below the 20th century mean; when a line is drawn through the plot, long periods of extended drought are evident. Figure 1.19a shows another analysis[4] in which the means for 1901-1970 temperature and annual precipitation in 11 North American regions were compared to the reconstructed means for 1602-1900. The 20th century was slightly cooler than the 17th-19th centuries for five regions in the West, and warmer for the remaining regions. It was 19 percent wetter in California (Region 2), above average in four additional southwestern regions, and dryer elsewhere. Thus one can see that when expectations for precipitation are based solely on this century they would overestimate the long-term expectations for

moisture because of recent anomalous trends in precipitation, particularly in California. Similarly, temperature projections would underestimate conditions west of the Rockies and overestimate them east of the Rockies. Figure 1.19b shows the standard deviations of the reconstructions in the West for the 20th century, compared to the standard deviations for three prior centuries. They indicate a lower variability in 20th-century climate, especially in the amount of precipitation. In addition, reconstructions of surface pressure[4] suggest that coastal storms became more southerly displaced around the turn of the century, bringing higher moisture into California and the Southwest during winter. These storms appear to have traveled on the average in a northeast direction through the Great Lakes. The resulting southerly air flow brought less moisture and warmer temperatures to the eastern portions of the country. Prior to the 20th century storms apparently entered the country more often over the Pacific Northwest, passed over the Rockies, and traveled eastward or southeastward, bringing colder temperatures and more moisture to the East. However, this pattern was more variable, more severe storms were reported in the East,[5] and plains droughts occurred that were as severe, if not more severe, than those in the 1930s.[6]

― 46 ―

Figure 1.18 Average Annual Precipitation for 18 California Stations Reconstructed from 5 2 Western Tree-ring Chronologies Dots represent eight-year weighted averages used to smooth out the annual values. The horizontal line corresponds to the 1901-1961 me an value.

― 47 ―

Figure 1.19 Differences in Climate between the 20th Century and Three Prior Centuries A veraged within 11 Different Regions in North America Figure 1.19a shows the change in means for 1901-1970 comp ared to 1602-1900. Figure 1.19b shows the percent change in standard deviation for 1901-1961 compared to 1602-1900. The upper value in each case is for the reconstructed annual temperature in degrees Ce ntigrade; the lower value is for the reconstructed annual precipitation, in percent.

― 48 ― Stockton and Boggess[7] point out that the consequences of a dry and warm climatic change would be greatest in many areas of the arid Southwest, especially in the Lower Colorado, Missouri Arkansas-White-Red, and Texas Gulf, where groundwater is already extensively used. Two primary future climatic projections have been made by climatologists today.[8] The most popular is that the climate is likely to warm, due to the burning of fossil fuel and an increase of atmospheric CO/d/s-22/s+2/u. The second is that the climate was anomalous for the first half of the 20th century and that it is now likely to revert to the state of prior centuries. In either projection, climate in the semiarid West is likely to be drier, perhaps warmer, and more variable. This would indicate that the existing projections of water resources for the West based on the 20th-century hydrologic record are in all likelihood overestimates of what the water resources may be in the future.

Acknowledgement The research reported here was supported in part by NSF Grant ATM7522378 Climate Variability, Climate Dynamics Program and by the California Department of Water Resources, Agreement No. B53367.

― 49 ―

Discussion: Parry D. Harrison Mr. Bredehoeft presents a rather gloomy picture of the water supplies in the West. Although much of what he says is correct, some of it tends to be a little misleading. I do not fully agree that the water supply of the West is nearly fully utilized. Some river basins like the Colorado could be said to be fully utilized. However, an example of underdeveloped water supply is the Columbia River at The Dalles, with an average flow of over 140 million acre-feet per year; and the Willamette River at Portland averages over 23 million acre-feet per year. I could name at least ten other rivers that discharge between 3 and 15 million acre-feet per year. While it is true that not all of these vast water supplies can be utilized and storage projects are very difficult to construct, many worthwhile storage projects have yet to be constructed. The problem with most of these rivers is that they are far from the heavy demand areas of California and the Southwest. Runoff Predictions. A most difficult problem, and yet a paramount need, is accurate prediction of streamflows for the next six months, year, two years, and five years. Much has been written about the hydrologic cycle, the correlation of precipitation and runoff with sunspots, wind patterns, volcanic activity, effect of air pollution on weather, and effect on weather of atomic explosions. Nevertheless, the ability to predict precipitation and hence runoff with any degree of accuracy has not been demonstrated. The theory has been that the key lies in history; hence, studies of tree ring data, runoff records, stochastic analysis with the aid of computers—and we are still a long way from an acceptable solution. Irrigation. Somewhere between 30 and 75 percent of water diverted for irrigation is a direct depletion and is consumed by evapotranspiration. The remainder either percolates into the ground and becomes part of the groundwater resource or returns to the stream and becomes available for reuse. Return flow usually is of poorer quality than the source. Many

significant groundwater resources have been the result of or enhanced by irrigation. (Examples: Columbia basin in central Washington, Snake Plain aquifer in south-central Idaho, and the Sacramento and San Joaquin valleys in California). Groundwater. Groundwater pumping from an aquifer that is being mined is a depletion of that resource, whatever its use. There may be some reuse or secondary use of the water pumped;

― 50 ― but unless it is reinjected, groundwater that is being mined is not a renewable resource. When it is used up, it is gone. In contrast, streams provide a renewable supply which comes every year, with some fluctuations depending on the weather. Some things can be done to enhance or prolong the life of groundwater resources. These may include (1) artificial recharge: this may be feasible if there is an available resource; (2) limitation or restriction of groundwater pumping; and (3) efficient use of available supplies. Competition for Water. Severe competition for limited water supplies in some areas may make it necessary to choose between irrigation, streamflows for fish, or domestic needs. Abundant and cheap water supplies enhance the quality of life in the West, but in the future some locations may not be able to enjoy them. Most countries do not have the luxury of abundant, high quality water supplies to the extent that we do in the United States and Canada. In the past cities have had to restrict the watering of lawns or filling of swimming pools to ensure adequate supplies for drinking, washing, and fire protection. Many of those vying for control of water supplies have a single-track approach. Some typical comments have been: "My need is paramount." "Irrigation provides food; do you want to watch the fish swim upstream or would you rather eat?" "Fish have been nearly eliminated by diversions and pollution for nearly 100 years; this has to be rectified now!" "Recreation needs are increasing by leaps and bounds; waterbased recreation must be given a high priority." "Water is needed for power production. Power is the basis for our high standard of living. It means jobs!"

Narrow, unyielding approaches make it all the more difficult to find solutions to water supply problems facing the West. The competition is becoming keener every year. Cool heads and clear vision are needed to make good decisions that will influence the quality of the western lifestyle for years to come.

― 51 ―

Chapter 2— Legal-Institutional Limitations on Water Use by Gary Weatherford and Helen Ingram

Abstract For irrigated agriculture, water must be available not only physically but institutionally. Laws, customs, politics, and groups determine whether irrigated agriculture is favored or disfavored in the competitive arena of water management. The fourfold thesis of this paper is: (1) water reallocation and management is gradually replacing water development in the western U.S.; (2) irrigated agriculture's favored legal-political position is declining, but only marginally; (3) change in the relative position of agriculture is likely to continue to be incremental, but more innovative change caused by unexpected events is possible; and (4) in the face of uncertainty, more flexible water management institutions to promote conservation and water transfers, while protecting equities, are advisable. Two institutions spurred the growth of irrigated agriculture by delivering cheap water: the prior appropriation doctrine of water law and the federal reclamation program of the Bureau of Reclamation. As the water available for agriculture declines, the prior appropriation system of water rights can be expected to (1) aid the farmer who desires to profit from the sale of his water rights to other users; (2) compensate the farmer whose land and water is condemned against his wishes; (3) require the farmer to waste less water; (4) allow the farmer with junior rights to be displaced by senior rights, such as Indian water rights; and (5) provide a cause of action for the farmer whose water rights are impaired by one or more late-comer appropriators. Irrigated acreage in the West has doubled since World War II, expanding increasingly away from the southern arid tier to the central and northern high plains states. The reclamation ethic appears to have crested, however, and the federal influence in water policy seems to be waning as the water management role of the states is waxing. Unexpected events, such as an unparalleled oil crisis or expanded famine, could alter current trends.

Whatever the future holds, more flexible water management institutions are advisable for the welfare of all the water use sectors.

― 52 ―

From Reclamation to Reallocation: Historical Overview Agricultural growth in the West was spurred by legal-political institutions that delivered cheap water. Chief among those institutions were the prior appropriation doctrine and the federal reclamation program. Early settlers had little incentive to commit capital and labor to construct water diversion and distribution systems if there were any risk of other users moving in upstream and leaving them high and dry. Therefore, western states developed the doctrine of "first in time, first in right". This law of prior appropriation allowed the first user on a stream to obtain a priority over all other subsequent users, and so on down the line. Prior appropriation facilitated western expansion and agricultural development because water could be parcelled out to a large number of irrigators, and priority dates signalled the extent of risk in situations of drought. Even when existing streams were fully appropriated, agriculture continued to expand by augmenting supplies through the federal program to reclaim the arid and semiarid West. The 1902 National Reclamation Act codified the goal of making the deserts bloom, ushering in the developmental era of heavily subsidized, and increasingly centralized, large-scale irrigation projects.[1] The Act, its amendments, and individual project authorizations provided the legal structure for long-term, interest-free financing based on "ability to pay", and further institutionalized the notion that unappropriated and undeveloped water was itself free, its only cost being the capital cost of constructing works and the subsequent operation and maintenance cost. The government's powers of eminent domain, navigation, and commerce were available for these projects constructed by the Bureau of Reclamation. The Bureau intercepted most major waterways in the West with a series of dams and diversions. Interbasin transfer projects were commonplace. The reclamation program spurred the creation of water districts (mostly public, special districts) as entities responsible for repayment, operation, and maintenance functions. Contract obligations were deferred in projects experiencing hardships. Areas with the most political power in Congress were generally benefitted first. In the post-World War I period, the public works ethos mitigated hard economic times and was further

― 53 ―

institutionalized. Law was viewed as an instrument to harness the unruly forces of nature through public resolve, sweat, and engineering. Public hydroelectric power production was promoted as a major means of subsidizing irrigation water development. Indian tribes were largely neglected by this reclamation process. In 1908, the United States Supreme Court held that water rights had been reserved to Indian tribes for their future use incidental to the creation of reservations.[2] These so-called reserved water rights, unlike state-created appropriation rights, are not dependent upon use, and thus may be claimed at any time and are not lost by nonuse. For the most part, Indian water rights remain unquantified, pending court determination and/or Congressional action. However, tribes are becoming increasingly assertive in claiming large quantities of water. Were such claims to be honored, some present irrigationists would be affected, especially along streams such as the San Juan in New Mexico, which may already be over-committed. With water demand pressing close upon water supply all over the West, and with few good prospects for increasing supply, there seems little alternative to a reallocation of existing supplies among new and established users. Since irrigated agriculture consumes between 80 and 90 percent of total water supplies in most western states, and since the value of water for crop production is ordinarily lower than for alternative uses such as energy, some agriculture is in the position of being bought out. The relative position of agriculture with respect to water supply will now be explored from the perspective of legal and institutional history.

Water Law and Agricultural Water Scarcity Layers of Law[en3]Layers of Law[3] Water law in the West often comes in layers, ranging from the macro to the micro. If an international drainage is involved (like the Colorado, Rio Grande, and Columbia Rivers), a treaty normally governs the division of water between nations. If the water flows between states, an interstate compact (or possible litigation) apportions it. Within a particular state, the water laws (statutes, court rulings, and administrative decisions) define how individual property rights in water are created, exercised,

― 54 ― and protected, except to the extent that superior federal or Indian rights are involved (e.g., navigation servitude, "reserved" water rights, and federal eminent domain). Generally speaking, the international, national, and

interstate laws make the broad allocations which determine "state entitlements"—the amounts of water which, when added to the water local to a state, are available for use within that particular state. Agriculture can be affected by laws at all these levels, as a few references to the Colorado River Basin will illustrate. The U.S.-Mexican Water Treaty of 1944 contained no express provision for water quality. Highly saline irrigation drainage from the United States' side precipitated conflict in 1961, leading to U.S.-Mexican agreements and a United States salinity control program which together affect irrigation water management in the states of the Colorado River Basin. Two interstate compacts—the Colorado River Compact of 1922, and the Upper Colorado River Basin Compact of 1948— together control allocations between the upper and lower parts of the basin and between the seven states of the basin, subject to unresolved claims relating to federal and Indian "reserved" water rights. Because the flow of the river was overestimated in 1922, the upper basin's legal obligation to deliver water to the lower basin means that the upper basin has 1 to 2.25 MAF less each year than originally planned. That kind of shortfall raises the level of competition between agriculture and other uses. The 1922 Colorado River Compact contains a pro-agricultural bias, declaring domestic and agricultural use to be superior to the generation of electricity. Both the 1922 and 1948 compacts preserve Indian water right claims which, when quantified, could displace or devalue the agricultural water rights of non-Indians. Federal authorization of the Central Arizona Project (CAP) conditions agricultural water delivery on reducing pumping, practicing conservation, and not irrigating new acreage. When the CAP comes on line several years from now, some California irrigation (which has been based on flow destined ultimately for Arizona) could be cut back. With most of the federal reclamation projects in the western U.S. completed or authorized, state water laws provide the layer of legal rules that now most influence water availability for irrigation. Each state has its own water law system, although similarities exist across state lines. The state water law systems decide who gets how much for what uses. While mining predated irrigation in some of the western states, on the whole

― 55 ― irrigated agriculture has dominated the acquisition of water under the water right systems of the West since the early days of those systems. The water laws of the western states variously were initially designed or later shaped to promote, not limit, irrigation development.

State Law of Surface Waters: Prior Appropriation[en4]State Law of Surface Waters: Prior Appropriation[4] Under the "riparian doctrine" which has prevailed from the outset in the humid eastern states, the right to use water from natural water courses is held by the owners of land adjacent to the water. The western states for the most part rejected the riparian approach, adopting the "prior appropriation doctrine" which allowed water to be diverted away from riparian land. (See map of surface water rights systems, Figure 2.1.) The appropriation doctrine rests on two fundamental principles: (1) priority in time, and (2) beneficial use. The priority principle—first in time, first in right—allocates available water in times of shortage to those who first began their use of water from the source. Persons with the earliest priority may have their rights completely satisfied, while persons with the latest rights may receive no water at all. This "first in time" rule is offset by three large exceptions. First, in most states, certain preferred users receive their full appropriation regardless of their priority. Preference is normally given to domestic and municipal uses and often to uses for agricultural purposes. Some states also provide a judicial mechanism through which preferred users may condemn the water rights of less preferred users. Second, appropriators may agree among themselves that during times of shortage the burden of the reduction in supply will be shared by a system of rotation or some other way. Third, sharing of shortage is often found in large projects where a number of irrigators share in the project's priority. The term "beneficial use" is not subject to precise definition, but it generally includes two related, but somewhat different, concepts: social utility and engineering efficiency. That is, a use is beneficial if it involves some socially accepted purpose and if it makes a reasonably efficient use of water. In the past most consumptive uses, particularly irrigation, have been considered beneficial. The types of uses socially accepted as beneficial uses have been increasing. Gradually, "instream" uses, such as the preservation of minimum flows to preserve fish, wildlife, and recreation values, which do not involve the "appropriation" of water, are becoming recognized as

― 56 ―

Figure 2.1 Surface Water Rights Systems Source: Gary Weatherford (ed.) et al, Acquiring Water for Energy (Littleton, Colorado: Water Resources Publications, 1/82), p.32. John Muir Institute

― 57 ― beneficial uses. New energy-related uses, such as dewatering mines and slurrying coals, are being regarded as beneficial by most affected states, increasing the basis for competition and the justification for public regulation involving the exercise of broad administrative discretion in assessing tradeoffs and balancing interests. Thus, beneficial use is a dynamic, not static, principle.

A person who wishes to divert water for a beneficial use must apply for a permit to a designated state agency. The typical scheme is generalized in Figure 2.2. Public notice is given and a hearing is offered to other right holders—sometimes to affected members of the public also—who object to the proposed diversion. The date of application usually determines the priority of the use. The state will generally issue the permit if it determines that the proposed use will not interfere with existing uses ("nonimpairment"), that unappropriated water is available, and that the project is not otherwise contrary to the public interest. Upon completion of the diversion and application of the water to a beneficial use, an appropriator must file proof of appropriation which, upon verification, is followed by the issuance of a certificate of a perfected right. This right extends only to the amount of water actually diverted and applied to a beneficial use, even if a larger quantity was originally intended. Under most irrigation uses of surface water, a significant portion of water applied returns to the watercourse as "return flow." A purchaser of appropriation rights who merely continues the same use as his predecessor need only comply with local recording laws to perfect the right. An application for a new permit must be filed, however, if either a purchaser or the same owner intend to change the nature of the use, which may mean a change in the point of diversion or in the purpose or place of use. State approval helps to guarantee that the proposed change will not interfere to a greater extent than did the prior use with the existing rights of others, and that the new use is in the public interest. The application process for proposed changes is similar to that followed for the initiation of new rights. Approval depends on a determination that other rights will not be impaired and that unappropriated water is available (in the event that the change of use is more consumptive than the prior use). Some states will not permit a transfer in the place of use if it involves the transport of water outside the watershed of origin or outside the state. And some states will not authorize a change in the type of

― 58 ―

Figure 2.2 Permit Procedure: Prior Appropriation States Source: Gary Weatherford (ed.) et al, Acquiring Water for Energy (Littleton, Colorado: Water Resources Publications, 1982), p.50. John Muir Institute

― 59 ― use where the prior use is preferred over that use which is to replace it. With the prior appropriation doctrine thus described, the question arises: What relationship might exist between this prior appropriation system and diminished water for agriculture? The simple answer is that the system in

most instances will (1) aid the farmer who desires to retire by selling his land and water profitably to nonfarmers; (2) compensate the farmer whose land and water is condemned against his wishes; (3) possibly reduce, under changing notions of conservation and "reasonableness," the amount of water the farmer has been diverting or consuming; (4) subordinate the farmer with junior rights to newly asserted senior rights, such as Indian water rights; and (5) provide a cause of action for the farmer whose water rights are impaired by one or more late-comer appropriators. These results will occur in the following ways. Appropriative rights are quantified and, in most areas, marketable.[5] (See Chapter 18.) Individual farmers and farming interests themselves will reduce the water available for agriculture by selling out at attractive prices to nonagricultural users, such as cities and energy companies. Appropriative rights are property rights; if they are condemned by a public agency or authorized utility, compensation must be paid. For the farmer who continues to exercise his appropriative right, he may find that changing legislative, judicial, or administrative notions of "reasonable use" and "public interest" require that he be more efficient in his water use, that is, use less water on the same acreage. In some cases, he may be allowed to use the water saved on expanded acreage, in which case no overall reduction in agricultural water occurs. If the farmer's priority date is later than that of an unexercised Indian water right, the initiation of the Indian water use can reduce or eliminate the farmer's supply. To the extent that he is the senior appropriator in time, however, competing junior uses cannot lawfully impair his right, although problems of proof and costs of enforcement place practical limits on this protection. Because irrigated agriculture enjoys 80 to 90 percent of the water consumption market in the West pursuant to these vested property rights, it is in a position generally superior to other water competitors. Agriculture acquired permanent rights in the water, with the aid of public subsidy, in the formative days of settlement and water rights administration. Within limits, those rights are subject selectively to superior claims and to

― 60 ― redefinition in the public interest. For the most part, however, irrigated agriculture will bargain from a position of strength in the competitive arenas of water scarcity, even though not all individuals or interests in the agricultural community are benefitted or protected in the process.[6]

State Groundwater Laws[en7]State Groundwater Laws[7] Present indicators are that much of the decline in agricultural water supply in the West will result from dwindling groundwater resources in such overdraft

areas as the multistate Ogallala Aquifer, central Arizona, and the San Joaquin Valley of California. Overdraft conditions have been permitted or countenanced by the groundwater legal systems of the affected states. Most groundwater basins are hydrologically connected to surface flows and ought not, from a management perspective, to be regarded apart from surface flows. There are four principal legal systems governing groundwater acquisition in the western states: absolute ownership, reasonable use, correlative rights, and prior appropriation. We do not offer here exposition of the various state groundwater systems. (See Figure 2.3 for a map showing the diversity of approaches in the West.) Some states have drawn geographic lines between those areas which are critical and those which are not. The definition of a "critical area" or "capacity use area" is generally an area in which the annual rate of withdrawal exceeds the average annual recharge (the common definition of groundwater mining) or threatens to do so. The distinction between critical and noncritical areas may determine whether a proposed well is subject to regulation at all, or the degree of scrutiny the permit application will receive. In some cases, critical areas are subject to governance by local groundwater management districts. Also, critical areas may be controlled by express statutory prohibitions. Sometimes special protection or preference is given to groundwater service areas which are more expansive than just the land overlying the aquifer itself. Many of the observations made earlier about the role the prior appropriation doctrine plays under declining water conditions apply to groundwater systems as well. Groundwater rights likewise are property rights; generally they are transferable and enforceable against impairment. To the extent that groundwater becomes more regulated, with more controls on the depletion of critical aquifers, it is probable that less water will be available to

― 61 ―

Figure 2.3 Groundwater Legal Systems Source: Gary Weatherford (ed.) et al, Acquiring Water for Energy (Littleton, Colorado: Water Resources Publications, 1982), p.100. John Muir Institute

― 62 ― overlying agriculture. It is likely, however, that the decline in groundwater for agriculture will be more attributable to rising pumping costs than to legal regulation.[8]

Political Institutions and Changing Patterns of Influence The reclamation era of large-scale water resource development was dominated by the federal government. The sources of federal influence were the geographic scope of its jurisdiction, its financial resources, and its technical expertise residing in federal agencies. The development of numerous water projects up and down whole river basins spilled across state lines. Control naturally gravitated towards the federal level because the geographical reach of state boundaries was too limited. Moreover, water resource development projects were expensive, and required access to the federal treasury which is much less restricted than the coffers of the states. In addition, the manpower and technical expertise requirements of major water projects led to federal responsibility for large-scale construction. The Bureau of Reclamation, the Army Corps of Engineers, and the Soil Conservation Service had a continuing critical mass of engineers and water planners that no state could hope to maintain. In what observers have termed classic distributive politics, federal agencies orchestrated blends of local and state interests in providing basic support for individual projects.[9] Different project features lured different interests. Farmers were attracted by irrigation water, urban interests were promised water supplies and flood control, recreation groups appreciated lakes created by impoundments, and businessmen and bankers desired water projectgenerated economic growth. Agriculture was important in this coalition of interests because its demands could justify the development of large quantities of water. The rewards for agriculture's backing were long-term contracts for federal water at very reasonable rates, and agencies were generous to farmers in matters of eligibility. For instance, the 160-acre limitation was loosely applied by the Bureau of Reclamation. The role of the states in water development policy was to deliver a unified state congressional delegation in support of projects within state boundaries and the favorable testimony of governors and state agency officials. Mainly the federal piper called the tune in the 1950s and 1960s.

― 63 ― The 1970s witnessed the decline of federal construction agencies and the challenge to federal dominance of water policy. Because of the facts and forces already described, traditional water development patterns were severely disrupted. The number of new starts in water development projects declined, and the share of water agencies in the federal budget grew smaller. The Soil Conservation Service, the constituency of which was mainly agricultural, was brought to task for channelizations that destroyed fish and wildlife habitat. The Bureau of Reclamation, which once was the largest agency in the Department of the Interior, and in 1950 commanded 61 percent of the Department's budget, fell upon even more difficult times.[10] Plans for large-scale construction, such as the two dams proposed for the Grand Canyon, were repeatedly defeated on economic and environmental

grounds. In a symbolic act, meant to signal the end of the Bureau's mission of large-scale construction, the Carter Administration stripped the Agency of its name, and for a period of three years it was called the Water and Power Resources Service. The failure of the Carter Administration to achieve its aims in water resources has been popularly recognized as a defeat for environmentalists, while the decline of the federal government's influence in water has received less notice. An important dimension of the water conflict lurked behind the headlines of the time—a struggle between the states and the federal government over their respective influence and roles in water allocation. Carter's "hit list," which zero-budgeted thirty-two projects, was a direct challenge to the states' growing determination to set their own priorities regarding water resources. The negative reaction from Congress and state houses was marked. The second line of attack for water reform was a federal agency review of water policy which involved little state and local participation. The Carter Administration's issue and options documents which resulted from the agency review were coldly received by the states, especially the option of federal intrusion into water rights granted by individual states. In the end, most of the projects on the original hit list went forward, and a considerably watered down version of the new national water policy was adopted and then was implemented only partially.[11] The new Secretary of Interior in the Reagan Administration dismantled the water policy machinery, including the Water Resources Council, and made it clear that he recognized water resources as primarily a matter of state rather than federal concern.

― 64 ― The lesson from these events is clear. Since the federal government can no longer afford to award large numbers of federally funded and constructed water development projects as prizes, its influence over water management is considerably weakened.

Increasing State Influence The events of the Carter years pointing toward an increase of state influence vis-a-vis the federal government have been reinforced by other forces. One such influence has come from the courts, which in the late 1970s landed some judicial blows on the notion of federal dominance. First the Court said that federal reserved water rights were more restricted than previously imagined. The attempt by the U.S. Department of Justice to expand the reserved water rights of national forests to protect instream water for fish and wildlife was rejected by the Supreme Court on the grounds that such federal claims infringed on the historic role of states in water allocation.[12]

Further, in a California case, the Supreme Court held that the federal government must follow the rules and regulations of the State in the operation of a project even though the project was federal.[13] Considerable constitutional power to affect water management is still lodged in the federal government, however, as the U.S. Supreme Court reminded us on the last day of its term in 1982 in Sporhase v. Nebraska (No. 81-613; July 2, 1982). This case held that the interstate movement of groundwater, as an article of commerce, cannot be restricted by states engaged in economic protectionism. The decision buttresses the free market and federal regulation (those estranged bedfellows of old), and undercuts states' rights. It is not likely, however, that the equitable and distributional values asserted by states will evaporate simply because there has been a judicial pronouncement. It would not be surprising to find the western states seeking federal legislation (congressional exercise of the commerce power) legitimating to the degree possible the states' efforts to control and manage water resources. The capability of states to manage water resources has grown in the last couple of decades. The focus and reliance upon federal agencies during the reclamation era worked to stunt and distort the growth of state water planning agencies and policy-making structures. Up until the mid-1960s, the number of professional planners was quite small and there was little attempt at state water planning independent of federal plans. The picture is enormously changed in the 1980s. While legislative authorization for

― 65 ― addressing water resource planning is far from sufficient evidence of state capability, the presence of such mandates facilitates forceful state action. As Figure 2.4 illustrates, the types of legislative mandates given to states vary enormously, yet the map shows that most states provide for comprehensive water quantity planning, and in many cases this is combined with management, and/or water quality planning and/or management. While undoubtedly these structures were developed partly in response to the availability of federal grants-in-aid, agencies now represent a considerable pool of expertise and influence that is likely to survive, at least in part, even if federal monies are withdrawn.[14] The independent actions of individual states in relation to water resources both contribute to and are evidence of growing state influence. These actions are sometimes not consistent, indicating considerable differences in the priorities of different states. For instance, in 1977 the Montana legislature declared "the use of water for slurry to export coal from Montana is not a beneficial use."[15] On the other hand, South Dakota determined to sell a share of the state's Missouri River water out of Oahe reservoir to an interstate coal-slurry pipeline company on terms that provided low-cost

water to several towns along the pipeline route.[16] Numbers of other states similarly are acting on the allocation, use, and preservation of state water resources. In 1982 the Governor of Wyoming proposed to the legislature that the state appropriate $100 million per year for six years to develop the state's water resources.[17] In 1980 Arizona adopted a comprehensive new groundwater code aimed at bringing the state's depleted aquifers into a "safe-yield" situation by the year 2020.[18]

Implications for Agriculture Land irrigated for agriculture in the West has roughly doubled since World War II, and the addition of 25 million acres in the West has contributed heavily to American agriculture's 70 percent increase in crop production during the post-war years.[19] A healthy chunk of this expansion has come from high production farming on arid lands, perhaps as much as 13 million acres, that are unsuitable for commercial agriculture without irrigation. The focus of growth in the initial phase, 1945-1954, was in the arid southern tier of states extending from Texas and Oklahoma

― 66 ―

Figure 2.4 State Statutory Authority for Water Resources Planning and Management Source: Kenneth Rubin, "The Capacity of States to Manage Water Resources Given a Decreased

Federal Role," prepared for Symposium on Unified River Basin Management, Stage II, Oct. 1981.

― 67 ― to California. Subsequently, increases in irrigated acreage have come from central and northern high plains states.[20] Among the most important factors underlying this growth has been an abundance of relatively inexpensive water. While the accomplishments of the National Reclamation Act of 1902 that made the Great American Desert bloom have been striking, there are many signs, noted above, that the reclamation ethic has crested. The decline of federal influence in water allocation has a mixed bag of consequences for irrigated agriculture. Clearly the closing of the option of developing large-scale additional supplies at the same time as demands are growing generates pressures upon the largest of the users of existing supplies. At the same time it is possible to question the extent to which agriculture ever controlled the flow of benefits from federal water projects. In the interests of gaining broad support, federal agencies regularly served numbers of other interests including urban users, energy, industry, and fish and wildlife at the expense of agriculture. A retrospective study of the Central Arizona Project indicates that in the thirty-three year history of negotiations, farmers were forced to make a number of compromises to save the project. The current project design will afford farmers far fewer benefits and more costs than if they could have continued to pump groundwater.[21] The change of emphasis at the federal level in the management of existing projects has important implications for agriculture. While the Carter and Reagan Administrations have differed enormously in their approaches to water resources, both have emphasized the principle that users should pay more nearly full costs. Irrigation interests are likely to be charged considerably more for water when long-term contracts for water at existing federal installations fall due. Whether or not the federal government will use the leverage it has for other purposes remains to be seen. With the support of the Reagan Administration, Congress has modified the 160 acre limitation to the point where it poses little or no problem to most agriculturalists. In the case of the Central Arizona Project the federal government appears to be making good on its trust obligations by influencing allocations to benefit Indian tribes. The future of federal support of Indian water rights is not at all clear, however. The Reagan Administration has favored negotiation rather than litigation in securing Indian water rights. The reserved water rights position of many tribes is legally very strong, and even without active federal government backing may fare well in the courts. Indian

― 68 ― victories in water allocation mean all junior users, including irrigated agriculture, stand to lose. The shift of influence in water allocation towards the states raises the issue of the relative influence of agriculture in federal and state arenas. On the face of it, the structure of Congress would appear more favorable to agriculture than state legislatures. Rural farming states have the same number of votes in the Senate as do more urban and more populous states, while both bodies at the state level are apportioned on the principle of one man-one vote. Further, the influx of people into urban areas in many agricultural states, and the depopulation of the hinterlands, especially in the West, has resulted largely in urban populations. In Arizona, for instance, seventy-five percent of the population lives either in Phoenix or Tucson. Yet the preferences of legislative bodies are often different from what one might expect. In practice, the U.S. Senate has been more oriented toward urban interests than the House, because practically every Senator has at least one large urban area in his or her state. Further, the court ruling requiring apportionment of state legislatures on the basis of population has had less impact on the traditional rural bias of state legislatures than one might suppose. In many state legislatures agriculture has had influence far in excess of what the number of rural districts would suggest because urban areas lack cohesion and rural legislators often have skill, seniority, and command of formal positions. The attitudes of state voters is likely to be important in determining how state governments will treat agriculture. While public opinion surveys on questions of water allocation are infrequent, those that have been reported should be reassuring to agricultural interests. A survey of voters in the four corners states of Arizona, New Mexico, Utah, and Colorado found more than 90 percent of respondents in favor of allocating more or the same amount of water to irrigated agriculture in the future. This support was strong even among urban residents.[22] Customers in the Salt River Project area were asked in another survey if as a conservation measure they favored or opposed raising the cost of water to farmers growing food and fiber. Eighty-three percent of respondents opposed such action, compared with 64 percent opposition to similar price increases for residential users and 54 percent opposition for business and industrial users.[23] While such data cannot be construed as a reliable indicator of what urban users would do if they really had to choose between their own interests and those of agriculture in

― 69 ― water matters, those surveyed do testify to the reservoir of positive attitudes

toward agriculture. The policies pursued by some states in water allocation evidence similar basic concern for the welfare of agriculture. Henry Caulfield has written of the predilection of Colorado water leaders toward the development by the state and private entities of unappropriated water and surplus water from wet years to serve the energy industry and growing populations. This is viewed as much preferable to cutting back agriculture's share.[24] The Arizona groundwater reform act does envision the reduction of agricultural consumption of water to a level of "conservation use" to be set by the State Department of Water Resources. At the same time, "grandfathered water rights" favor all existing water users at the expense of future users who are likely to be residential and industrial.[25] To summarize, the rise of states in the changing pattern of political influences is affecting irrigated agriculture, but there is much to suggest that the position of agriculture remains strong. State houses are likely to be as sympathetic to agriculturalists as were federal agencies that dominated water politics in the reclamation era. Particular pressures will be brought to bear upon agriculture because it historically has used large amounts of water and paid little, and demands of new water users must somehow be satisfied. At the same time it is reasonable to expect that state governments will do what they can to cushion the impact of water reallocation upon agriculture in the name of perpetuating the agricultural economy and preserving the rural lifestyle.

Unexpected Events and Unanticipated Consequences The discussion up to this point has assumed an incremental future. In a world where dominant events are often unforeseen, however, it is risky not to consider the unexpected. It is possible to imagine in passing a number of events that would thrust water once more into the national arena commanding federal attention. It is also possible to imagine that the devolution of power over water allocation from the federal government to the states might be more rapid than we anticipate. Because water is so crucial an element in energy, agriculture, and economic productivity, it may be that a crisis in any of those

― 70 ― sectors would quickly put water on the national agenda. If our oil supplies were threatened again, more seriously than the Iranian oil embargo, as by a revolution in Saudi Arabia, unparalleled pressures would be brought to make the U.S. energy-independent. The federal government undoubtedly would have to take the lead in directing such domestic energy development. The

record of private enterprise on synfuels in the past, even with healthy subsidies, does not warrant the expectation that the response of the private sector alone would be adequate. The energy industry by now is clearly skeptical of risking capital in synfuels development, as Exxon did in the oil shale boom. The federal government might well react to an energy crisis by causing large amounts of water to be shifted from agriculture to energy. It might be that states could bargain to protect agriculture, and the time necessary to get energy projects under way could be long enough that agriculture could outlast the crisis. Nonetheless, rapid federal energy development in a crisis situation bodes ill for farmers' retention of water. On the other hand, an enlarged famine caused by crop failures abroad, in conjunction with the growing importance of agriculture in U.S. balance of payments, could help U.S. farmers. Expanding food crises could boost federal assistance to farms and raise farm prices. The already favorable public attitude toward irrigated agriculture in the West could be amplified. New federal projects that benefit agriculture might be authorized and funded. The authorization and funding of a large number of new projects, for agriculture as well as other purposes, could be spurred by an economic crisis prompting a New Deal type of public works response employing lots of people. Other changes could be ushered in by a rapid rise in the interstate movement of water.[26] As water comes to be treated more like any other commodity, and becomes more overtly commercialized, many private water rights could become transferable to the highest bidder across state lines, and interstate water compacts could be undercut. It is even possible that agribusinesses engaged in high-value production might be buyers in an interstate water market, although farmers as a whole more often would be sellers. Could equity considerations be protected in such a "free market" environment? Possibly, through either: (1) an Act of Congress and/or (2) state ownership (purchase/condemnation) of water rights to prevent uncontrolled operation of the private market. Would this not pose an identity crisis of significant proportions in the irrigated West? In order

― 71 ― to protect lower-value uses and the natural resource base of each state, a movement could arise to either "federalize" or "socialize" more of the water —alternatives foreign to the current political imagery of western states (although western settlement was partially subsidized by free land and water in the past). Agriculture's historical water rights granted by state governments could be profoundly altered by the emergence of an interstate water market. Two scenarios in which states become more powerful more quickly than we envision here have been offered in a paper by Henry Caulfield.[27] In the

first, power and money is transferred from the federal government via "new" federalism. In the second, states seize the initiative on their own. The second scenario assumes states can determine their own values concerning water, and that they have or can develop the financial and technical capability. Under such conditions we would expect agriculture to fare reasonably well, as we have predicted, although we would not expect states to be equally favorable to farmers.

Conclusions The support for continued agricultural use of large amounts of cheap water is high among state residents, even those in urban areas. Further, irrigated agriculture bargains in state arenas from a position of strength. State water law grants vested property rights to users with long-term, established records. Agriculture acquired permanent rights in water in the formative days of settlement, and those rights are subject to only limited redefinition in the public interest. It is in the long-term interests of agriculture as well as other sectors to develop more flexible water institutions that facilitate conservation and water transfers. The lesson to be learned from the decline in supply solutions for water shortage is that water must be managed for reallocation to highervalue uses and waste needs to be reduced. Barring unexpected events, this will mean some reduction in irrigated agriculture in the arid regions. To a large extent this shift will probably be accomplished through the sale of water rights in the market. Transactions that move water out of irrigated agriculture will cause some negative externalities, such as social and environmental disruption. There may be ways to soften such impacts, however. Rural people may band together through water districts, corporations, or other

― 72 ― arrangements to direct the flow of water to purposes consistent with rural values and the need for rural employment. State governments may decide to enter markets themselves, buying water rights for equity, aesthetic, or fish and wildlife purposes. The use of water that remains to agriculture, that is not sold or leased, will become more regulated. The Arizona Groundwater Act of 1980 devised a flexible groundwater right that is to diminish in quantity over time as conservation technology develops and conservation requirements under the law tighten. The concept of beneficial use, as we have indicated, can be used flexibly, and it is likely that in some states water uses tolerated in the past will be disallowed in the future as not in the public interest.

The lesson to be learned from the marginal decline in the influence of agriculture vis-a-vis other water users is that accommodation rather than outright opposition to modifications in water institutions is advisable for agriculture. Because irrigated agriculture is the largest water user, it is the obvious focus of policies aimed at stretching supplies. While agriculture's legal and political position remains strong, it nonetheless represents only a small percentage of the population in most states. In the final analysis, irrigated agriculture is likely to fare better if it is not perceived to be in direct conflict with other users.

Discussion: Jon Kyl There can be little disagreement with the fourfold thesis of this paper. (1) Even as one of the largest reclamation projects ever developed, the Central Arizona Project, nears completion, western water development inexorably is being replaced by water reallocation and management. (2) The relative position of agriculture is declining, though in different degrees among the western states. (3) In an overall sense, this change is gradual; but in specific areas it is and will be traumatic. (4) Depending upon how one defines the term, flexible water management to promote conservation and water transfer is, indeed, advisable. Whether it must be effected through "institutions," as opposed to incentives, legal requirements, or the free market, will be subject to debate. Laws and public policy respond to the times. As more people compete for scarce resources, one of two things happens. If the free market is allowed to operate, the price of the commodity goes up, resulting in some measure of conservation. Alternatively, if the price goes too high, or if the owners of the resource are too politically weak, or if, for other reasons, policy makers deem it necessary or expedient to regulate the resource by exercise of police power, a nonmarket political redistribution of the resource may result. Such a result is inevitable if the regulation is stringent and pervasive enough to amount to a "taking" of the resource. Reallocation of the scarce water resources in the West is occurring through both operation of the market and newly-imposed regulation and management schemes. What may most influence the allocation of our scarce water resource is the Indian water claim. This emerging problem calls for more discussion, because it could dwarf the difficulties heretofore encountered by competing non-Indian claims. In Arizona, for example, application of the "practicable irrigable" acreage test of Arizona v. California, 373 U.S. 546, 600 (1963), would result in allocation of the entire dependable water supply of the State to just one-third of the Indian tribes, leaving two-thirds of the tribes and all non-Indian Arizonans with nothing.[1] No solution to this problem is yet evident. Congress has been unwilling to initiate any process for quantification of Indian claims, and the Tribes have been unwilling to cooperate in such quantification through the courts—especially in state-court McCarren Act proceedings. With the stakes as high as they are, it is quite possible that changes brought about by resolution of

― 75 ― Indian water claims will not be incremental and could be traumatic. Even if it is assumed that Indian tribes which cannot use the large amounts of water claimed can and will sell part of their entitlement to non-Indians, recent expansion of Tribal "sovereignty" by the Supreme Court[2] casts doubt on the extent to which non-Indians will do business with the Tribes. Since there is no practical way of resolving legal disputes with Indians (because of Tribal immunity in state and federal courts), it is doubtful that many entrepreneurs will place their operations and fortunes at risk on agreements to use Indian water. Indian reserved water claims are, in short, much more significant than suggested in this paper. In the section on state groundwater laws, several statements deserve comment. First, it is not necessarily true that most groundwater basins are hydrologically connected to surface flows. In Arizona, for example, most groundwater aquifers have no hydrological connection to surface flows. It is likewise incorrect to assume that, from a management perspective, surface flows ought to be treated with "flows" of groundwater. Second, at least according to a recent pronouncement of the Arizona Supreme Court, it is not necessarily true, as the authors state, that "groundwater rights likewise are property rights . . . transferable and enforceable against impairment." Both the State Supreme Court and the Federal District Court in Arizona have now held that there is no constitutionally-protected property right in groundwater in one's land—that the doctrine of reasonable and beneficial use gives the landowner only a right to use, which can be regulated and taken by the state.[3] This recent interpretation and the Supreme Court's validation of the comprehensive 1980 Groundwater Management Act also cast doubt on the authors' prediction that, in Arizona at least, ". . . the decline in groundwater for agriculture will be more attributable to rising pumping costs than to legal regulation." These corrections are not meant to take issue with the validity of the paper's observations, only to point out that recent legislative and court actions in Arizona have changed the facts. Even though the doctrine of reasonable and beneficial use gives a landowner only the right to use, the authors are correct that that right has been characterized as a constitutionally protected property right.[4] As to the statement that reductions would occur through increased pumping costs, the minority report to the State Commission which developed the Arizona law agreed with

― 76 ― the authors—that the natural market forces of price and increased pumping costs (due to lower water depths and higher gas and electric charges) had in fact reduced and would continue to reduce agricultural pumping without the necessity of a regulatory law designed to accomplish the same objective. Two additions to the short discussion of the Arizona Groundwater Act are suggested. First, though "grandfathered rights" favor existing water users, the transformation of a prior common law right into a new state-regulated statutory right has diminished the value of the "right" considerably. Second, after 2006, the Act authorizes the State to purchase and retire agricultural lands if, in addition to other conservation measures, that action is necessary to achieve a balance between water consumption and supply in management areas. Finally,[5] it is difficult to argue with the last paragraph of the paper. However, that conclusion also reveals the difficulty of the challenge to agriculture. When "vested property rights" were, in the view of many in agriculture, eliminated by competitors in the State of Arizona,[6] it is a significant challenge indeed for agriculture to portray its uses of water as not being in conflict with other users. In conclusion, the paper substantially contributes to an understanding of the water problems facing agriculture. Its value would be enhanced by more discussion of two points. First, the changes already brought about and those predicted may pale in comparison to the accommodations which would be necessitated by full-scale application of the "practicable irrigable" test for federal reserved water claims on Indian reservations. Second, competition for water among non-Indians has already resulted in at least one state redefining the legal status of a right to use groundwater, with the result that agriculture's "vested property right" became a noncompensable stateregulated ability to use. Depending on how Indian claims are resolved, and on political conditions in other states, future changes in western agricultural water rights and uses could be dramatic.

Discussion: Frank J. Trelease Ordinarily the job of a discussant is an easy one, but this assignment has suddenly turned into a difficult task. Usually the discussant's plan of action is to challenge the premises of the paper, meet them head on, and engage in close combat. In this instance the search for the fatal flaw failed. The first reading disclosed only tiny chinks in the opponent's armor, and hope failed as the conclusion finally revealed the awful truth: I agree with practically everything said by the authors.

― 78 ― The authors end with predictions and forecasts, and even the unexpected and unanticipated is explored. Any prediction can be attacked as unrealistic. Yet my crystal ball seems no more free from cloudy spots, cracks, and distortions than theirs, and since I have lived long enough to see many of my own doom-sayings exposed as wrong, naive, and even foolish, I hesitate to claim any superiority as a seer. The most I will attempt is to throw a few more straws into the wind and see which direction they point—always remembering that a straw has two ends. Some seem to fall crosswise. The paper identifies reserved Indian water rights as threats to present agriculture, but the sad fact is that while Indians have the best water rights in the West, they have the least water. On most reservations, substantial projects would be needed to translate the dry paper water rights into wet water in the ditches, and in my opinion there is small chance of obtaining federal funding for works that would take water from present users. The best hopes seem to be for joint water from present users. The best hopes seem to be for joint on-and-off reservation benefits similar to the on-going Central Utah Project, the proposed Yamkima scheme, and the still viable Papago settlement. It is also possible that the era of federal agricultural subsidy may not be entirely over. Ogalalla aquifer underlying parts of seven high plains states has been overdrawn in Texas since the 1940s. Only two states on the fringes of the aquifer have recognized that irrigation use of this water is a mining process, and that when the water is exhausted (or fallen too deep) the overlying farmland must revert from irrigated crops back to dryland wheat or cattle grazing. Colorado and New Mexico have at least restricted pumping to ensure that farms could be amortized and that too-quick exhaustion would not bring bankruptcy before payout. Yet now that the "water mines" are nearing exhaustion, cries of help are heard, and the United States is investigating the possibilities of a massive rescue attempt by bringing water from the Missouri River and possibly the Sabine River. Initial guesses as to costs are tremendous, but so also can be the presures from seven Congressional delegations. The authors see possibilities of another energy crisis that might lead to quick conversion of water from farms to fuel. A third crisis, however, may convince us that we have a long-term energy problem that requires a long-term solution. In that case, urban and rural support for the notion that new energy demands must be satisfied by finding new supplies of water can probably be counted on to continue. "Let them find their own water, not

― 79 ―

take ours" could lead to more federal dams to store and make available the small amounts of unappropriated water left in many areas. Even in Montana, where unappropriated water still flows in the Missouri River and its principal tributary, the Yellowstone, the state's water reservation process sets aside all free flows and on-stream dam sites for future agriculture, leaving only expensive off-stream storage for energy. Future federal rescue and energy projects would be enormously expensive subsidies to agriculture. Recognition of this has led to some tension in the states between throwing roadblocks in the path of energy and improving procedures for orderly market transactions. If states are to react responsibly to the need for an efficient economic transition from agricultural use to energy, they must enact better laws. The present systems designed to protect agriculture and prevent transfers still allow cash to talk and spotty unplanned transfers to appear. Current procedures protect priorities of other water users, but not farming neighborhoods and lifestyles. Wyoming made a start with a requirement for something like an economic impact statement to support a petition to approve a transfer, and still better devices could be employed. The states should find ways to internalize the effects of large transfers of farm water on local communities, districts, and economics. There is a need to institutionalize the water right, to make it more easily transferable. The states should find ways to encourage marginal water to move to industrial and municipal use; currently these users seek the earliest and best water rights. Another need is to find ways to encourage conservation to cut back present agricultural demand. Most discussion of water management is either on a high moral plane or calls for tough regulation and imposition of expensive practices. There should be better incentives; the water user should reap where he has sowed, and he should not be asked or forced to spend his time and money for his neighbor's benefit. The authors pose a possible interstate market in water rights, inspired by the recent Sporhase case that struck down Nebraska's curbs on the export of water from the state. Yet Sporhase itself called attention to another recent case, New England Power Company v. New Hampshire, which opens the door to Congressional reversal of Supreme Court decisions that prevent state interference with interstate commerce. Currently the Senate is struggling with a coal slurry pipeline bill (S.1844) that would do just that: permit states to impose conditions on energy companies exporting water as a transportation medium. Yet this brings in

― 80 ― another countervailing consideration. Midwestern Congressmen see the slurry pipeline (which would take water from the Missouri River) as the tip of an iceberg that threatens to sink navigation. An Iowa Congressman has

introduced a bill (H.R.5278) that would prohibit a state from diverting water from an interstate basin unless all states in the basin agree—a move applauded by some from the Great Lakes states who fear an only slightly more remote threat. Since such legislation would undoubtedly mean the death of any more upstream interbasin diversions, the western states would be solid against it. A fair prediction on the outcome is that things will remain the same. As the authors try to foresee the unforeseeable, they instance two scenarios by Henry Caulfield for state development of water. One is the "New Federalism" approach that would divide federal water development money among the states. The other is state capability to do a large part of it alone. As for the latter, California (with its rejection of the "Peripheral Canal") may have run out of patience with rescue projects, Arizona may have run out of water, Nevada out of land, and most of the others out of money. Perhaps the federal block grant is a possibility. If the states do go for a supply-side solution that creates a bigger pie for all, rather than cutting a slice for energy out of agriculture's share, will the problem and the conflict merely be escalated to a new level? If agricultural interests are as strong in the states as the authors suggest, it should be interesting to watch how big a slice of the new "energy water" they will try to take for themselves.

― 81 ―

Chapter 3— Competition for Water by Kenneth D. Frederick and Allen V. Kneese

Abstract The growing scarcity of water in the West already has curbed the expansion of irrigated agriculture and promises to impose further constraints in the coming decades. Nevertheless, declines in irrigated acreage will be limited to the most water-scarce areas and will tend to be modest in scale. Since irrigation now accounts for about nine out of every ten gallons of water consumed in the West, large percentage increases in consumption for other uses can be accommodated with small relative reductions in agricultural uses. Opportunities for conserving water and increasing output per unit of water will further limit the negative impacts on irrigated agriculture. There are areas where water supplies are sufficient to support an expansion of irrigation. For the West as a whole, the Second National Water Assessment projects increases of 10 percent in irrigated acreage and 6 percent in water consumed for irrigation from 1975-2000.

Some of the adjustments which have only marginal impacts on overall western water use and development may have major impacts within specific locations. The point is illustrated by examining the potential impacts of energy development on the character and beauty of the Yampa River. Full appropriation of water supplies presents a major challenge to the institutions allocating western water. If these institutions permit flexibility of use in response to changing demand and supply conditions, water will not be a barrier to either agricultural or nonagricultural development in the West.

The West is undergoing a major transformation with respect to water. In the past, increasing water demands stemming from the rapid growth of population and economic and recreational activities within the region have been met largely through development of new supplies. This strategy is becoming increasingly costly. Projects under consideration in California, for

― 82 ― example, suggest it will cost several hundred dollars per acre-foot to increase water supplies for offstream use, and implementation of these projects would require diverting water from valuable instream uses. Groundwater also has become increasingly expensive due to rising pumping distances and energy prices. Furthermore, the opportunities for expanding groundwater use are limited, especially in the areas with the best agricultural potential; current use already results in the mining of more than 22 million acre-feet per year from western aquifers.[1] The transition to conditions of water scarcity has been under way for several decades in some areas of the West. In the 1950s western water supplies were sufficient to support a rapid growth of use. Total water withdrawals for all but hydroelectric generation rose 56 percent or 4.6 percent per annum from 1950-60. In contrast, withdrawals rose only 15 percent or 1.4 percent per annum from 1970-80. Much of this recent growth occurred in the northern plains states of Kansas, Nebraska, and North and South Dakota, where withdrawals nearly doubled over the last decade. In the rest of the West water withdrawals rose only 0.9 percent per annum in this period.[2] Irrigation spurred by the availability of inexpensive water and energy was the dominant factor in the expansion of western water use. Currently about five of every six gallons withdrawn and nine of every ten gallons consumed go for the irrigation of nearly 50 million acres in the seventeen western states.[3] But as both the largest and a relative low-value user, irrigation is the sector most directly affected by the changing water situation. Some of the impacts of the transition already are becoming evident. Nonagricultural

water consumption in the West grew twice as fast as irrigation use from 1960-80. In areas where water has become particularly scarce and expensive, water for irrigation has started to level off or even decline. In Arizona, for example, total water consumption declined by about 6 percent from 1970-80, even though consumption for nonagricultural uses rose by 67 percent. Only in the northern plains did the growth of water consumption for irrigation exceed the growth for other uses during the last decade.[4] The early expansion of irrigation relied almost exclusively on diverting surface waters. Since the mid-1950s, however, groundwater has accounted for virtually all of the net increase in irrigation water withdrawals. Total surface water withdrawals for irrigation have not increased significantly from the level of 88 million acre-feet (maf) reached in 1955. Groundwater

― 83 ― withdrawals, on the other hand, rose from 11 maf in 1945, to 31 in 1955, and to 56 in 1975.[5] Nearly 40 percent of total irrigation withdrawals now come from groundwater. As a result the aquifers in some of the principal irrigated areas are being depleted, and millions of acres now depend on a diminishing supply of water. The overall growth of groundwater use already has slowed markedly, and in some areas has become negative.

Future Changes in Water Use Demand for western water continues to grow as new investment and people are attracted by the region's mineral, energy and amenity resources. But as supplies fail to grow apace, the competition for water intensifies. In areas of scarcity, irrigated agriculture will increasingly be the sector that others look to for water to meet their growing demands. Water is transportable, but the costs are high in relation to its value in agriculture. Consequently, irrigators in a given area must rely largely on water currently available either naturally or through water importation structures already in place. And as water demands in other sectors grow, irrigators will be confronted with increasingly attractive opportunities for transferring their water to other uses.

Assumptions and Projections of the Second National Water Assessment The Second National Water Assessment provides a useful starting point for examining the implications of future development forces on the allocation of western waters. The Assessment provides water use estimates under average and dry year conditions for a base year 1975 and projections for 1985 and 2000 based on a consistent set of assumptions regarding national growth and change. Principal assumptions underlying the Assessment's

National Future projections include:[6] · National population will grow at slightly less than 1 percent per year and will reach zero growth early in the next century. There will be 268 million people by the year 2000. · Gross National Product will increase at about 4 percent per year.

― 84 ― · Attainment of water quality goals and higher water costs will improve water use efficiency. · Agricultural production and marketing will reflect 1971-73 trends in per capita consumption and export levels. · Fish and wildlife and recreation needs will continue as they have in the past 10 years. Table 3.1 indicates projected changes in population, employment, cropland harvested, and irrigated farmland from 1975-2000 for each of the seventeen western states.[7] These numbers, which have been converted from subregional data in the Assessment to state boundaries, contain some real surprises. In contrast to recent experience, western population and employment are projected to lag behind national growth. Higher than average population growth is projected for the southwestern states of Arizona, California, and Nevada, but population is projected to actually decline over the rest of the century in five northern states. In Wyoming, one of the fastest growing states in the 1970s, both population and employment are projected to decline by more than 10 percent. It is hard to imagine what might cause such a drastic change in regional growth trends (perhaps a complete collapse of energy markets); as noted below, some of these assumptions raise questions about the usefulness of the Assessment's water use projections. The projected changes in western irrigation are more in line with past trends and expectations even though, as discussed later, the Assessment likely understates the level of irrigated acreage. The 10 percent increase in irrigated acreage from 1975-2000 suggests a continuation of the decline in the rate of growth of western irrigation that has been under way for several decades. Irrigated acreage is projected to decline in Arizona, Nevada, New Mexico, and Texas, all of which are faced with major problems of groundwater depletion.

Table 3.2 presents the projections (derived by converting the Assessment data to a state basis) of water consumption for irrigation and other uses. Western water consumption from 1975-2000 is projected to increase only 6 percent for irrigation, compared to 88 percent growth for all other uses. In view of irrigation's dominance as a user of western water, total consumption increases only 13 percent in the West, less than half of the national average.

― 85 ―

Table 3.1 Projected Percentage Changes in Selected Socioeconomic Factors Affecting Water Use, 1975-2000 State and Region

Population

Employment

Cropland Harvested

Irrigated Farmland

Arizona

36

42

2

–12

California

26

36

–1

16

Colorado

21

27

39

2

Idaho

–9

–2

15

14

Kansas

0

0

34

38

Montana

–13

–14

12

44

Nebraska

3

4

–2

19

Nevada

47

48

52

–7

New Mexico

2

12

8

–15

North Dakota –16

–16

28

145

Oklahoma

14

22

28

4

Oregon

16

20

24

20

South Dakota –8

–12

10

74

Texas

18

24

25

–17

Utah

16

25

20

1

Washington

10

22

–4

42

Wyoming

–13

–11

22

8

Western States

Total National Total

18

29

18

10

22

33

19

15

Source: Oak Ridge National Laboratory, State Water Use and Socioeconomic Data Related to the Second National Water Assessment, prepared for the U.S. Water Resources Council (Oak Ridge, Tenn., 1980).

― 86 ―

Table 3.2 Water Consumption for Irrigation and Other Uses by State, 1975 and 2000 Millions of Gallons Per Day 1975

Percent Change 2000

1975-2000

State

Irrigation All Other

Total

Irrigation All Other

Total

Irrigation All Othe

Arizona

3,888

426

4,314

3,590

663

4,253

–8

56

California

23,917

2,184

26,101

25,831

3,327

29,158

8

52

Colorado

5,143

267

5,410

5,408

583

5,991

5

118

Idaho

4,891

143

5,034

5,483

259

5,742

12

81

Kansas

2,548

291

2,839

2,972

567

3,539

17

95

Montana

2,780

172

2,952

4,646

257

4,903

67

49

Nebraska

5,882

233

6,115

6,662

369

7,031

13

58

Nevada

1,694

120

1,814

1,854

176

2,030

9

47

New Mexico 2,396

250

2,646

1,993

328

2,321

–17

31

North Dakota

129

99

228

354

208

562

174

110

Oklahoma

881

365

1,246

846

683

1,529

–4

87

Oregon

3,081

145

3,226

3,833

415

4,248

24

186

South Dakota

292

88

380

593

163

756

103

85

Texas

13,960

1,936

15,896

10,558

4,579

15,137

–24

137

Utah

1,787

262

2,049

1,754

423

2,177

–2

61

Washington 3,149

389

3,538

3,844

941

4,785

22

142

Wyoming

121

2,804

3,355

166

3,521

25

37

17 Western 79,101 States

7,491

86,592

83,576

14,107 97,683

6

88

U.S. Total

18,560 104,677 92,313

2,683

86,117

40,702 133,015 7

119

Source: Oak Ridge National Laboratory, State Water Use and Socioeconomic Data Re the Second National Water Assessment, prepared for the U.S. Water Resources Coun Ridge, Tenn., 1980).

― 87 ― The relations between water scarcity and growth implied in the data and projections of the Second National Water Assessment can be examined for water resource regions and subregions, the geographical areas for which water supply data are provided. These regions and subregions are defined according to drainage basins which do not conform to political boundaries. Regions 9 to 18 and their 53 subregions are used as a proxy for the seventeen western states in the subsequent analysis. Water scarcity (measured as the ratio of total water use in the 1975 base year to average year streamflow) is negatively correlated (at a 95 percent confidence level) with the Assessment's projections of the growth of irrigated

acreage by water resource subregion. Nevertheless, the Assessment's projections of population, employment, and total earnings by subregion are positively correlated (at a 90 percent confidence level or better) with this water scarcity measure. These results suggest that the features that attracted people in the past and contributed to the pressures on water supplies will continue to give these areas faster than average overall growth in spite of the pressures on their water supplies. The water to support the fast overall growth of these subregions, however, will come at least in part from a slower than average or in some cases negative growth of irrigated agriculture. In examining the implications of water scarcity on water use by function, it is nearly as instructive, and conceptually much simpler, to differentiate between just two areas—a water-scarce area and the rest of the West— rather than to consider 53 different subregions. A water-scarce area of twenty subregions (identified in Figure 3.1 and in the note to Table 3.3) has been selected for this purpose. In all twenty of these subregions, 1975 water use exceeded average year streamflows. Most of these subregions also have relatively high ratios of groundwater mining to consumption; mining is 10 percent or more of consumption in sixteen of the subregions, and 25 percent or more in twelve of them. Estimates of instream use have an important impact on the perception of water scarcity. In thirty-three of the western subregions, the instream flows needed to maintain fish and wildlife populations are more than half of the Assessment's estimates of total water use in 1975. The benefits that accrue from instream flows are difficult to measure, and there is no consensus as to how much water should be allocated to these uses. This does not mean, however, that instream benefits are insignificant.

― 88 ―

Figure 3.1 Twenty Water Resource Subregions with Serious Water Supply Problems (cross-hatched area)

― 89 ―

Table 3.3 Sectoral Water Consumption Estimates for 1975 and Projections for 1985 and 2000 Water Use (thousand acre-feet per year) 20 Water-scarce

1975

1985

2000

subregionsl Irrigation

53,553

51,953

50,539

Livestock

559

629

730

Steam electric

234

606

1,294

Manufacturing

372

486

775

Domestic

1,792

2,009

2,284

Minerals

974

1,163

1,332

Other

926

1,015

1,144

Total

58,410

57,861

58,098

Irrigation

35,246

43,129

43,466

Livestock

769

974

1,077

Steam electric

233

785

2,075

Manufacturing

1,365

2,112

3,733

Domestic

1,525

1,695

1,929

Minerals

562

652

790

Other

997

1,202

1,567

Total

40,697

50,549

54,637

Irrigation

88,793

95,082

94,005

Livestock

1,328

1,604

1,808

33 Other subregions2

Totals for water resource regions 9-18

Steam electric

467

1,391

3,369

Manufacturing

1,737

2,598

4,508

Domestic

3,317

3,704

4,212

Minerals

1,537

1,814

2,121

Other

1,923

2,216

2,710

Total

99,102

108,409

112,733

Note: National future data for average water supply conditions. Source: U.S. Water Resources Council, The Nation's Water Resources, The Second National Assessment, vol. 3, app. II (Washington, D.C., GPO, 1978), table II-4. 1

This water-scarce area includes the following water resource subregions: 1007, 1010, 1102, 1103, 1105, 1106, 1203, 1204, 1302, 1303, 1304, 1305, 1502, 1503, 1602, 1603, 1604, 1803, 1806, and 1807. 2

The 33 other subregions are calculated as the sum of water resource regions 9 to 18 minus the 20 water-scarce subregions.

― 90 ― On the other hand, provision of many instream benefits need not be competitive with offstream uses. For example, the better recreational areas in the West often are in the upper reaches of the streams. Streamflows can be maintained in these areas for withdrawal downstream where the better agricultural lands are often located. Thus, adding instream uses measured at the outflow point of a subregion and offstream consumption may overstate a region's water use. Nevertheless, even when instream uses are ignored— which few people would advocate—water problems remain. Offstream consumption alone is equal to, or greater than, average streamflow in seven of the water-scarce subregions. And 1975 water consumption exceeded dry year streamflow (the natural flow that will be equaled or exceeded 80 percent of the time) in all the water-scarce subregions identified in Figure 3.1.

Projections from the Second National Water Assessment suggest that while total water consumption will be essentially constant within the water-scarce region over the last quarter of the century, the allocation of water among types of users will shift. According to the projections, a decline of nearly 6 percent in consumption for irrigation is expected to slightly more than offset the 56 percent increase in consumption for all other uses (see Table 3.3). But even after this reallocation of supplies, irrigation will remain the dominant water user, accounting for 87 percent of consumption in the year 2000. In contrast to the outlook in the twenty water-scarce subregions, there are opportunities for expanding both total and irrigation water consumption in the rest of the West for at least another decade. Indeed, the Second National Water Assessment projects that water consumption in the remaining thirty-three subregions will increase 22 percent for irrigation and 36 percent for other purposes between 1975 and 1985. Only a very minor further expansion of water consumption for irrigation is projected for after 1985, but consumption for all other uses is projected to increase 50 percent over the last fifteen years of the century. The twenty-five year projections for these thirty-three subregions suggest total water consumption will rise by one-third and consumption for purposes other than irrigation will more than double.

Limitations of the Projections in the Assessment The Second National Water Assessment is the only recent attempt to systematically examine the nation's water use and supplies. But, as alluded to above and as considered in some

― 91 ― detail below, there are good reasons for questioning some aspects of these projections.

Water for Energy Although nonagricultural demands on western waters have been relatively minor in the past, development of the West's vast energy resources, especially coal and oil shale, may alter that. While water consumption projections of the Second National Water Assessment include an allowance for steam electric production, petroleum refining, and fuels mining, there was concern that the Assessment had not taken adequate account of all likely energy developments and associated water requirements. This concern led to a supplementary study by Aerospace Corporation, which accepts all the Assessment's water supply data and all the demand projections except

those relating to energy.[8] From four federally generated energy development scenarios, the maximum feasible limits for energy development are determined along with associated water requirements, assuming standard size plants and no special provisions to adopt water-conserving technologies. Although these estimates are higher than any likely levels, they provide an upper bound to the demands energy development is likely to place on western waters. In comparison to the Assessment projections presented in Table 3.3, the high projections of water for energy development in the Aerospace report increase nonirrigation water consumption levels by 7 percent as of 1985 and 39 percent as of 2000. These estimates represent a 1 percent increase in total western water use by 1985 and a 6 percent increase by 2000. Although the percentage changes for the West are modest, the impacts would be localized, and within the affected regions major new demands on water supplies are implied. Where demand already exceeds renewable supplies, any increase requires either compensating reductions among other users or additional groundwater mining. The twenty water-scarce subregions account for about 47 percent of the consumption of water for energy projected for the turn of the century in the Aerospace report. In the absence of compensating adjustments by other users, this would increase energy uses to about 8 percent of this area's total water consumption. Water for energy would become particularly important in seven of these subregions, where energy uses would account for an average of 19 percent of total projected water consumption.[9] If these energy projections are realized, irrigation

― 92 ― certainly would be adversely affected. The Second Assessment had already projected that irrigated acreage in these seven subregions would decline from 16 percent of the West's total as of 1975 to 10 percent in 2000.[10] The percentage might drop further if the higher energy water use levels are realized. The Aerospace projections suggest that energy uses could become an even more important component of water consumption in some of the subregions where water currently does not pose such constraints to development. In nine of the other thirty-three western subregions, the combined energy uses of water account for an average of 35 percent of total projected offstream water use in 2000.[11] In general, however, these nine subregions do not rank among the more important irrigated areas; they are projected to account for only 6 percent of the water consumption and 4 percent of the land for irrigation in the West by 2000.

Alternative Population and Water Use Projections The data and projections presented above as the Assessment view are the product of the federal attempt to develop nationally consistent information on current and projected water use. They are known as the National Future (NF) estimates. But for some of the regions and some of the socioeconomic and water use variables, an alternate set of information is also presented in the Assessment. A study team representing state and regional perspectives was formed for each of the 21 water resources regions, and these teams developed State-Regional Future (SRF) estimates for their respective regions. The SRF projections are not comprehensive, nor are they based on a consistent set of assumptions as to the national growth. Yet, as the Assessment points out, they do reflect a more localized and perhaps more accurate view of regional and subregional conditions.[12] There are some striking differences between some of the NF and SRF projections of population growth and water use that raise questions about the accuracy of the National Future estimates. The SRF projections suggest a national population (including the Caribbean area) of nearly 284 million by 2000, nearly 6 percent more than the NF projection. While the NF figure is closer to and actually slightly above the Census Bureau's mean estimates of total population in 2000, the regional distribution of the NF projection is questionable. Virtually the entire difference between the alternative population projections in the Assessment is attributable to the lower NF projections for the western water resource regions. Despite the fact that

― 93 ― population in the seventeen western states grew at more than twice the national average from 1974-79,[13] the NF data project lower than average population growth for the West as a whole from 1975-2000 (see Table 3.1). This inexplicable result suggests that the NF data may understate the future demands for western water. The NF estimates of irrigated acreage in the West are also much lower than the SRF estimates in both the 1975 base year (40.6 versus 46.2 million acres) and in 2000 (44.9 versus 61.3 million acres). While there is considerable uncertainty as to the amount of land under irrigation, it is likely that the NF data grossly understate irrigated acreage in the base as well as in future years.[14] For instance, the National Resources Inventory estimate of 50.2 million acres irrigated in the West in 1977 is 24 percent above the 1975 NF estimate and 9 percent above the 2000 NF estimate.[15] The impact on water use estimates of understating irrigation levels is unknown. But again there is a possibility that the NF projections understate the competition for western water resources.

In view of the differences noted above between the base year levels of irrigation and the projected changes in western population and irrigation, it is not surprising that the NF and SRF estimates of water use also differ. The SRF estimates of total water consumption in water resource regions 9-18 are lower in the base year (84.7 versus 88.5 billion gallons per day) but considerably higher by the year 2000 (120.7 versus 100.7 billion gallons per day) than the NF projections. In both years, water consumed in irrigation accounts for more than 90 percent of the differences between the two sets of data.

A Case Study: The Yampa River Despite the reservations about the projections of the Second National Water Assessment, these data do indicate the broad changes in water scarcity likely to emerge from the increasing competition for western water and the implications of these changes on major categories of water users. These data, however, are not sufficiently detailed to provide much insight into local water problems or the nature of the competition for water. Indeed, there may be serious conflicts over the use of a region's or subregion's waters not revealed by the Assessment's aggregate supply and consumption data. Changes which have only

― 94 ― marginal impacts on the overall level of western irrigation may have dramatic impacts on local areas, even within regions and subregions where water does not appear in the Assessment as being particularly scarce. These points are illustrated in the following discussion of the Yampa River, a tributary of the Green River which in turn is a tributary of the Colorado River.[16] The Yampa River is celebrated for its beauty and is a prime sports fishery. It also contains abundant resources of coal and is being considered for possible energy development. To assess the effect of energy and fuel production on the Yampa River flows at Maybell, Colorado (USGS gauging station 2510), scenarios were assumed for 1990. A. 2,000 Mw thermal electric power plant using 6.7 million tons of coal per year; the remainder of the 24 million tons per year of coal mined shipped out of the basin by unit train. B. 2,000 Mw thermal electric power plant; 250 million standard cubic feet per day coal (SCFD) gasification plant using 6.94 million

tons of coal per year; the remainder of the 24 million tons per year of coal mined is shipped out of the basin by unit train. Details of these two energy development scenarios are presented in Table 3.4. For assessing the water consumed in these two scenarios, a "base case" plant and a "complete" plant are considered for both the power plant and the coal gasification plant. The "base case" represents a situation in which no restrictions are placed on waste discharges to the environment; the "complete" plant, a situation where zero wastewater discharges are allowed. As shown in Table 3.4, the two energy development scenarios, plus the "base" and "complete" plant options for both the thermal power plant and the gasification plant, result in six possible combinations of water consumption. For these six combinations, the water consumption rates for the year 1990 range from a low of 59.4 cubic feet per second (cfs) (43 thousand acre-feet per year) to a high of 101.3 cfs (73.3 thousand acre-feet per year). The effect of this consumptive use of water on the flow of the Yampa River at Maybell is depicted in Table 3.5. For comparison, energy scenario B with "complete" plants for both the thermal power and coal gasification facilities was assumed (scenario B4 in Table 3.4). This consumptive use of water is compared with the mean annual flow, the mean monthly flows, and various measures of the low flow in the Yampa River at Maybell, Colorado. It is clear from Table 3.5 that energy development

― 95 ―

Table 3.4 Consumptive Use of Water in the Yampa River Basin Under Energy Development Assumptions Energy Development Assumptions Development projection:

1990

Surface mining of coal:

24 million tons/year

Thermal electric power plant:

2,000 megawatts

Coal gasification plant:

250 million standard cubic feet/day

Coal input: Power plant:

6.70 million tons/year

Gasification plant:

6.94 million tons/year

Excess coal:

10.36 million tons/year

(shipped by unit train out of the Yampa River Basin)

Water Consumption Scenarios (cubic feet per second) Scenariosa Al Power plantb —base casec

A2

54.8

B1

B2

54.8

54.8

49.4

complete plantd Gasification plant— base casec

36.5

B3

B4

49.4

49.4

36.5

27.9

complete plantd

27.9

Mining and land reclamation

10.0

10.0

10.0

10.0

10.0

10.0

Total water consumption

64.8

59.4

101.3 92.7

95.9

87.3

Source: Nicholas C. Matalas and Richard Smith, "Yampa River Case Study," paper presented at the Resources for the Future Forum on the Impact of Energy Development on the Waters, Fish and Wildlife in the Upper Colorado River Basin, in Albuquerque, New Mexico, October 1976. a

Scenario A—power plant only; scenario B—power plant plus gasification plant. b

Mechanical draft-cooling towers.

c

No restrictions on waste dischargers.

d

Zero waste discharges (except for condensate).

― 96 ―

Table 3.5 Comparison of Streamflows and Consumptive Use of Water for Energy Development in the Yampa River Basin (USGS gauging station 2510 at Maybell, Colorado) Streamflows (cubic feet per second)

Streamflow at USGS Station 2510

Water Consumption in the Yampa Caused by Energy Developmenta

Net Flow at Maybell, Colorado

Mean annual

1,560

87

1,473

October

343

87

256

November

345

87

258

December

298

87

211

January

272

87

185

February

320

87

233

March

671

87

584

April

2,620

87

2,533

May

6,280

87

6,193

Mean monthly

June

5,540

87

5,453

July

1,360

87

1,273

August

380

87

293

September

241

87

154

1-day

41

87

b

3-day

41

87

b

7-day

45

87

b

30-day

62

87

b

365-day

1,060

87

973

Low flows (10year)

a

Water consumption scenario B4, Table 3.4.

b

Storage will be required for the low flow periods.

― 97 ― could not occur in the Yampa River Basin without surface or groundwater storage, or supplemental supplies from another subbasin. There simply is not enough water for energy and fuel production purposes during the low flow periods. Moreover, tradeoffs with other uses of river waters might have to be made during parts of the year, especially the seven-month period from August through February. Apparently, from this rough analysis of streamflows in the Yampa, the fisheries might be in serious jeopardy if energy development occurs, or hydraulic works might have to be undertaken that many think would adversely alter the character of the basin.

The only way to understand the full implications of energy development is to look at the details of specific situations. Unfortunately, such analyses are seldom part of studies assessing the energy potential of a region. Such studies should have high priority.

Conclusions and Implications for Water Management[en17]Conclusions and Implications for Water Management[17] While the West is not running out of water, it is running out of readily available, inexpensive water. Although some additions to the usable water supplies of the region may be developed either through streamflow augmentation or exploration and development of groundwater, the end may be coming of any large-scale schemes for further diversions of water into the region, or even any sizable shifts of water from one basin to another within the region. Thus, for practical purposes it would seem that the region must accept the limited nature of its water supplies and should move strongly to adapt itself to that condition. The limited nature of water supplies, however, does not absolutely preclude development within the region. Barriers to urban residential or other development are more a matter of social than of physical limitations. Such barriers may be the institutions that prevent the transfer of water from agricultural uses into other, more highly valued, uses; or they may be social insistence on artificially low prices for municipal water. Instead of promoting rigid constraints on water use patterns, political effort within the region should be directed toward increasing the flexibility of current water use practices among all users. Generally speaking, there is considerable opportunity for modification if regional institutions permit and encourage it.

― 98 ― For example, in planning new electrical generation facilities in the San Juan portion of the Colorado River that lies in New Mexico, utilities have available several options regarding the use of cooling water, even though the New Mexico State Engineer has projected a fully appropriated condition for the San Juan Basin without the addition of any new generating facilities. First, technological adjustments could be made in the cooling water required. Second, existing privately held water rights in the basin could be purchased, and with approval of existing authorities this water could be transferred into industrial use from its current predominant use in agriculture. Third, cooling water might be drawn from deep groundwater stocks rather than from currently used surface water supplies. These and other options illustrate the range of possibilities for flexible water use within the region. One general institution that contributes to flexibility is the existence, where

permitted, of an economic market for water rights. Such a market, if it works properly, signals all water users, in the form of the price that a water right may command, that (a) water is available, and (b) that competing demands for its use can be measured. With the information provided by the price signal, current and prospective water users can make informed decisions on water use options. In addition, as the price of water rights increases, there is a strong incentive to conserve water. The economic returns to water used in irrigation tend to be lower than in most other uses. Accordingly, where demand exceeds supply, and institutions permit water to be transferred among sectors, water tends to be bid away from irrigation. Nonetheless, these forces will not necessarily result in large transfers of water out of irrigation. Since irrigation is the dominant offstream use of western water, large percentage increases in other water consumption can be accommodated with relatively small percentage reductions in irrigation use. Furthermore, many new demands can be met without transferring water away from agriculture. Deep or brackish groundwaters generally considered unsuitable for irrigation are available in some areas, and some primary sites for energy development still have untapped surface waters. Thus, even if the Assessment has understated nonirrigation water demands, water transfers among sectors will have only marginal effects on the total quantity of water consumed for irrigation.

― 99 ― Regional irrigation trends initiated several decades ago in response to competition for water will continue. Some decline in irrigated acreage within the area from the southern High Plains to Arizona and Nevada is likely, as nonagricultural users bid water away from irrigation and farmers reduce pumping in response to declining groundwater tables and high energy costs. These declines will be more than offset by continued expansion of irrigation in areas where relatively low cost water is still available. The Nebraska Sandhills area will be one of the few areas in the West that will experience a significant further expansion of irrigated acreage. The overall rate of growth of irrigated acreage in the West will continue to fall over the next several decades, but is not likely to turn negative during this century. Net expansion will depend in large part on agricultural prices. A modest 5 to 6 percent expansion (roughly 3 million acres) of irrigated acreage seems likely if real crop prices remain at roughly their 1975-80 average. A 25 percent increase in real crop prices might stimulate a net expansion of about 15 percent (nearly 8 million acres). In either case, however, the competition for increasingly scarce water supplies should bring the expansion of irrigated land to a halt early in the next century. Principal changes in irrigation will be qualitative rather than quantitative in the coming decades. The quantity of water consumed for agriculture is likely

to peak before irrigated acreage peaks. No peak in irrigated production is likely for the foreseeable future, however. As water costs rise, technologies and management practices that conserve water become more profitable. Since much of the irrigation in the West developed under and continues to be based on very low-cost water, the opportunities for substituting capital, labor, and management skills for water are great, and will be utilized with increasing frequency as water becomes scarce. The potential for such substitutions is illustrated in the High Plains Development Study which concluded that high energy costs would encourage a rapid improvement in irrigation efficiency. Average water use in the Texas High Plains is projected to decline from 1.38 acre-feet per acre in 1977 to 0.68 in 1990. Crop yields, however, are expected to continue to rise throughout the period and beyond.[18] Major constraints on western development over the rest of this century are likely to stem from institutional factors affecting water supply. As noted above, nonirrigation demands for water can be accommodated with only marginal effects on the overall

― 100 ― level of irrigation. But it is by no means certain that water will be transferred to higher value uses on a timely basis, or that farmers will have incentives to make the investments and management changes required for more efficient water use. The institutions, including the legal system, affecting water use were developed when water was plentiful in relation to demand. Often these institutions, which vary widely among states, restrict transfers to alternative uses and discourage conservation measures. To the extent that the competition for water is relegated to the courts and state regulatory agencies rather than the market place, overall western development is likely to suffer. Although such restrictions tend to favor agriculture since irrigators commonly own the most senior water rights, continued development of western irrigation depends on incentives for improving water use efficiency, not on locking water into low-value uses.

Discussion: A.N. Halter The views expressed in this paper reflect the opinions of the author and not the opinions of the Electric Power Research Institute or its members. In this discussion, my comments are divided into two sections. The first follows the outline of the Frederick-Kneese paper from the perspective of the adequacy of the methodologies used, with particular emphasis on water and energy. The second section discusses some of the implications of how pricing structures of electricity affect water use.

Review of Frederick-Kneese Paper In their "Overview" and "Past Changes in Water Use", past trends in water use are shown to be the history of the expansion of irrigation. Growth in irrigation relied on surface water until the mid-1950s, when groundwater took over as the major source of supply. The authors should have pointed out that it was low-cost energy that made it possible to lift groundwater inexpensively. In the authors' description of the projections of the Second National Water Assessment study, the following points should be noted: 1) Although assumptions of population growth are questioned and superficially related to the collapse of energy markets, other than referring to higher water costs and improved efficiency of uses, there apparently is no underlying pricing structure used to make the projections. 2) Frederick and Kneese relate water scarcity to the Assessment's projections of water availability, and projections of population, employment, and total earnings. Negative and positive correlations respectively suggest a methodology was used to make Assessment projections that is naive and devoid of economic dynamics and price structures. 3) Limitations of the Assessment are reviewed by the authors, and the supplemental study by Aerospace Corporation to cover the energy use of water is recounted. Though the authors point out that no special provision is made for including the possible effects of adopting water-conserving technologies,

― 103 ― they do little to convince the reader that a better methodology was used by the Aerospace Corporation than by the Assessment study. They also point out that National Future estimates likely understate the competition for water resources, and are different from those made by the State-Regional Future study. Under the heading of "Conclusions", the authors say that expansion in irrigated acreage in the West will depend in large part on agricultural prices, but do not relate it to energy prices in any general way. Institutional factors are given the major credit for limiting the use of water. This is the usual conclusion from resource studies in which the dynamics of supply-demand interaction are ignored. The current situation in energy speaks loudly for further demand constraint as pricing structures change.

The remainder of the Frederick-Kneese paper presents a case study of the Upper Colorado River Basin and its tributaries, a case that has been overstudied with little variation in the conclusions drawn. The Southwest Region Under Stress Project conducted by the authors' employer, Resources for the Future (RFF), justifies the use of the Colorado River as a case study as the authors are knowledgeable about the region. The RFF study uses a scenario approach to project energy development. The "speculative nature" of this approach is emphasized in that it ignores the price of electricity. The only factors said to affect water consumption in generating stations are the technology, quality of coal, and utilization rate; these in turn are said to be dependent on cost of water and other inputs. Pricing structures on the output or demand side are assumed away by the usual implicit assumption of the fundamental right to electricity and food. Again, institutional changes are emphasized as necessary in the concluding section of the paper. One such change recommended by the authors is an "economic market" for water rights. Supply and demand for water rights would set their price and exchange among users. But the authors do not indicate how such a market would adjust for the inevitable uncertainty in streamflows and consequent shortages of electricity. The cost of electricity outages to the society and the economy are not considered in a water rights market. The lack of a holistic approach to institutional development can be just as detrimental to water

― 104 ― allocation as the partial analyses used for making forecasts of water consumption. One must question the methodologies being used for planning water resource use. In most cases the methods are so unclear that one must ask: what is the methodology for long-range forecasting for water and/or energy? Do forecasts reflect only conventional wisdom and the subjective preferences of the experts and institutions doing the planning, rather than the dynamics of interactive components in society and the economy? Does longrange planning for water, rooted in long-range forecasting of energy demand, rest on shaky ground? Under foreseeable conditions, especially changing costs, associated prices, and rate structures, demands are very likely to depart from patterns of the past.

Impacts of Electricity Price Structures on Water Use Since I have emphasized that resource studies and long-range planning studies for water must be necessarily rooted in some expected schedule of prices for outputs and inputs, it is only appropriate that I also point out the impacts on water use of different pricing structures for electricity.

Prices for electricity are influenced not only by prices of petroleum, but also by utility regulation and rate structures. The unfortunate aspect of averagecost pricing, imposed by a 100-year-old regulatory environment, is that consumers do not experience the full cost of new sources of energy and hence of electricity. At a later time when prices must inevitably rise, many users of electricity are stuck with equipment and facilities required on the basis of former conditions. This can only lead to even more inefficient use of water. The water resource planner can no longer ignore the consequences of faulty regulation of the electric utility business. Clearly, electricity conservation and peak-load pricing affect the amount of water and its pattern of use in irrigation. Declining block-pricing structures for electricity formerly created an incentive for groundwater overdrafting, because it was cheaper per unit to lift larger quantities of water. New inverted blockrate structures will remove that incentive, and should help to reduce the problem of overdraft. Another innovative pricing structure being studied by energy economists and likely to be adopted by the electric utility industry is "responsive" pricing. As the term implies, electricity is priced essentially instantaneously as it is produced at its marginal cost. The communication and computer technology is already

― 105 ― available to implement this for large users such as water districts, industrial firms, and municipal institutions. This time-of-use pricing structure would have a profound impact on water use in agriculture, as well as in industry and public institutions. The proper pricing of electricity for the major share of users would allow the simplest of rates to be used for residential customers. The confusion being caused by the proliferation of rates for residential customers is unfortunate and unnecessary, leading to further mistrust of electric utilities and the misallocation of energy and water. The uncertainties of supply of electricity, given any pricing structure, must still be dealt with. The institution of a simple buy-back scheme could eliminate the consequences of shortage in an economic manner. The buyback scheme could be similar to the one used by airlines to buy back seating when there is overbooking of a flight. A similar institution in the water area would complement the Frederick-Kneese suggestion of a water rights market.

Discussion: Robert R. Curry This paper does a good job of assessing the inadequacies of the U.S. Water Resources Council's report, The Nation's Water Resources 1975-2000: The Second National Water Assessment. However, many factors of supply and competition are not considered in either this paper or the Second National Assessment. Some of these are reviewed briefly here. Groundwater availability is a serious problem, and groundwater quality is fast becoming equally serious. Technologic solutions are adequate for the short run, but when considered in a 25-50 year time frame, are probably worse than no solutions. As Frederick and Kneese point out, about 40 percent of western irrigation water is presently derived from groundwater, and five out of every six gallons withdrawn from the ground is used for irrigation. Further, of 56 million acre-feet withdrawn (estimated) in 1975, 22 million are overdrafted in excess of safe yield (mined). The authors further point out that, in half of the western watershed subregions, fully 50 percent or more of the consumption is derived from overdrafted groundwater. Groundwater law and the public institutional framework are archaic throughout the West, and in many cases are based upon wholly faulty assumptions and models of groundwater dynamics.

― 106 ― Thus, even in the most progressive states, water developers are encouraged to recover water with high energy costs from deep aquifers with poor water quality that will ultimately damage both surface soils and aquifers. In most cases the damage is irreparable. Particularly damaging is saline seep, which is an agricultural artifact of dryland farming techniques used in northern plains states. It renders unproductive tens of thousands of acres of agricultural land annually, at a rate far exceeding strip-mining, highway construction, and urban sprawl combined in those areas. Salt loading and destruction of soil structure and ultimate productivity is a concomitant of use of sodic saline water for agriculture. We are often told of the great advantages to be gained by development of salt-tolerant food crops and forage. While it is certainly possible to increase productivity even while utilizing water of declining quality, such technology has a very discrete and finite limit, beyond which sodic loading will render the site essentially nonproductive. The progressive character of such actions means that we must ultimately pay the cost for myopia. Groundwater pollution is another area of grave concern. Many of our

assumptions about future groundwater supplies for all uses assume that known high-quality groundwater reservoirs will remain usable. We are learning, however, that the publicized horrors of Love Canal are but a small localized example of a much more pervasive nationwide problem.[1] As cataloged by the Environmental Protection Agency, landfill and other sources of contamination have set serious limits on the period of time for which we may reasonably expect to recover groundwater from many significant and important local aquifers. Thus, even though we may not exceed safe yield pumping, we may have a limited lifetime for aquifers before we begin recycling our own wastes into domestic supplies or agricultural soils. Our projections of water supplies assume that supplies presently potable will remain so, despite saline intrusion, aquifer mixing, contamination through mineral extraction, industrial surface and groundwater pollution, and leachate contamination. The non-reversibility of such contamination seems to have escaped most analysts. Groundwater overdraft is also a serious problem not clearly addressed. While we may estimate safe yield and overdraft rather precisely, in fact we know very little about site details. It is actually very difficult to estimate overdraft. Since agriculture itself, particularly salt-tolerant agriculture, and other land uses

― 107 ― all tend to impede surface water infiltration through the root zone into the groundwater reservoirs, most observed overdraft is not a linear function of rate of withdrawal. Other things being constant, overdraft tends to increase with a fixed withdrawal rate, particularly where new lands are being brought into production and being urbanized. Thus, linear projections probably underestimate the true situation for the year 2000. Energy costs are an increasingly important factor in water costs. Analysis of competition for western water requires careful attention to the economic pricing and institutional factors governing costs of water and electricity. As more and more water is delivered at costs of several hundred dollars per acre-foot, as in the California Water Project, many forms of agriculture are unable to afford additional water. What this has meant in California is that only large-scale corporate farms occupying large acreages of previously marginal land of questionable long-term productivity, and growing specialized high cash-yield crops, can afford to compete with urban and industrial water needs in a quasi-open market. As Frederick and Kneese point out rather inadequately, the cost of electricity is an increasingly important factor in groundwater costs. But several other energy cost factors are equally important. The cost of energy is increasingly important in all water supply systems, particularly those utilizing offstream storage, large storage reservoirs of any sort, or extensive conveyance structures. There is also feedback between the rising cost of electricity and cost of water for irrigation. As irrigation costs increase and food costs follow, it becomes

economically feasible and desirable to store and transport higher cost food commodities. This means that an increasing fuel resource is utilized in food production and distribution, thus increasing competition for fuels for electricity production. Finally, there is critical social disruption caused by increasing supplies of high-cost agricultural water. This is well illustrated in the San Joaquin Valley of California, where high-cost federal and state projects deliver water to new sites for large, highly capitalized and mechanized farms. These large-scale operations, using expensive water on sites with drainage problems, salt loading, or poor soils, can temporarily compete with small family farms that have long-established food production systems often using gravity-feed streamflow irrigation sources or other lowcost riparian rights. The economic competition damages a diverse, efficient, long-productive food growing system in favor of a short-lived, high energydependent, unstable system. Thus pricing and delivery

― 108 ― institutions destroy a long-term resource base for short-term production gains. Regional autonomy also declines as large-scale water delivery systems increase. Ultimately, rising energy costs will preclude continued production on the energy-dependent sites, but the low-energy-demand sites will meanwhile have been lost to urbanization, or their gravity water rights sold for other purposes. Long term climatic change is a final factor that must be considered in a thorough evaluation of water resource demands. As pointed out by Harold Fritts in Chapter 1, the "historic" record of climate, including runoff and precipitation, leads to considerable overestimation of future resources. Study of tree-ring or other paleoclimatic records suggests that our concepts of drought used in present planning are rather naive. The unusual 20th century moderate climate cannot be expected to persist.

PART II— ALTERNATIVES FOR SATISFYING AGRICULTURAL WATER DEMANDS Chapter 4— Developing New Water Supplies by Harvey O. Banks, Jean O. Williams, and Joe B. Harris

Abstract The inadequacy or maldistribution of water supplies for agricultural and other water users throughout most of the western U.S. has historically been a focus of attention for the local citizenry, for water planners and developers, engineers, conservationists, economists, promoters and others concerned with the future of the region. This paper looks at the potential for developing alternative water supplies for the region, with special emphasis on meeting the future water needs of the agricultural sector. Prospects for importing excess surface waters into the region, either from international or domestic sources, are examined along with several local water enhancement or augmentation potentials. Weather modification, water harvesting/water banking techniques, desalination and/or use of saline water supplies, water Reclamation and reuse, surface/groundwater management, improvements in operation of existing projects to increase yields, and other prospects for local water supply enhancement are discussed. General conclusions are that the probabilities for large-scale new water supplies or developments for the region in the foreseeable future are not great. The potentials for significant breakthroughs in local water supply enhancement or any large-scale water importation for the semiarid West are limited.

Development of irrigated agriculture in the semiarid to arid regions of the Great Plains, the Southwest, and the far western states was an inevitable step in the westward growth in the United States. Given the physical conditions of the availability of land, deep, productive soils, advantageous terrain, and climate that appeared to be suited to large-scale dryland farming, the agriculturally oriented culture of the western expansion quickly established an economy of boom-and-bust dryland farming. Early reclamation programs demonstrated the potential for irrigation in these vast western lands. When, in the 1930s, deep

― 110 ― wells became more feasible and economic, extensive drilling tapped what were apparently unlimited groundwater resources, and irrigation spread rapidly throughout the Plains states, the Southwest, and wherever the combination of good land, favorable climate and cheap, plentiful water supplies could be found. Irrigation expanded even more rapidly after World War II. By the 1960s, it had become apparent that groundwater resources were being depleted. Commitments of surface water to irrigation through reclamation projects came under increasingly heavy fire from existing or potential competing water users. More sensitive environmental concerns were also expressed. Throughout the West, a critical water supply crisis was developing. Thus, water planners and developers, economists, politicians, and citizens concerned with the future have turned their attention to the potential for developing new water supplies. Simultaneously, the options for improving the efficiency of use of existing supplies have been subjected to intense study, as is reflected in other chapters of this volume. This chapter deals with the prospects for developing new or augmented water supplies. There are relatively few new water resources in the West remaining to be developed. The prospects of developing those are slight and the costs would be very high. There are, however, opportunities for better allocation of supplies from existing projects, for improvement in management of such projects, for intervention in the hydrologic cycle to modify precipitation events on a basis more nearly related to man's needs than nature provides, and for application of some of the newer technologies. With that understanding, we will look briefly at the potential for new or augmented water supplies for irrigation in the West.

Imports from Outside the United States Both Canada and Mexico share borders with the United States, and across those borders occur common problems of matching water needs with available supply. Yet within the continent of North America vast quantities of surface water occur, and the developable yield of all of those resources could meet the needs of all three nations for the foreseeable future, if it were possible to develop, allocate, manage, and use the water in the common interest. Realistically, the difficulty of this coordination, while

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not insurmountable, is awesome, particularly as regards the political/legal/institutional/financial aspects. Within our own United States, discussions of interbasin transfers of water within a state or between and among states are generally conducted with a great deal more heat than light, and often with extraordinarily slow results. While international development and allocation of available water resources may be difficult and very long-term in prospect, they are not impossible, and in most cases could be shown to be mutually advantageous for each nation and regional (or basin) participant. One of the axioms of any water transfer proposal is that there must be demonstrable benefits for all parties—both importers and exporters. But let us look at some of the international potentials that have been examined. These international water transfer schemes are highly conceptual and typically have been investigated at only reconnaissance levels of feasibility. Water development sites and facilities have not been identified specifically, nor have meaningful cost projections been prepared. Projected future costs in excess of $100 billion for complete system installation could be anticipated. Looking first to the case of Canada, we here give brief discussions of four proposals for moving water from Canada to the United States.

The Rocky Mountain Plan[en1]The Rocky Mountain Plan[1] The Rocky Mountain Plan, conceived by William G. Dunn, Consulting Engineer, is a potential massive, international water and power development project that would distribute water and power throughout the West from Canada to the Mexican border. Principal sources of water are the Peace, Athabasca, and Smoky rivers in northern Alberta (Canada), and upper tributaries of the Mackenzie River in northern British Columbia, which flows into the Arctic Ocean. Additional sources of water are the Kootenai and Flathead rivers and Clark Fork in western Montana, which are upper tributaries of the Columbia River. Water would be diverted for use within the Yellowstone, Missouri, and the Snake rivers in the northwestern United States, and upper tributaries of the North and South Saskatchewan rivers in Alberta. The water distribution system would include several large reservoirs with a total storage capacity of nearly 100 million acre-feet. Project yield would range from 12 to 25 million acrefeet per year, depending on aqueduct and reservoir sizing. This water would be distributed through more than 5,850 miles of

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aqueduct for use in southern Alberta, Montana, Idaho, Wyoming, all of the western states on both sides of the Rocky Mountains including west Texas and California, and northern New Mexico in the Colorado River and Rio Grande valleys. New energy developed under the Rocky Mountain Plan would come from a huge hydroelectric project called the Whitehorse-Skagway Division, collecting water from the upper tributaries of the Yukon River and releasing it through a 2,200-foot power drop into an interior inlet of the Pacific Ocean near Skagway, Alaska. The 33 billion kilowatt hours of power produced by this system would be conveyed in a 2,000-mile transmission line to Alberta, British Columbia, and the Pacific Northwest for general use in the power market, and for project purposes. Three large storage reservoirs with a total storage potential of 60 million acre-feet are proposed within the Columbia River Basin. These reservoirs would include large pumped storage facilities that would reregulate the power developed in the Columbia River plants and in the project power plants, and that also would produce some new power. The entire Rocky Mountain Plan, including power facilities, was estimated to cost between $40 and $50 billion in 1977 dollars. One of the significant advantages of the Rocky Mountain Plan is that it could be staged to provide significant water and power benefits during early development.

Canadian Proposal Three Canadians (Knut Magnusson, Edward Kuiper, and Roy E. Tinney) have proposed concepts for diverting waters from the Athabasca, Peace, and Laird rivers to be conveyed across the plains of northern Alberta, Saskatchewan, and Manitoba to the United States border in North Dakota. A full report on this conceptual plan was not available to the authors, but it is of interest, showing as it does the international concern with such possibilities.

North American Water and Power Alliance (NAWAPA)[en2]North American Water and Power Alliance (NAWAPA)[2] NAWAPA is a master plan concept that proposes taking advantage of the geographical and climatological factors of the North American continent in contrast to the single river basin plan. It would utilize the excess water of Alaska, the Northwest Territories, and the Rocky Mountain regions of Canada, and distribute it to the water-deficient areas of Canada, the United States, and northern Mexico.

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NAWAPA, conceived by the Ralph M.Parsons Company, includes a possible Transcontinental Canal for Canada—a navigable waterway from Alberta to Lake Superior. The canal system, plus the development of rivers in north central Canada, would distribute irrigation water across the plains and increase the flow through the Great Lakes-St. Lawrence System to alleviate water pollution and lowering water levels of that area. The NAWAPA plan is projected to generate 60 to 180 million kilowatts of electric power (net after meeting its own needs), and to supply more than 75 million acre-feet of water annually. The cost to implement the entire NAWAPA concept is estimated at several hundred billion in current (1982) dollars, with spending spread over a 30 to 50-year period.

Western States Water Augmentation Concept[en3]Western States Water Augmentation Concept[3] This plan, proposed by Lewis Gordy Smith, is for a new water system that would permit any available surplus waters from the Fraser River near Hope, British Columbia, and from the Coastal Range in British Columbia to be passed into the Columbia River, and from there conducted within a distribution system both east and west of the Continental Divide. This system would supply water to the Upper Snake, the Humboldt River system of Nevada, the Salt Lake area, the Missouri River system, the Green River and the lower Colorado, the Rio Grande below Albuquerque, and the entire High Plains extending from Nebraska to western Texas. The plan would also look to the ultimate possibility of extending to the far north, to sources of British Columbia, Yukon, and Northwest Territories of Canada, and of later placing this water in the initial water conveyance system within the United States. For the entire collection system from the Dean River to the Columbia, Smith projected a total of 26 dams, ranging in height from 200 to 1,200 feet, costing some $6.3 billion (1967 dollars). Approximately 26 power and pump plants would be required, with total pumping load and power generation potential about balanced. Almost 55 miles of open canal and five main tunnels totaling 56.5 miles, with capacities ranging from 5,500 to 49,000 cubic feet per second would be needed. The above features, along with transmission system, some railway relocation, and miscellaneous structures, would call for a total expenditure of about $11.5 billion in 1967 dollars. In addition to these proposals for moving Canadian water across international boundaries, some planners have discussed the potential of moving water from northern Mexico into the

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United States. These proposals have included capture and transfer of flood waters from the Rio Conchos in northwest Mexico and other potentials along the Mexican eastern coastal area. None of the discussions have been formally considered or presented.

Interstate Diversions of Water Interbasin diversions of water have been in place in many parts of the United States for many years. Rarely have they been carried out without controversy. Where such diversions are contemplated across state lines, the opportunities for conflict and the complexities of law and equity, increase exponentially. Certainly the major western intrastate, interbasin transfer project is the State Water Project in California, planned to have an ultimate firm yield of 4.3 million acre-feet per year and moving water from the north to the south through 715 miles of aqueduct serving municipal, industrial, and agricultural users en route.[4] A careful study of the history of that project—its conception, design, and probably most importantly the ongoing intrastate controversies, conflicts, and regional bitterness generated in its implementation process—should be required reading for water planners and decision makers concerned with acquiring new water supplies. The Federal Central Valley Project in California, also wholly intrastate, has been and still is subject to many of the same problems. Diversions from the Lower Colorado River to California and in the near future to Arizona through the Central Arizona Project are other examples. Major potential sources of water for interbasin diversion to arid western lands include the following.

The Columbia River Basin This potential source of new water supply in the West has been considered from a conceptual standpoint, but federal legislation, sponsored by Senator Henry Jackson of Washington, has since 1968 precluded detailed studies by federal agencies of the potential for diversion into the Colorado River System or into northern California. Legislation has been introduced in the current session of Congress to extend a similar prohibition to all interstate waters.

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The Missouri River Basin Central to much of the development of the Midwest, the Missouri remains

the object of interests in adjacent states as a potential export basin. Intrabasin states understandably object to any out-of-basin commitments of water from the Missouri in the absence of any institutional mechanism protecting long-term in-basin water needs. The Missouri River main stem is already extensively controlled under the Pick-Sloan Plan (Flood Control Act of 1944) by the six main stem dams and reservoirs—Fort Peck, Sakakawea, Oahe, Sharpe, Francis Case and Lewis and Clark—for navigation, flood control, hydropower, and in-basin irrigation, municipal, and industrial uses. Any large exportation would involve tradeoffs with these presently authorized commitments for in-basin uses. In the recently (March 1982) completed report on the Six-State High Plains Ogallala Aquifer Regional Resources Study, conducted under the auspices of the Department of Commerce Economic Development Administration, the U.S. Army Corps of Engineers (Corps) examined the potential of the Missouri as a new water source for irrigation in the six states of Nebraska, Colorado, Kansas, New Mexico, Oklahoma, and Texas.[5] The legislation authorizing the Corps study explicitly limited the source basins for analysis to areas "adjacent" to the six-state region to be served. This eliminated the Columbia River from possible consideration. The Mississippi was also ruled out, and thus the Missouri was selected by the Corps as a potential source basin for its work. Several diversion points and transfer routes were studied. Reconnaissance level design and cost estimates were made for ranges of transfer quantities. The Corps did not make a determination of the amounts of water that might be "surplus" to in-basin needs and thus available for diversion. Transfer quantities of less than two million acre-feet annually to 3.4 million acre-feet were investigated for alternative routings and sizes of facilities. Resulting cost estimates (total investment costs in 1977 dollars) ranged from $2.9 billion to $7.4 billion for a 10-year construction period, and from $4.4 billion to $11.2 billion for a 20-year period for delivery to terminal reservoirs. Unit costs (per acre-foot) of water delivered to terminal storage reservoirs under the alternative routes projected by the Corps from Missouri River sources ranged from $227 to $335. These costs are significantly in excess of the ability to pay for imported water by irrigation agriculture, in the time frame of

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the High Plains Study to year 2020. They also do not include the additional water distribution costs from terminal storage to farm headgates.

Western Arkansas Basins In addition to the potential diversions to the High Plains region from the Missouri River basin, the Corps also assessed the feasibility of interstate, interbasin transfers into the region from several streams in western Arkansas and northeastern Texas. The Arkansas, Ouachita, Red, and White rivers of western Arkansas, and the Sulfur and Sabine rivers in Texas were considered as possible sources. Water transfer quantities for the southern alternative routes ranged from 1.26 maf per year to almost 8.7 maf annual diversion. Unit costs per acrefoot of water delivered to terminal storage sites by the two alternative southern routes of importation to the High Plains region ranged from $430 to $569, considerably more costly than the projected northern routes.

The Mississippi River System The large flood flows of the Mississippi have long been studied as a potential source for water export. Key questions raised by in-basin interests are the long-term needs of in-basin users, high minimum flow requirements to repel intrusion of salt water up-river from the Gulf and for sediment transport, and the need for maintenance of fresh water inflows into coastal bays and estuaries of Louisiana. The extremely limited availability of storage for intermittent diversions of flood flows when they occur is a major roadblock to export from the Mississippi. A feasibility study by the Mississippi River Commission in 1973 of diverting water from the Lower Mississippi River Basin to West Texas and eastern New Mexico exemplifies previous studies of the Mississippi as a potential source basin.[6] The study indicates a technical feasibility for such diversions, but a high cost of delivered water, at about $330 per acre-foot. Total capital costs for the system were estimated at $19.5 billion in 1972 dollars.

Weather Modification Weather modification projects throughout the West have shown variable results to date. While some statistically significant precipitation enhancement results can be documented, they are not consistent and dependable, particularly for the

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convective (summertime) cloud systems of the Great Plains area. Wintertime and high altitude (orographic) cloud seeding programs have been relatively more effective than the summertime experiments, particularly for increasing snowpacks, but significant operational and institutional problems confront all weather modification projects. A related area of water supply augmentation is found in the treatment and management of snow accumulations in those regions or altitudes where significant snowpacks occur. Ongoing research and trials of methods and materials for improving water yields, decreasing evaporative losses, and managing the rate and timing of runoff from snow fields show promise of more dependable water supply management from this source. By the late 70s, the scientific community (cf. U.S. Interdepartmental Committee on Atmospheric Sciences or ICAS)[7] generally accepted the operational capability for seeding wintertime (orographic) clouds to increase precipitation by a factor of 10 to 20 percent. On the basis of a 15 percent increase in snowpack due to seeding, it has been projected that an additional 2+ million acre-feet of water per year, average, could be produced in the Colorado River Basin, at a (1977) cost of about $1.50 per acre-foot. In agricultural use, irrigation benefits are estimated at about $50 per acre-foot of available water. Most other uses have higher per acre-foot values than agriculture. Such large-scale precipitation enhancement would require much larger federal/state cooperative projects than have been attempted to date. A largely unresolved question is, who owns the additional water produced?

Water Harvesting—Water Banking A local water supply enhancement method that has seen extensive development and use in the Mid-East, Africa, and other parts of the world, but limited application in the U.S., is the so-called "water harvesting" technique. This consists essentially of intensive watershed and vegetative management on nearby non-cultivated lands, in order to capture or "harvest" the water for use on cultivated areas. There are extensive areas throughout the West where this technique could be applied. "Water banking" is a technique for capturing available surface water in excess of immediate needs and overwatering areas with favorable infiltration rates. Excess waters are "banked" in groundwater storage through deep percolation for later recapture.

― 118 ― Such projects would necessarily be extensive in nature and involve many landholders. Where state laws direct the acquisition of groundwater rights, many questions of law as well as equity arise with respect to ownership of the banked water supply.

Conjunctive Use The coordinated management of groundwater and usable underground storage capacity with surface water resources and surface storage as an integrated system can often increase available water supplies and reduce costs. The techniques for achieving conjunctive use vary with the specific situation involved. For example, where surface storage is limited or there is none, surface runoff that would otherwise be lost can be stored underground by artificial recharge for later extraction and use. Available surface storage can be used to regulate variable runoff to increase artificial recharge capability. Groundwater can be used to meet peak demands with resultant savings in transmission costs in some cases. Water storage underground minimizes evaporation losses. A degree of natural treatment results from passage of surface water through the soil column in transit to the water table. This is particularly important where polluted surface water or treatment and reclamation of wastewaters are involved. It is emphasized, however, that to achieve full benefits of the conjunctive use potential, the management plan must be based upon thorough considerations of hydrology, geology, and man-induced influences. A carefully planned program of groundwater extractions with respect to areal pattern, amounts, and timing is required in order to maximize the potential for use of underground storage. The possibility of interference with vested groundwater rights must be recognized and any necessary arrangements made for compensation, either in-kind or monetary. Conjunctive use has been extensively practiced in parts of Southern California in a variety of ways for many years with a high degree of success. Here, runoff is highly variable, available surface storage is very limited and costly, and groundwater basins are extensive, although the availability of land for artificial recharge operations is now limited. Artificial recharge and underground storage are used for conservation of local

― 119 ― runoff, for storage and distribution of imported water, and for treatment and storage of reclaimed water. Groundwater rights in several basins have been adjudicated. In at least one other basin, adjudication has not been necessary through acquiescence of the water users who have been more interested in assurance of an adequate water supply of good quality than in legal protection of water rights. Equitable physical solutions have been provided in all cases. The State of California and local agencies are now developing plans to conjunctively use underground storage capacity in Southern California for long-term carryover storage of surplus water from Northern California

imported by the State Water Project.

Desalting/Use of Brackish Water There are modest success stories to relate in agricultural water supply enhancement for the semiarid West. The U.S. Salinity Laboratory and brackish water use programs in Arizona, New Mexico, Texas and other western states have shown significant progress in water management, crop adaptations, soil treatments, and other agricultural techniques for the use of brackish and moderately saline waters. Most western states have sources of largely unused brackish water, both ground and surface, that could be developed for agricultural purposes. The State of New Mexico is estimated to have about 15 billion acre-feet of saline groundwaters (salinity ranges of 1,500 to 15,000 mg/L TDS). The economic and operational feasibility of using typical saline waters representative of New Mexico groundwaters has been investigated for several years. A variety of crops and cropping systems have been demonstrated to have suitable tolerance for such saline irrigation. Many of the more common field crops grown in the West—small grains, cotton, alfalfa, grain sorghums and others—demonstrate this adaptation. The processes of desalting have yet to be established as a large-scale solution to the problem of providing new agricultural water supplies. The increasing costs of the very large amounts of energy required for desalting have made this potential less and less attractive. Continued advances in geothermal or solar energy generation processes may provide in the future a way to treat the available brackish to saline waters on a large scale.

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Water Reclamation and Reuse The potential for reusing water, and the requirements for reclaiming it, restoring it to a quality suitable for reuse, and redistributing it among users, is a cycle of legal, engineering, esthetic, and environmental complexity. Yet, since water is not destroyed by use, it is a cycle nature has always provided. The problems are twofold: separation of use and reuse over time and geography, and the persistent pollutants which our civilization manages to insert into the cycle. The technology for treating wastewater to the point of making it suitable for reuse for irrigation is available, although public health questions about direct reuse for human consumption remain. Certainly the reallocation of reclaimed water to industrial and agricultural users is well within existing technology.

However, irrigated areas where significant volumes of reclaimed water could be used are generally at considerable distances, often with ranges of intervening hills or mountains, from the urban areas where large amounts of wastewater are generated, thus adding significantly to the cost. An example is irrigation in the San Joaquin Valley of California, many miles from the metropolitan areas of the San Francisco Bay region and Southern California. In irrigated agriculture, the increased efficiencies of present practices generally result in full use of applied water, with tailwater recovery and reuse a common practice. Opportunities for improved reuse of agricultural waters still exist on a limited basis, but do not represent significant potentials. Continued research into reuse, and its systematic inclusion in the water resource allocation planning process, are necessary steps in achieving the full potential of this measure.

Improving Existing Project Operations Many projects, in fact most existing projects for surface water development, were planned and authorized under planning concepts, standards and criteria, economic conditions, projected downstream needs, projected upstream depletions, operational criteria, contractual requirements, and political attitudes that differed significantly from those prevailing today. This is true of the main stem developments on the Missouri River, the Federal

― 121 ― Central Valley Project in California, and the California State Water Project, to mention but three examples. At the times these projects were originally planned and authorized, little if any thought was given to the potential for increased yield through conjunctive use with groundwater resources, to the potential benefits which could result from integrated operation with other projects on a "systems" basis, to requiring efficient use of water by water service contractors, or to operating the projects on benefit/risk basis, among other potentials for increasing yields. As stated above, the Missouri River was studied by the U.S. Army Corps of Engineers as a potential source of water for exportation for irrigation in the High Plains area of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, and Texas, under the recently completed federally funded High Plains-Ogallala Aquifer Regional Resources Study. The Missouri is now controlled by six main stem dams and reservoirs—Fort Peck, completed in 1935, and the other five authorized under the Pick-Sloan Plan by the Flood Control Act of 1944. By the authorizing legislation, these projects are committed to navigation, flood control, hydropower, and irrigation, municipal, and industrial uses in the

basin states. The Corps studies indicated that, under the present authorizations and commitments, little if any surplus water would be available for exportation without encroachment on navigation, hydropower generation, and future inbasin uses. However, more recent projections of in-basin uses and depletions are significantly lower, and questions have been raised as to the justification under present conditions for the present allocation of storage and water for the limited navigational use of the Missouri River to Sioux City. More water might be available for both in-basin use and exportation were the allocation and the operational criteria to be changed to accord with today's projected conditions and needs. Were the Federal Central Valley Project and the California State Water Project, both of which divert from the Sacramento River and tributaries and from the Sacramento-San Joaquin Delta, to be operated as an integrated system with proper regard for hydrologic diversity, there could be a potential increase in yield of 500,000 to 1,000,000 acre-feet per year. Hydroenergy production might also be increased. Conjunctive use with groundwater resources would provide additional benefits. Any proposal to improve the efficiency of operation of existing projects would require Congressional and state approval. No

― 122 ― doubt there would be strong opposition from some present project beneficiaries. The potential for increased water supply and other benefits seems to warrant the attempt.

Better Allocation of Resources The discussion above of improved management and operation of existing projects implies reallocations of current supplies and allocation of augmented supplies in accordance with today's needs and conditions. There are also situations where undeveloped resources could be allocated and developed to sustain current uses. Only one example will be discussed here, that of the undeveloped groundwater resources of the High Plains-Ogallala Aquifer region of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, and Texas. In 1980, of the total of 140.8 million acres in the High Plains area, over 15 million acres were irrigated with groundwater extracted from the Ogallala and associated aquifers. It is projected that 5.4 million acres will revert to dryland farming or be abandoned by 2020 because of physical or economic exhaustion of the underlying groundwater resources if no new remedial

actions are taken. The rate of reversion will accelerate thereafter. Of the more than 125 million acres of nonirrigated land in the region, another 17 million acres were in dry cropland. Of the total area, almost 30 million acres are classified as marginal for irrigation, but are suitable for some types of dryland production such as grazing. These nonirrigated areas are underlain with groundwater resources in amounts that vary with location. It is suggested that the groundwater resources underlying the marginal lands, and some of the other lands not especially well suited for irrigation, might be developed and conveyed over time to the presently irrigated lands and the nonirrigated prime lands that may go under irrigation. Of course, it would be necessary to obtain, by direct purchase or by condemnation, the water rights or surface development rights of those lands and owners from which the underlying waters would be purchased. Some changes in state laws would be necessary. There would be some legal/institutional difficulties to be overcome. This concept would have several advantages: · The lands from which the water would be taken could remain in their present uses or other dryland uses.

― 123 ― · There would be a number of relatively small projects which could be implemented at the appropriate times with respect to the declining availability of underlying water for the recipient lands, as contrasted to one or two very large importation projects. Implementation could be accomplished in stages. · The investments required at any one time would be relatively small. · Implementation could be accomplished by local public agencies rather than the master regional agency required for a large importation project. · The elevation differences are relatively small and pumping costs would be much less than for importation. · Surface storage reservoirs would not be required, thus minimizing evaporation losses.

· Total costs should be significantly lower. · At least some of the owners no doubt would welcome the money derived from sale of their groundwater rights, which they might not ever exercise on their own behalf.

Groundwater Management/Recharge Artificial recharge is frequently touted as a principal technique to be applied for alleviation of the present water supply deficiencies in the West. Artificial recharge is already being widely applied throughout the West. However, application of this technique to new situations will depend on the availability of water for increased recharge that would otherwise be lost for beneficial use. There is now little surface water wasted in the West on a regional or river basin basis; most surface water is already being used for one or more beneficial purposes. The feasibility of artificial recharge also depends on the availability of sufficient usable underground storage and transmission

― 124 ― capacities. Effective artificial recharge requires land and physical facilities. The investment and operation and maintenance costs may be substantial. In some states, there are legal questions as to the ownership of and control over the recharged water, i.e., the right to recapture. There are opportunities for further augmentation of usable supplies in the West through artificial recharge, but they are not widespread. Artificial recharge will be particularly valuable for the underground storage of imported and reclaimed waters.

Other Possibilities and Research Needs One very new technology may have potential application in areas throughout the West that have already seriously depleted available groundwaters. Methods are undergoing testing in the south area of the Texas High Plains for the secondary recovery of additional groundwater supplies from the unsaturated zones of an aquifer. The concept is that in many aquifers, as much or more water remains in the formations after depletion by usual extraction methods, due to molecular or capillary attraction, as was removed by normal gravitational (pumping) forces. This could represent a very significant supplemental water supply if this ongoing research demonstrates both a technical and cost-effective capability. A variety of techniques for reducing nonproductive losses of water by

evaporation, transpiration, and/or by losses to runoff or deep percolation to nonrecoverable areas such as saline sinks or aquifers are being investigated. Methods to improve infiltration and deep percolation on-site, and to reduce losses to nonproductive deep rooted vegetation like phreatophytes and noxious brush species, hold out strong prospects for local water enhancement in the West, but more research is needed.

Conclusions Certainly there are no "quick fixes" for new water supplies for the semiarid West. Nor, to continue in the vernacular, are there any "free lunches". With complete rational planning and management, and no objections from the source areas, interbasin diversions of water could be achieved to the probable benefit of all concerned. The reality is that even on a small scale, the

― 125 ― probabilities are not great. Fear of exploitation on the part of export areas, and an appearance of greedy provincialism in some areas seeking imports, combine to create almost impenetrable barriers to the successful implementation of any diversion scheme. Lack of available funding now precludes large-scale structural solutions to problems of water supplies for irrigation. Other processes show promise, but the potential for a significant breakthrough in local water supply or large-scale water supply augmentation for the West in the foreseeable future is limited. A state-of-the-art evaluation of a large set of emerging technologies for enhancing local water supplies, while not consistently discouraging or pessimistic, nevertheless offers small relief for the major irrigated agricultural production areas of the West, which are presently dependent on seriously overdrafted groundwater sources or very limited surface water supplies. Significant projects are still underway for agricultural water supply enhancement. Examples are the extensive weather modification and precipitation management research programs; the adaptation and use of brackish and saline waters for certain crops; and the secondary recovery of additional waters from aquifers where gravitational waters have already been depleted due to overdraft. These and other methods may provide some temporary and partial water supply sources for western agriculture, but none provide long-term solutions to the water crisis. These are nonetheless the only solutions, limited as they are, that appear to be implementable for many years.

Discussion: Herman Bouwer New water supplies or water importation schemes usually mean transferring water from places where the supply exceeds the demand to places where the demand exceeds the supply, or from places where the economic returns from the water use are low to where they are high, all in accordance with the second fundamental law in hydraulics: water runs uphill—to money! This does not bode well for agriculture, which traditionally is accustomed to inexpensive water for irrigation. Rather than for irrigated agriculture to acquire additional water supplies, current trends seem to be more in the opposite direction, i.e., sales of irrigation water rights for municipal and industrial uses. The authors have done an excellent job in summarizing the various large water-transfer schemes that have been proposed over the years, and other possibilities for augmenting local water supplies. One source not mentioned is icebergs that would be towed from the Antarctic. Is this no longer a viable concept? Accurate cost figures for large water transfer schemes are difficult to obtain. Preliminary estimates all indicate, however, that costs are high: capital costs of several thousand dollars per acre-foot per year capacity, and total costs of several hundred dollars per acre-foot at the aqueduct or reservoir. To this must be added the cost of further distribution of the water to the points of use. For a simple project like the Central Arizona Project where water will be pumped from the Colorado River and transported a few hundred miles into south central Arizona, construction costs are already about 2.4 billion dollars for a capacity of 1.2 million acre-feet per year (or about $2,000 per acre-foot per year), and this does not include the cost of getting the water from the main aqueducts and reservoirs to the points of use. The cost of the water to consumers is projected at $52 per acre-foot for agricultural users and $82.50 for municipal and industrial users, again at the main aqueduct. These figures will soon be revised, probably upward. The cost of water in southern California from the California Aqueduct is about $100 per acre-foot. This figure could double in 1983, as new contracts for electric

― 127 ― power will be negotiated. New projects can be expected to be a lot more expensive. Man-made obstacles (legal, social, environmental, etc.) to large transfer projects seem more difficult to overcome than the technical problems, which can be solved by good engineering. It should be possible, however, to develop long-range projections of water needs for selected basins, to identify basins of water surplus and water deficit, to design water transfer projects, and, if economically and environmentally attractive, to build them. The

Sporhase decision (Sporhase v. Nebraska, U.S. Supreme Court, 2 July 1982), which declared groundwater an article of interstate commerce subject to congressional regulation, may help overcome political opposition from water surplus states against export of water to deficient areas. Long-term economic and social values for the life of the project should be considered rather than payout period economic aspects which, because of present cost levels for water, are almost always unfavorable. To translate from the Dutch, "A nation that lives builds for its future"! If we leave out the element of moving water over great distances, development of new water supplies simply means transferring water from a use with a low economic return to one with a higher economic return. This, of course, includes water conservation, where losses and wastes of water are reduced and put to more beneficial use. In view of the costs and the many difficulties of water transfer schemes, water conservation is increasingly considered as the best and most immediate solution to problems of water shortage. The authors allude to water conservation and increased irrigation efficiency, as do other chapters in this volume. However, further discussion of some opportunities for water conservation seems warranted. One such opportunity is to reduce water use by agriculturally nonbeneficial vegetation such as phreatophytes in floodplains. Phreatophytes have been estimated to cover about 15 million acres in the western states and to consume about 25 million acre-feet of water per year. This is the equivalent of 20 Central Arizona Projects! Complete eradication of the phreatophytes, as advocated a few decades ago, is not compatible with wildlife and scenic considerations. Thus, selective removal will be more acceptable. Proper control can be achieved by keeping the phreatophytes away from the water (by selective cutting and floodplain management), or by keeping the water away from the phreatophytes (by lowering groundwater levels or reducing seepage from stream channels). Care should be taken that

― 128 ― replacement vegetation does not use appreciable amounts of water. With the high cost of imported water, saving water by phreatophyte control may become attractive. Runoff farming offers great potential for the millions of acres of marginal lands with insufficient rainfall or irrigation water for normal crop production. Crops can then be grown in widely-spaced rows at the base of contour strips that have been treated chemically or mechanically to increase runoff from rainfall, thus concentrating the rain on the crops. The systems can be designed to yield more runoff than can be used by the crops for evapotranspiration, thus increasing deep percolation from the crop rows and producing more groundwater recharge. Runoff farming and replenishment irrigation have great potential for the management of abandoned irrigated

land, which otherwise could develop problems of dust and tumbleweeds. The crops should be deep-rooted or drought-tolerant to survive long periods of no rain. Supplemental irrigation may be desirable. Reuse of wastewater, particularly municipal wastewater, requires considerable advanced planning to ensure that the treatment plants and the irrigated fields are not too far apart, and that land treatment or groundwater recharge opportunities can be utilized. If partially treated wastewater can be put underground with infiltration basins and pumped from wells after it has moved through the vadose zone and aquifer to become "renovated water", the cost of treating the wastewater to meet the public health, agronomic, and aesthetic requirements for unrestricted irrigation can be greatly reduced. There are also increasing trends toward local or on-site reuse of municipal wastewater for landscape irrigation, golf courses, cemeteries, etc. Last but not least, there is irrigation efficiency, which often is the center of attention because irrigation uses so much water (almost 90 percent of all water in Arizona, 85 percent in California) and field irrigation efficiencies are low. Many people have the misconception that a field irrigation efficiency of 60 percent means that only 60 percent of the irrigation water is effectively used, and 40 percent is wasted. Of course this is not true. The forty percent of the water not used by the crop in this case is in the form of runoff at the lower end of the field and/or of deep percolation from the root zone. Both types of water can be recovered and reused again. For this reason, the irrigation efficiency of entire irrigation districts or irrigated valleys is much higher than the efficiencies of individual fields. As the saying goes, "the upper basin's inefficiency is the lower basin's water resource."

― 129 ― The real loss of water is the consumptive use or evapotranspiration, and that does not change much with irrigation efficiency. However, if the irrigation efficiency is increased, for example from 65 to 85 percent, less energy is needed for pumping, and higher yields are generally obtained, because of better water management and reduced leaching of fertilizer. This is really the main purpose of increasing irrigation efficiency: to increase crop yield per unit of water consumptively used. It is, of course, also possible to reduce evapotranspiration by not growing crops in the hottest part of the year (late season cotton, winter vegetables instead of summer crops, etc.) and increase water use efficiency that way. However, the main prospects for water saving in irrigation lie in increasing crop yields. Average crop yields typically are only about 20 percent of record values, so there is still room for improvement in crop management. Also, research should be greatly stepped up to create new, high-yielding varieties, using new developments in genetic engineering. New approaches such as the use of growth hormones and biostimulators should be investigated with

vigor. If we can double the yield per acre, the same crop can be produced with half the land, essentially half the water, and essentially half the salt load on the underlying groundwater due to deep percolation. Thus, growing the proverbial two blades of grass where only one would grow before is still the name of the game.

Discussion: Marion Marts The chapter by Banks, Williams, and Harris is a realistic and comprehensive assessment of the prospects for developing large-scale new agricultural water supplies in the semiarid West. The authors conclude that the prospects are poor in the foreseeable future. This discussant shares this conclusion, and indeed with respect to large-scale importation would argue that the prospects approach zero. Let me elaborate on this latter point a bit, and then proceed to speculation on some broader issues. Large interregional transfer of water is an idea that won't go away, but whose time refuses to come. As the authors point out, the inhibiting factors have always been strong; my thesis is that they are growing stronger over time, so that whatever prospects once existed are fading. The Columbia River illustrates the point nicely.

― 130 ― Then Assistant Secretary of the Interior William Warne's famous "climb the ladder of rivers to the north" speech stimulated the first major review of large-scale interstate water transfer: the Bureau of Reclamation's United Western Investigation, which in 1950 and 1951 reported on a reconnaissance of a variety of possibilities for transferring "surplus" Pacific Northwest water to the Southwest, but concluded that tapping anything north of the Klamath River was economically infeasible. It is interesting that even in that heyday of water project development, economic feasibility was a constraining criterion. Also interesting was the fact that certain northwest waters—the Rogue River and Flathead, Pend Oreille, and Coeur d'Alene Lakes—were declared sacred and off-limits. The investigation was quickly and quietly terminated when Northwest congressmen discovered what was going on. A blizzard of proposals followed the 1963 Arizona v. California decision. Anyone with a roadmap and pencil could play the game. By 1969, Bingham inventoried 14 interregional and 10 international proposals, and there were many variants of these. Banks and colleagues describe four of the major proposals as illustrations. Senator Jackson of Washington saw fit to take the Columbia out of the game by imposing a congressional moratorium, which effectively stopped federal agencies from planning to rearrange the

Columbia. While high cost can be cured by massive subsidy, and political clout can erode over time, a new and very fundamental element has been added. This element is, surprisingly, shortage. Competition within the Columbia River Basin for water for hydropower, for anadromous fish, and for additional irrigation has become fierce—reinforced by two drought years in the 1970s. The Northwest Regional Power Council, for example, has accepted a calculation that provision of adequate spring flows for the juvenile salmon migrating to sea will cost in the order of 500 to 550 megawatts of firm power. In the same vein, irrigation expansion will impose annual power costs on the region amounting to more than $100 per acre irrigated—in some cases more than $200—from a combination of lost generation and consumption of electricity for pumping. Hydropower operation is now a claimant for water that once was surplus during the high flow season (late spring and early summer) as a result of upstream storage, the ability to sell electricity to the Southwest via the Intertie, and the gradual transition to peaking mode for the hydropower plants. Indian claims to water and fish are far from quieted, and will complicate the planning picture for years.

― 131 ― All of these factors mean that there are substantial opportunity costs of diverting Columbia River water which must be included in any responsible benefit-cost analysis. The days when outflow to the seas could be considered surplus are gone. By extension, the principle of opportunity cost applies to all available rivers, although the details and values will vary. This is a powerful inhibition on any river pooling scheme. The authors illustrate this principle in the case of the Missouri River by pointing to the trade-off between navigation and out-of-basin diversion. Banks and his colleagues proceed from the impracticality of large water transfers to an excellent review of the possibilities of improving the efficiency with which available water supplies are used, and point out institutional factors—water laws, property rights, custom, etc.—which inhibit increased efficiency. I applaud this discussion and can only add, let's get on with it. But all of this suggests some interesting speculation. If my thesis that large water transfers have been priced out of the market is correct, does this mean that federal intervention and federal subsidy have lost their efficacy? What potential irrigation projects remain if we can't afford to augment? Does southern Idaho claim more Snake River water for irrigation regardless of the downstream costs in lost hydropower and fish? And into what maze does enhanced efficiency lead us? Will Wyoming surrender its rights to irrigate pastures in high mountain valleys to expand the intensive agriculture of the Imperial Valley? The social cost of interregional efficiency, like the cost of augmentation, may be excessive. The sobering fact is that state boundaries

and state water codes constrain both efficiency and interstate transfer. If big augmentation and big efficiency are beyond us, what then? Perhaps the time has come to accept the proposition that there is an inevitable equilibrium between availability and use of western water resources. There will no doubt be some modest additions here and there using locally available supplies, and some abandonment here and there as water tables drop or salinity rises, but these are just perturbations on the way to equilibrium. We may have seen the last of the large new irrigation projects in the West. The next ones may be in the Mississippi Valley, as we proceed to emulate the Italian experience in the Po river basin.

― 132 ― A final comment about long distance transfer. We are habituated to think of interstate and international water transfers only in terms of large scale, and chiefly for irrigation. This creates the twin problems of large cost and low repayment capacity, compounded by the perception of unfair interregional competition. If we have long distance transfers in the foreseeable future, they will more likely be of modest volumes for specific and high-value uses, such as coal gasification or transport, or municipal use, analogous to oil and gas pipelines and perhaps even sharing the latters' rights-of-way. Such systems would have much greater social and economic acceptability than would canals built to move the equivalent of the Colorado River, and might help retard the transfer of irrigation water to industrial and urban areas in water-short areas. Macro-think has brought no large interstate water transfers in the three decades since the United Western Investigation, and may actually have impeded the search for more efficient allocation and use of available water. It may be time to try micro-think.

― 133 ―

Chapter 5— Increasing Efficiency of Nonagricultural Water Use by J. Ernest Flack

Abstract Increased efficiency in use of nonagricultural water can have a small but significantly important impact on water availability for irrigated agriculture in the West. Water withdrawal to meet commercial, industrial, and residential water demands is less than 5 percent of the withdrawal for agriculture, but meeting these demands ties up some of the most valued storage sites and earliest priority water rights. Conservation programs, if carefully designed, properly implemented, and fostered over the long term, can alleviate some of the adverse consequences that growing municipal and industrial water demands have on irrigation. Compared with flat-rate, nonmetered water usage, savings of as much as one-third can be realized. Conservation can, however, have adverse effects on return flows to receiving streams and groundwater aquifers.

The arid and semiarid West is the scene of important economic growth and opportunity, much of which is dependent on water resources development. While there are some disadvantages associated with this land of sharp contrasts, its attributes are attracting people and industry at rates well above the nation as a whole. A number of trends seriously impact the water resources of the area and its irrigation-based agricultural economy. These include rapidly increasing population concentrated in urban centers, industrialization, heavy recreational use of the natural environment, and energy resource development. The role of water is pivotal because there is not much undeveloped, unappropriated water remaining. Although all the water allocated or available to the various states is not now being used, virtually all of it is "spoken for" through various reservations, by conditional water rights, or preliminary permits to acquire appropriations. The result is sharp competition for water, especially in places and times of scarcity.

― 134 ― Users can follow three possible strategies in meeting their projected demands for water withdrawals. These are to (a) develop new water supplies, (b) reduce the demand, and (c) transfer water from lower economic uses. In this paper, we focus on reducing the demand for water by

nonagricultural water users. Since the municipal-industrial sector has the highest value-in-use of water, conservation is important because it affects transfers from lower economic uses, particularly irrigated agriculture. Agriculture uses by far the largest percentage of western water—90 to 95 percent in terms of both withdrawal and consumptive use. It must be emphasized, however, that just because one economic sector has a higher value-in-use than another, it will not necessarily "buy out" the entire lower valued use. For example, assume water is being transferred from a lower to a higher value-in-use. As the demand is met in the higher valued use, the marginal value per unit of water will fall until the incremental value-in-use of the two uses are the same and transfers cease. In plain language this means that municipal and industrial water users can, generally, purchase sufficient water from agriculture to meet their demands, but still leave large quantities in agriculture. A related but crucial issue is that the water rights acquired from agriculture, in order to be most useful to municipal and industrial interests, are the most senior rights that exhibit the greatest hydrologic and legal certainty.

Changes in Urban Runoff The development and control of urban runoff can, to a degree, both reduce the demand for urban water and add to the supply. Stored runoff can be utilized to meet landscaping irrigation requirements of both public and private property. For instance, impervious areas such as tennis courts, streets, and parking lots can be constructed so that the runoff is stored for use in forming blueways and maintaining greenways. At the least, this source can be used to water public parks, commons, golf courses, planted medians, etc. Judicious use of stormwater could possibly supply one-fourth to one-half of the public water demands of a city in the West.

― 135 ―

Reuse of Municipal Wastewater Water utilities have always sought to alleviate supply problems by developing new sources. Traditionally, water has been supplied to municipal residents, used, treated, and then discharged as wastewater effluent. The reuse of wastewater can reduce the demand for new water supplies.

Recycling Recycling of water has been practiced since the beginnings of civilization. The unplanned successive use of the wastewater of one settlement by downstream communities has increased with rising populations. The U.S. Environmental Protection Agency has estimated that during low flow periods the proportion of wastewater in some surface water supplies may exceed eighteen percent, with an average of about three and one-half percent.[1] The planned reuse of water for some uses, generally nonpotable, has been recognized by many as a viable alternative to new water supplies.[2] The advantages are obvious: water withdrawals and wastewater discharge are reduced in magnitude. A new level of interest in water recycling has been generated as the result of research in advanced wastewater treatment. The costs of advanced treatment have been reduced and approach more closely the costs for raw water supply treatment.[3] Recycling systems can be divided into two general categories, indirect reuse and direct reuse. Indirect reuse involves the discharge of a wastewater into a surface or groundwater supply and then subsequent reuse of the water in a diluted form. Wastewater can be used directly in irrigation, by industry, and for some nonpotable residential applications. A 1975 survey indicated that 358 municipalities, located primarily in the Southwest, reuse wastewater for such purposes.[4] Groundwater recharge using sewage effluent is presently practiced in many locations in the United States. The primary reuse is for irrigation with a small percentage being allocated for recreation, fire protection, and other municipal purposes. Endorsement of wastewater reuse has not been universal. Some authorities view it as a major solution to water supply problems, while others have voiced considerable concern.[5] The American Water Works Association and the Water Pollution Control Federation have issued a joint resolution recognizing the potential of wastewater recycling, but cautioning that further research is needed on the possible health hazards involved. Surveys of health officials have expressed similar concerns. The possible long-term effects of ingestion of low levels of viruses,

― 136 ― organics and heavy metals that may be present in treated wastewater have not been determined. Questions relate to the frequency and the amount of recycled water ingested. Before recycled water can be used as a drinking water supply, most authorities agree that there is much more to be learned.[6]

The acceptance of recycled water is of considerable importance in planning for wastewater reuse. Pagorski found that 81 percent of a sample survey population were willing to use recycled water if it was guaranteed to be safe.[7] Bruvold and Ongerth found that the degree of acceptance decreases with higher body contact.[8] A survey in the Denver area showed that half the sample population would accept purified wastewater for drinking.[9] On the other hand, Gallup reported that 54 percent of those surveyed opposed drinking recycled sewage.[10] Studies by Sims and Baumann[11] and by Greenberg[12] correlated higher reuse acceptance with higher levels of education. It appears that public attitudes currently oppose using recycled water for drinking, cooking, bathing, laundry, and swimming, but do not oppose its use for waste disposal and irrigation purposes. Methods of direct recycling range from those instituted on an individual basis to system-wide operations. The most cost-effective means of recycling water is to reduce or minimize the treatment required. To better understand how recycling of water in the home can be accomplished and what type of treatment is needed, several authors have looked at the quality of each use effluent.[13], [14] A number of recommendations have resulted from these findings;[15] see Table 5.1.

Individual Home Recycling The waste stream from the various domestic water uses can be categorized as grey water or black water. Those flows containing high concentrations of organic matter are termed "black water", while flows polluted primarily with soap and detergent wastes are termed "grey water". Currently these two wastewaters are combined and discharged into the sewer system. McLaughlin found that a system separating the two wastewater streams and reusing the grey water for toilet flushing saved approximately 23 percent of normal water usage.[16] In 1969 Bailey and others made cost estimates on a number of types of individual home treatment systems for in-home water recycling.[17] Their general findings indicated that treatment costs were too high to make recycling cost-effective. A follow-up study by Cohen and Wallman indicated that average savings of between 23 and 26 percent of total water use could be obtained

― 137 ―

Table 5.1 Potential for Residential Water Reuse

― 138 ― by grey water recycling for toilet flushing.[18] Widespread reuse of black water flows within households is extremely unlikely because of possible health hazards, although closed systems for households have been developed.

System Recycling The literature contains much discussion on system-wide reuse possibilities. The classic case of direct reuse of wastewater took place in Chanute, Kansas, when a severe drought brought about a water shortage and the recycling of wastewater was necessary to supply the town's water needs.

Windhoek, Namibia, has recycled part of its total supply for domestic uses since 1968. The use of dual systems to recycle water has been examined by a number of authors. Haney and Hamann based their calculations for a dual system on a need of 40 gallons per capita per day (gpcd) of high quality water.[19] Potable water would be furnished for drinking, cooking, dishwashing, bathing, and cleaning purposes. Nonpotable water would be furnished via a recycling system for toilet flushing, lawn irrigation, evaporative cooling, and clothes washer uses. Deb and Ives estimated that 85 percent of the total supply could be provided by the nonpotable system.[20] DeLapp found that by using reclaimed water for lawn irrigation, toilet flushing, and fire protection, the quantity of potable water supplied could be decreased by 73 percent.[21] Dual systems in Coalinga, California, and Catalina Island, California, are two examples of operating recycling systems, but widespread use is considered unlikely at present costs and availability of raw water.

Reuse of Industrial Water Conservation by industry, even more than urban use, depends on cooperative efforts by the industry, because the cost of the water compared with other inputs in production is usually so low that economic incentives cannot be counted on to effect reductions in demand, although there now exist incentives to reduce waste treatment costs. Reflecting this same relationship is the small price elasticity for low water-using industries, estimated at 0.1 to 0.2, or a 10 to 20 percent reduction in demand for a doubling of price. Demand reduction by commercial users such as restaurants, stores, and offices, is also difficult to effect except through pricing and utility encouragement. While very few studies of commercial price elasticity have been published, it appears that it is in the neighborhood of 0.2.

― 139 ― Once an industry or commercial enterprise has decided to implement water conserving practices, the results can be quite remarkable. Water can be reused within the plant, recycled within various processes, or use can be reduced by changing the operation or process. Closed systems may eliminate any discharge whatsoever. It should be recognized that while many of these conservation techniques can be included in plant modernization or remodeling, they do cost money. For instance, water demand could be reduced from 5 bbl to 2 or 3 bbl of water for every barrel of oil produced from oil shale, but at not insignificant additional cost.

Reductions in withdrawals from surface or groundwater sources obviously leaves more of the resource for other users. Reuse of industrial water will often reduce the quantity of effluent discharge. As with municipal return flows, these may be a major source of supply for downstream appropriators. Thus, the effect of conservation in industrial water use on downstream water users can be substantial unless there is a parallel reduction in withdrawals from the same water source.

Use of Return Flows Return flows are important in supplying downstream appropriators. Returns, especially from imported or developed water, can be effective in reducing the need for development of new supply sources, because western water law usually allows the developer of new water or the importer to retain ownership of the water as long as it can be identified. This is not true of salvaged water, that is, water native to a watershed that has been saved by some conservation means. Here the increased supply is usually considered to be added to the regular water supply of the receiving stream or groundwater source. Thus, return flows can be an efficient source of water for greenbelts and other environmental or recreational uses when not a part of the regular supply. The effects of urban water conservation on downstream receiving streams can be significant during low-flow periods. The effects are of two kinds. One is the reduction in sewage effluent entering the receiving stream. In many locations downstream, direct flow and storage appropriations are dependent on effluent return flows, or a municipal utility may be counting on its effluent to meet the rights of senior downstream appropriators when the utility diverts water upstream under a junior appropriation. In either case, any reduction in the effluent discharge can

― 140 ― adversely affect the downstream water users—in the first case by reducing the amount available to downstream junior appropriators and, in the second case, by either requiring reduced diversions upstream by the utility or the release of storage water to meet senior rights. The second effect of an urban conservation program is the reduction in lawn watering. Since an effective conservation program can reduce watering to a level at or below the consumptive use requirement for a good lawn, the deep percolation and runoff components of applied water are virtually eliminated. These excess waters either recharge the groundwater or enter the storm sewers and other channels leading to a receiving stream. If the groundwater is hydraulically connected with the receiving stream, the effect on the stream is the same as that of a reduced discharge to the stream.

Modifying the Demand for Urban Water Urban water conservation received national recognition in the report of the National Water Commission.[22] The Commission recommended metering, changes in building and plumbing codes, reduced leakage, and pricing as alternatives to increasing supply. The Clean Water Act and similar water pollution legislation have encouraged conservation as a means of reducing sewage flows, thus making possible reduced wastewater conveyance and treatment costs. The Executive Branch has initiated a series of steps and programs aimed at fostering water conservation at federal installations and in federal projects. Methods and means of urban water conservation can be categorized as follows:[23] structural methods, operational methods, economic means, and socio-political procedures. These alternatives are, in turn, subject to acceptance and implementation by three groups: the water policy decision makers, the water utility managers, and the water customers.

Structural Methods Included in this category are water-saving plumbing devices and fixtures. These include low-water-using showerheads, clothes and dishwashers, toilets, faucets, and similar appliances and fixtures. Meters can also be included because of the psychological effect they have, apart from the effect of price. Structural methods include various kinds of dual systems ranging from

― 141 ― single installations that recycle grey water to communitywide systems for potable and nonpotable water. Flow reducers which directly limit the flow rate can be included.

Operational Methods This category includes such things as reducing system pressure in anticipation of peak demands so that delivery rates are reduced. Detection, location, and repair of leaks is an important operational procedure, as is full accounting and control of public uses. The possibility of restricting deliveries to certain classes of customers in times of peak demand can result in conservation. The system over-design of utility water lines to meet fire requirements may impact conservation practices because the over-capacity allows increased peak demands.

Economic Means Rate structures which approach marginal cost pricing have direct conservation implications. Seasonal, peak, or demand pricing, including time-of-day pricing, can be justified by the resulting lowered demand. Development charges, or tap fees, can effect water use through growth limitation and through smaller meter size installations which limit delivery rates. Pricing and incentives can be used to encourage installation of watersaving devices and adoption of other conservation practices.

Socio-Political Procedures Included are rationing and restrictions, limiting water usages to certain times and for certain uses, as well as zoning and building codes which require conservation practices such as installation of water-saving plumbing fixtures. Horticultural changes can have important effects on water use by reducing sprinkling requirements, especially in arid and semiarid regions. Public education to increase acceptability of urban water conservation is extremely effective if it can be done with specific goals in mind.

Feasibility The adoption of conservation alternatives must meet four tests of feasibility: · Engineering and technological feasibility is perhaps the simplest to determine. A feasibility study answers the question of whether the alternative is physically possible, e.g., is the device available? · The second test is economic and asks the question, do the benefits exceed the costs?

― 142 ― · The environmental test is more difficult since it requires an evaluation of the environmental consequences, both positive and negative, which may result from adopting a particular alternative. · The fourth test is the most subtle and deals with changes in lifestyle or social well-being which may result from implementation of various urban water conservation alternatives.

Water Conservation Programs Combinations of the various water conservation alternatives described above can be designed to fit specific situations. All of the previously discussed conservation methods affect one another, and are not strictly additive; therefore, absolute savings cannot be predicted by adding up the savings of the methods adopted, but judgment must be used to estimate the total effect of a combined program. This is illustrated below.

Baseline Conditions To evaluate a program of water conservation, a baseline must be established against which savings can be measured. For illustrative purposes, a typical but hypothetical household is assumed; see Table 5.2. The household has three members, two bathrooms, a dishwasher and a clothes washer, and the lawn size is assumed to be 6000 square feet. The home is not metered and the rate of sprinkling application is 34 inches of water per year, well above the irrigation requirement of 23 inches needed to meet the potential evapotranspiration less effective rainfall for a semiarid location. In-house uses for baseline conditions are assumed as 64 gallons per capita per day (gpcd). Average daily water use for the three-member household is 192 gallons per day per dwelling unit (gpd/du) domestic use plus 348 gpd/du sprinkling use, or a total of 540 gpd/du. The ratio of maximum day to average day during the peak summer lawn water period is 2.1, and the peak hour to average day ratio is 5.3. The maximum day demand is 1134 gpd/du, and peak hour use is 2864 gpd/du. Sanitary sewer flows are equal to the domestic usage of 192 gpd/du. Return flow from excess lawn irrigation would be 113 gpd/du, or 56 percent of demand.

― 143 ―

Table 5.2 Residential Water Demand Daily Demand or Flow

Sector

Unmetered

Metered

Per Capita (gallons)

Per Per Capita Household (gallons) (gallons)

Per Household (gallons)

Average annual In-house

64

192

64

192

Sprinkling

116

348

78

235

Total

180

540

142

427

Maximum day

378

1134

340

897

Maximum hour

955

2864

859

2263

Sanitary sewer

64

192

64

192

Irrigation

38

113

3

10

Total

102

305

67

202

Return flow

Metering Having established baseline conditions on a flat-rate basis, the effects of metering can now be enumerated. While it seems reasonable that metering would reduce domestic usage somewhat (especially in older residences) because of leakage repair and better maintenance of plumbing fixtures, the in-house usage values are relatively conservative and for this reason no reduction is assumed. Lawn sprinkling would, however, be affected and it is estimated that irrigation usage would drop to be just equal to the irrigation requirement of 23 inches per year. The consequence of this would be to reduce the return flow from lawn irrigation to zero if the water is entirely consumptively used. Total efficiency in lawn watering is not likely, however, and some return flow from wastage is assumed equivalent to 10 gpd/du, which is about 4 percent of the applied rate.

The results of metering are also shown in Table 5.2. Total demand is reduced by 21 percent, sprinkling by 32 percent and return flow by 34 percent. Metering has been shown to be cost-effective in terms of water saved if costs of installation are not high.

― 144 ―

Water-Saving Household Devices Water-saving household devices cover a wide range of plumbing fixtures and household appliances. For retrofitting, the following items are sufficiently cost-effective, easy to install and maintain, and not disruptive to existing water use habits: · plastic bottles or dams in the toilet water closet to reduce water usage per flush. · low-water-using shower heads. · faucet aerators. Plastic bottles or dams are estimated to save from 4,000 to 6,000 gallons per year per household; shower heads save about 12,000 gallons per year per household; and aerators save about 3,000 gallons. The total savings are estimated at 20,000 gallons per year per household. All of these devices are cost-effective even at very low water prices.[15] Similar savings would be realized in new construction by installation of low-water-using toilets, faucet aerators, and shower heads. To have an impact on demand, it is necessary that these devices be installed in a large percentage of households. This is not difficult to do in new housing, where plumbing and building codes can require the devices. For retrofitting, however, a concerned public education program and ready availability of the devices are necessary. Recent research has shown that about 50 percent of the households questioned indicated they would install water-saving devices if these were made available at little or no cost. If 50 percent of a 10,000-household community installed such devices, the savings could equal 100 million gallons per year, or about 9 gpcd. This would be enough water to serve about 600 new customers. Residential water demand for households with combined metered service and household devices is shown in Table 5.3. The combined result of metering and watersaving devices is to reduce total demand by 25 percent and return flow by 40 percent.

Pricing Pricing policies can help achieve water conservation. The economic incentive for using less water is dependent on consumer attitudes and needs, as reflected in the elasticity of demand. Price elasticity, expressed as (D Q/Q) / (D P/P), measures the change in demand that occurs for a change in price, given the price-

― 145 ―

Table 5.3 Residential Water Demand (Metered, with Devices) Daily Demand or Flow

Per Capita (gallons)

Per Household (gallons)

In-house

57

171

Sprinkling

78

235

Total

135

406

Maximum day

284

851

Sector Average annual

Maximum hour 716

2148

Return flow Sanitary sewer 57

171

Irrigation

3

10

Total

60

181

demand relationship. In terms of residential use, in-house demand is less price-elastic than lawn sprinkling, i.e., with a given price increase the relative change in household use will change (decrease) less than sprinkling usage. Table 5.4 gives some price elasticity values for various categories of demand. Pricing theory and response have been studied by many investigators. Pricing methods have been devised in an effort to reduce demand, but more typically they are used to proportion the costs among consumers.

Peak demand rates and increasing block rates are two pricing structures that can promote water conservation. One procedure is to charge an extra fee for water used above some base allotment. For instance, a residential user may be charged significantly more per unit of water demanded any time his monthly usage exceeds, say, 130 percent of his average winter monthly demand. Increasing block rates charge water users higher rates for additional units above some minimum in one or more steps. As an example of the water savings that can result from a price increase, assuming the elasticities of Table 5.4 are applicable, Table 5.5 shows the residential water demands for a totally

― 146 ―

Table 5.4 Price Elasticities Demand Sector

Elasticity

Source

Residential

–0.225

1

Domestic

–0.26

2

Sprinkling (West)

–0.703

1

Average day

–0.3953

2

0.388

1

Maximum day

Sources: 1. Howe and Linaweaver, reference [24] . 2. Burns et al., reference [25] .

Table 5.5 Change in Daily Residential Water Demand with Price (30,000 population, 10,000 households) Demand Sector

Demand at $0.43

Assumed

Demand at $0.86

Difference (million

per 1,000 gal (million gal) Elasticity

per 1,000 gal (million gal) gal)

Household

1.92

–0.225

1.49

.43

Sprinkling

2.35

–0.395

1.42

.93

Total

4.27

2.91

1.36

Residential

― 147 ― metered community, whose household demand is given in Table 5.3, at water prices of $0.43 per 1,000 gallons and at $0.86 per 1,000 gallons. The net result of the doubling of water prices is a 32 percent reduction in total residential demand.

Revenue After conservation, the utility's demand of 2,910 million gallons (from Table 5.5, at $0.86 per 1000 gallons) would equal $2,502,600, an increase of $666,500, or 36 percent, in revenue. Savings from installation of watersaving devices only, however, with the original price left intact, would result in a $86,000 per year loss in revenue.

Water User Restrictions The imposition of water use restrictions is essentially a short-term method of conserving water. When water supplies reach a level at which officials project that there may not be enough water to meet near-future demand, voluntary restrictions are usually instituted. These may later be made mandatory. The primary difference between this method and the others is that restrictions inconvenience the water consumer, whereas most other methods are designed to inconvenience the customer as little as possible. Although some reduction in demand from restrictions has been reported,[26] the primary effect seems to be a reduction in peak demands.

Implementation The effect of the water conservation programs illustrated in the hypothetical case here, i.e., metering plus devices or doubling the price, is to reduce domestic in-house use from 64 gpcd to 57 gpcd by the use of meters and water-saving devices (if the latter are installed in 50 percent of all residences), and to reduce domestic use to 45 gpcd by doubling the price of water from $0.43 to $0.86/1000 gallons. Lawn sprinkling would be reduced from 78 gpcd to 47 gpcd by the price increase, and overall usage would drop from 142 gpcd to 97 gpcd, a 32 percent decrease. Three cautions to accepting these values need emphasis. These are the assumptions that (1) the elasticities of demand are correct, (2) the demands for in-house and sprinkling use are reasonable, and (3) 50 percent of all households would install and keep in good repair the water-saving devices.

― 148 ― Peak day to average day ratios would probably stay about the same under the conservation programs, with the peak day demand decreasing proportionately with the reduction in average day demand. A loss of revenue would result from installing water-saving devices, but revenue would increase markedly if the price of water was doubled. The combination of both practices would still result in a sizable increase in revenue. Reductions in return flow because of implementation of water conservation practices could have important implications to downstream water users, especially in water-scarce areas of the western United States. One of the more commonly overlooked recommendations in implementing water conservation programs is to use survey research to determine the attitudes and perceptions of the utility's customers toward water conservation, and to attempt to explore possible roles that influentials in the community can play in promoting conservation. In addition to garnering public support, it is necessary for the utility to measure the effectiveness of various conservation programs. Such a procedure compares the expenditures, perhaps on a per capita basis, with the benefits of the program as measured by reduced demand, delays in system expansion, and decreased risks of shortages.

Nonagricultural Conservation as Related to Agriculture From the foregoing discussion it is apparent that urban water conservation by residential, commercial, and industrial users can result in significant reductions in water demand withdrawals. The question now is, what effect can this have on water availability for agriculture? First, it must be admitted that on the broad scale the effect is not large. This is because irrigated agriculture diverts and consumptively uses such a preponderance of the water in the West. Any reductions in the demand for water by municipal or industrial uses would have a relatively slight effect on the overall water availability, even recognizing that cities and industries usually exercise senior appropriation rights. Second, in the growth of municipalities the conversion of irrigated land to urbanized communities can result in less water

― 149 ― being used on an area basis. In addition, the return flows for an equal area of urbanized development will exceed, on a percentage basis, the typical return flow from irrigated agriculture. This indicates that in terms of total water availability, more water is available downstream for irrigators after an upstream irrigated area has been converted to urban development. If conservation is practiced in the urbanized area, this effect will be enhanced. When nonirrigated areas are urbanized, of course, there is no such enhancement, but the depletion effects of urbanization can be decreased through conservation. Lastly, it can be argued that increasing the efficiency-of-use of the nonagricultural sector's water demand can result in benefits to irrigated agriculture, because less water is "tied up" by the municipal utility in storage and reserves, less is actually consumed within the community if on-site control of natural runoff is used to serve public needs, and less water is withdrawn by urban users when an effective conservation program is in operation.

Discussion: Richard C. Tucker It is possible to increase the efficiency of nonagricultural water use and, in the process, produce varying impacts on both water consumption and water withdrawals. J.E. Flack's paper does an excellent job of supporting this proposition and of presenting the various factors involved in pursuing the objective of more efficient water use. The paper presents a very good

categorization of the various kinds of efficiency increases, along with some interesting figures on the net effect of implementing a range of specific measures. Flack's work, along with the excellent references identified, represents a solid contribution to the literature on this subject. The following comments emphasize several of the paper's key points and suggest several areas which need more attention and evaluation. The U.S. Water Resources Council's Second National Water Assessment (1978) presented figures and assumptions about future U.S. water use. The Council estimated that total freshwater withdrawals for all off-stream uses (i.e., irrigation, domestic, manufacturing, mining, and steam electric power generation) in 1975 were 338.5 billion gallons per day (bgd); it projected that withdrawals will decrease to about 307 bgd by the year 2000. This projected decrease is based on assumptions about the implementation of water use efficiencies and recycling from available technology and conservation efforts. The most significant contribution to a reduction in offstream uses was assumed to be in manufacturing; total withdrawals in agriculture and steam electric generation were projected to remain about the same. The Council projected further that consumptive uses averaged 106.6 bgd in 1975 and will increase to 135 bgd by the year 2000. While both the withdrawal and consumptive use figures were aggregations for the entire United States, the figures and their changes from 1975 to 2000 are quite variable from region to region and by type of use. Both water withdrawals and consumption from domestic and commercial uses are predicted to increase considerably, while manufacturing withdrawals are predicted to drop by 60 percent, with consumptive use increasing by about 140 percent. The projections suggest little impact from conservation on domestic use but considerable impact on manufacturing use. Furthermore, manufacturing and mining withdrawals are nearly twice those of the domestic and commercial sectors, and manufacturing and mining consumptive use is expected to grow from equal to double that of domestic and commercial.

― 152 ― Flack's paper presents an excellent overview of the various factors pertaining to water use, but tends to concentrate on the domestic side. While there are potentially worthwhile reductions in all areas, it appears that the greatest opportunity for reductions is in the manufacturing and mining sectors. These areas should be addressed more fully. Certainly another area of great importance to the arid West is water use in the energy sector. In the last several years, many studies have focused on energy development and water supply in the western United States, largely because of the potential development of a major synthetic fuels industry. While most of the studies have concluded that sufficient water is available for a large western U.S. synfuels industry, the water is assumed to be available from irrigated agriculture. Of all possible nonagricultural water uses, water efficiencies in synfuels development and in basic steam electric

power generation may provide the greatest opportunity for total water savings. We have barely scratched the surface of this subject. I am confident that Flack's able research has uncovered the most timely research results available; nevertheless, with few exceptions, his cited references are to research done 8 to 10 years ago—a period when there was minimal effort to study water conservation measures on a national basis, much less implement them. In fact, this recognition led the U.S. General Accounting Office, in its 1979 report Water Resources and the Nation's Water Supply: Issues and Concerns, to state: Although these techniques generally are believed to save water, many have either not been thoroughly studied or had their cost effectiveness evaluated. No centralized data bank or clearinghouse on water conservation measures and techniques exists. Most, if not all, of the efficiency and conservation measures identified in Flack's paper require no significant lifestyle changes or alterations in basic industrial business practices. What could be achieved with a more concerted attack on water use inefficiencies? I believe that a continuing consciousness about water use—in combination with pricing—is necessary to have any dramatic effects. Flack presents an especially good discussion of the whole area of reuse and return flows. It reminded me of an incident that occurred some years ago while I was attending an ASCE meeting in Memphis. I was sitting in my hotel lobby, and an elderly gentleman sitting next to me suddenly said, "Young man, I

― 153 ― understand this is a conference on water, and I just heard that the people here take their drinking water from the Mississippi River. But did you know that St. Louis, which is upstream, dumps its sewage into the Mississippi River! This is just dreadful!" I really spoiled his day when I told him the people of Memphis got the same "present" from Pittsburgh, Cincinnati, Omaha, and a number of other cities to the north. Our national awareness of pollution control has changed considerably over the last several years, and few people would be surprised at such a statement today. But we still haven't gone far enough in alerting people to the need to conserve water, possibly because the national emphasis on energy conservation has diverted attention from the issues of water use. I am confident we will achieve the necessary water use savings to ensure a safe and adequate water supply for the future. We will undoubtedly, however, have to modify our perceptions of "need," heighten our national

consciousness about water use, and be prepared to modify our lifestyles and institutions to be more compatible with the realities of a finite resource. We need to heed the results of our own studies and develop a more detailed assessment of the impacts and cost effectiveness of implementing a multifaceted water conservation program on a regional and subregional basis. Increasing the efficiency of nonagricultural water use represents one means to free water for other uses, and savings on the order of 20 to 40 percent seem realistic. Will this have any significant impact on increasing water availability for irrigated agriculture? Compared to the water savings which can be achieved in irrigated agriculture itself, probably not.

Discussion: Dennis C. Williams The paper by J.E. Flack discusses the potential of water reclamation to augment existing water supplies and describes a wide range of water conservation measures which can reduce water demand in the urban sector. The following comments focus on the feasibility and effectiveness of some of the measures suggested by Flack from the perspective of a municipal utility that has been actively involved in promoting and implementing water conservation for a number of years.

― 154 ―

Wastewater Reclamation Wastewater Reuse Wastewater reclamation and reuse represents a potentially important supplemental source of water for urban areas. Nearterm uses for reclaimed water include landscape irrigation and industrial process water. Groundwater recharge using reclaimed water to replenish groundwater supplies is a potential use which is currently restricted in California due to health-related concerns. Studies presently underway are expected to lead to appropriate health standards for groundwater recharge. An important factor affecting feasibility is the cost of distribution facilities (storage, pumps, and pipelines) needed to supply reclaimed water from the treatment plant to the place of use. The Orange and Los Angeles Counties Water Reuse Study is a three-year, $4 million study nearing completion which has identified more than 30 potential projects in the study area with a total yield of more than 200,000 acre-feet.

The unit cost for water developed from these projects varies from $40 per acre-foot to more than $900 per acre-foot (1980 dollars). For purposes of cost comparison, Los Angeles currently purchases supplemental water from the Metropolitan Water District of Southern California at a cost of $140 per acre-foot.

Dual Systems A few areas have successfully installed dual pipeline systems to deliver potable water to homeowners and to deliver reclaimed water for irrigation purposes. This approach may be feasible in a carefully planned developing area where new streets and residences are being constructed, wastewater treatment facilities are nearby, and there are substantial greenbelt and commonly irrigated landscaped areas such as condominium and townhome developments. One example of a successful project is operated by the Irvine Ranch County Water District in Irvine, California. However, dual systems are generally not practical in established areas with typical single-family residences and an existing potable water distribution system. The cost of installing and maintaining a separate distribution system for reclaimed water would be excessive.

― 155 ―

Water Conservation Measures Water-Saving Household Devices Water meters, low-flow showerheads, low-flush toilets, and other structural methods can be very effective in reducing water use without inconvenience on the part of the customer. For example, a low-flow toilet uses about onethird less water than a standard toilet (5.5 vs. 3.5 gallons per flush). Most water utilities in California are fully metered, and homes built since 1978 are required to be equipped with low-flush toilets. In addition, all showerheads sold in the state since 1979 are required to be low-flow. Los Angeles and many other communities have provided free water conservation retrofit kits to residential customers. These kits typically include a plastic bag water displacement device for toilets, flow-reducing washers for showerheads, dye tablets to detect toilet leaks, installation instructions, and other water conservation tips. When mailed to the household, the installation rates range from 25 percent to 35 percent for the toilet devices, and 10 percent to 18 percent for the shower devices.

Water Pricing While it is generally recognized that increasing the price of water will tend to decrease its use, water pricing as a conservation tool poses a number of problems that must be considered by the utility. First, it is very difficult to estimate the impact that higher prices will have on water use and revenue to the utility. There have been many studies on the elasticity of water with the results varying significantly. Second, the determination of water rates must consider many factors, including revenue requirements, conservation, and the allocation of costs equitably among various customer classes. The rate structure of a municipal utility is generally subject to approval by a city council or other authority elected by the public. Local residents and businesses can be expected to oppose rate proposals that result in significantly increased costs to one customer class or group.

Industrial Conservation There appears to be significant potential for conserving water in the industrial sector through recycling and process changes. The City of Los Angeles has implemented a water conservation awards program to recognize commercial and industrial

― 156 ― customers who have shown outstanding conservation achievements. A variety of conservation measures ranging from innovating water recycling techniques to simple common sense approaches have led to water use reductions exceeding 50 percent for a number of businesses.

Leak Detection A number of utilities in California conduct leak detection programs as part of their water conservation effort. These programs typically use specialized monitoring equipment to "listen" for leaks in the distribution system. An effective leak detection and repair program can result in a variety of benefits including water savings, increased public awareness of the need to conserve, and customer goodwill when leaks found on private property are brought to the customers' attention.

Estimates of Conservation Savings Flack discusses in some detail an approach for estimating savings associated with implementing conservation measures. While an estimate of savings may be useful, it is important to recognize that estimates can vary substantially

depending on the assumptions made. For example, savings associated with the installation of low-flow showerheads have been estimated to be as much as 12 gallons per person per day and as little as 3 gallons per person per day, or a range of 300 percent. Brown and Caldwell, Consulting Engineers, are currently conducting a number of water conservation demonstration projects designed to document water savings associated with various conservation measures. The results should help improve the reliability of savings estimates.

― 157 ―

Chapter 6— Coping with Salinity by Jan van Schilfgaarde and J.D. Rhoades

Abstract Four independent management strategies are identified to cope with increasing levels of salinity. First, saline springs or other point sources of saline water can be intercepted; the water then can be evaporated, desalted, and reused, or diverted for use in industrial applications. Second, the amount of water applied for irrigation can be reduced, thus lessening the amount that seeps through the soil and reducing the salt load in return flows. Third, somewhat saline water can be used as a source of irrigation water for salt-tolerant crops. Such use reduces the amount of brackish water needing disposal and provides a substitute water supply. Fourth, the cropping pattern can be changed by choosing tolerant rather than sensitive crops. Through plant breeding more tolerant varieties of common species may become available. None of these options is without cost, and all have socioeconomic as well as technical aspects.

The primary theme of this volume is how to deal with water shortages. Water supplies, however, cannot be viewed solely in terms of quantity; clearly, the quality of the water must be considered as well. Water quality is nevertheless such a broad subject, that a restricted definition must be chosen for this discussion. The leading water quality parameter that affects irrigation agriculture no doubt is salinity; we will therefore focus our analysis on salinity-irrigation interactions and associated water management options.

Clearly agriculture is affected by, and affects, water quality in terms of pesticides, of nitrates and phosphorus, of heavy metals, and/or of sediment. The list could be extended, but none of these is uniquely tied to irrigation in the semiarid West, or is directly affected by diminishing water supplies. Salinity, however, is. As water supplies become more limiting, the use of sewage water for irrigation becomes a more important option; in fact 25 percent

― 158 ― (109 m3 /yr) is reused in California already.[1] Therefore, we treat this subject briefly in the context of alternate water supplies. Industrial development, such as the extraction of oil from shale, not only would compete with agriculture for water supplies, but also could well result in quality degradation of remaining waters; such degradation, however, would be dominated by an increase in salinity. Although salinity problems are indeed aggravated directly as irrigation water supplies are diminished, salinity per se is not restricted to irrigated lands. Salinity problems are widespread across the world. Although the literature is extensive, good statistics on the extent are hard to find. Szabolcs,[2] for example, implied that there are some 30 million hectares of salt-affected soils in Europe; and Shalhevet and Kamburov[3] estimated, from a mail survey, that worldwide 50 million hectares of cultivated land are salt affected, exclusive of the USSR. For the U.S., a recurring estimate is that up to one third of irrigated land is salt-affected, but reliable data are lacking.[4] Severe salinity problems are encountered along the Pecos River and the Rio Grande; it has been estimated that over one-third of the salt load of the Colorado River can be attributed to irrigation; and in California, salinity is a fact of life in the Imperial Valley, the lower San Joaquin, and elsewhere. Thus salinity problems are widespread, even if exact statistics are not available. The thesis of this discussion is that salinity is closely tied to water conservation measures. Before delving into options for coping with decreasing quantities of increasingly saline irrigation water, it seems appropriate to define some terms and to orient readers who may be less than fully conversant with salinity issues. The term "salinity", when applied to water, refers to inorganic ions (or compounds) in solution. Though an appropriate method for expressing salinity is to list the concentrations of the primary cations and anions in, say, mol L–1 , a common shorthand is to use concentration of total dissolved solids on a mass basis, in mg L–1 . With all its obvious shortcomings, this custom emphasizes the view that, as a first approximation, plants (but not soils) respond to total salt concentration, more than to its specific constituents. For reasons of analytical convenience, an equally common unit

is electrical conductivity, in terms of S m–1 . A rough conversion (rough because it depends on ionic composition and concentration) is 1 dS m–1 = 650 mg L–1 .

― 159 ― A similar usage has developed for soils, where the variable of interest is the salt concentration of the soil solution. Unfortunately, the soil water content changes all the time and so does the soil solution composition. In an attempt to standardize "soil salinity", there was introduced the electrical conductivity of an extract of a saturated paste made from a soil sample. The primary point here is that soil salinity is not an easily defined, single-valued parameter. Furthermore, soil properties are affected by the composition of the soil solution and thus, in turn, of the irrigation water. Though the interactions among soil properties and the salts in solution are numerous—and dependent on mineralogy—it is sufficient here to stress the adverse effects of sodium. At high levels of sodium relative to divalent cations in the soil solution and thus, at equilibrium, on the exchange complex, clay minerals in soils tend to swell, and aggregates tend to disperse under conditions of low total salt concentration. Whether from swelling or from dispersion, the soil hydraulic conductivity is reduced, and the surface tends to crust. Thus the ability of the soil to infiltrate and transmit water can be severely reduced. It is the relative amount of sodium on the soil and the total amount of salt in the water that are important. High total electrolyte concentrations tend to increase a soil's stability; thus we distinguish between saline soils and sodic soils, saline waters and sodic waters. Salinity is an inescapable concomitant of irrigation in arid areas. The water in pure mountain streams picks up salts as it moves over and through rocks. Part of the water diverted for irrigation evaporates, leaving the salts in a smaller volume of drainage water. This drainage water, in turn, may dissolve or displace salts of geologic origin. Evaporation also takes place from open water surfaces, such as lakes and storage reservoirs. In all, natural processes are accelerated by man's impact, and water generally becomes more and more saline as one moves downstream in the hydrologic system. To avoid a continuing increase in salinity in the soil water, there must be adequate soil drainage to remove the excess salts accumulating from irrigation. Drainage is also required to avoid water logging, or a high water table, which in turn increases the salinity problem. Hence the concept of salt balance: the amount of dissolved salt brought into an area in irrigation water must be matched by that removed by the drainage system, if salination is to be avoided. The salt balance concept is often misused and

― 160 ― misinterpreted.[5] Qualitatively, however, it is sound—and helpful in visualizing the situation. The reason we irrigate is to increase the production of agricultural crops, but salinity tends to decrease crop yield. A definitive description of what is meant by tolerance of plants to salinity is difficult to construct. Nonetheless, some crop plants are more tolerant to salt-induced stress than others. As with other stresses, plants expend energy to overcome the stumbling blocks they encounter. For example, it requires more energy to extract water out of a concentrated soil solution than out of a dilute solution, and for the plant cell there is a cost associated with manufacturing (or secreting) the compounds needed for osmoregulation. Though the details are complicated— if understood at all—a helpful working hypothesis for operational purposes is that plants respond to the total potential of the water in the rootzone, i.e., the sum of the osmotic potential (salt stress) and the matric potential (soil water deficit). The tolerance of crops to salinity is most readily expressed in terms of a threshold salinity (preferably in the soil solution) below which no adverse effect on yield is noted, and a rate of decrease in yield with increasing salinity beyond the threshold.[6] Though these indices imply an absolute tolerance, we prefer to think of them as relative values useful in ranking the tolerance of various crops. The values obtained depend on the management practices used and the environment in which the crops are grown; they do not take account of differences in sensitivity at various growth stages, such as germination versus grain filling. Aside from tolerance to unspecified (and presumed mixed) salts, we must sometimes be concerned with toxicity of specific ions. Some reports of Na toxicity may well have been misinterpretations of Ca deficiencies or salinity excesses. However, sensitivities of woody plants to chlorides and of almost all plants to boron are factors of concern. Returning to our main theme, we recognize that increased demands on a limited water supply tend to increase the salinity in the system. Because of increased use of water out of the Colorado, contribution from saline springs is a larger percentage of the remaining flow; recycling groundwater in a closed basin increases salinity; expanded irrigation in the Central Valley of California increases the need for disposal of saline drainage water. Many different situations are encountered, yet the end result is generally the same: water development in arid regions leads to increasing salinity problems. The question is, what

― 161 ― options exist for reducing the threat of salination? We shall consider several types of situations and attempt to illustrate them with some examples.

Management Options A number of options are open to us to minimize the adverse effects of salinity in irrigation in particular, and in water resource use more generally. For purposes of discussion, we here group these options into four classes, recognizing that they are not fully independent or, for that matter, truly parallel.

Diversion or Desalting First, we consider intercepting brackish water and diverting it out of the system, or desalting it for reuse. The latter part of this option, desalting, is one we can dispose of briefly. Though technically clearly feasible, and no doubt appropriate under special circumstances, we do not see desalting, now or in the foreseeable future, as a viable option for obtaining water for irrigation. Desalting is planned for the drainage water from the WelltonMohawk Irrigation District in Arizona, but the decision in that case was not based on best resource use or on economics.[7] The Department of Interior also has plans for desalting brackish water at LaVerkin Springs in Utah and Glenwood-Dotsero Springs in Colorado at costs estimated to be three times the benefits.[8] In California, there is continued interest in use of desalting technology in the Central Valley. Although we are not adequately informed to assess the progress, it is doubtful that the economics would come out very differently from those experienced by the U.S. Bureau of Reclamation. The other half of this option, diverting brackish water out of the system, offers some interesting possibilities. Several years ago, the Kern County Water Agency considered the use of brackish drainage water (around 6,000 mg L–1 ) for use as cooling water in a power plant. This option evaporated when, for other reasons, plans for the power plant were dropped. More recently, in the special report just cited, USBR engineers concluded that use of brackish water for power plant cooling offered substantial opportunities for reducing salinity in the Colorado River. Another interesting option that emerged was transport of coal in a slurry or—an intriguing concept— hydraulic transport of bagged coal through a pipeline. California hardly has the option to transport

― 162 ― coal to its shores, but Colorado well may be able to use some of its brackish

water in this manner. None of these uses deals directly with agriculture. Their implementation would affect agriculture by reducing the salinity of the water remaining, or by reducing the volume of drainage water needing disposal. Still, they are not central to the consideration of agricultural water quality. Thus we will not elaborate on them any further.

Decreasing Irrigation Water Use Claims are often made that irrigation water is used wastefully and that irrigation efficiencies can be increased substantially. Such claims must be put in proper perspective. Since on-farm water conservation is the topic of the next several chapters, we consider here only those aspects that deal specifically with water quality. Often the inefficiency that is observed is excessive tailwater. Though tailwater may well have other negative impacts, it is not likely to affect significantly the salinity of the receiving waters. On the other hand, excessive seepage (in-field deep percolation or seepage from ditches and laterals), while less obvious, can and often does affect downstream water quality in one of several ways. It may displace saline groundwater that has accumulated over time. Probably this is the case in the southwestern part of the Palo Verde Irrigation District, called the Palo Verde Subarea. It has been estimated that an increase in on-farm irrigation efficiency to 60 percent initially would reduce the salt discharge from the 4,000 hectares in this area by about 60,000 tonnes annually, or the salinity at Imperial Dam by about 8 mg L–1 .[9] In other cases reducing deep seepage may reduce the dissolution of salts from underlying formations. In the Grand Valley of Colorado, studies indicate that the salt loading of the Colorado River can be reduced by about 400,000 tonnes annually by decreasing the amount of irrigation return flow and conveyance system seepage moving through underlying saline substrata. Such a reduction would result in a decrease of the salinity of the river at Imperial Dam of approximately 43 mg L–1 .[10] Since current estimates, based on detailed economic studies, give the impact of a change of 1 mg L–1 at Imperial Dam as approximately $500,000 per year,[11] the economic impact of the Grand Valley project is indeed substantial. Changes in leaching fraction—i.e., the fraction of the irrigation water infiltrated that becomes deep seepage—can affect the

― 163 ―

salt regime in another fashion. As the electrolyte concentration of soil water is increased by evapotranspiration, the tendency of water to dissolve salts shifts towards a tendency to precipitate salts. Thus a reduction in leaching fraction—which leads to increased salinity of the drainage fraction—tends to reduce the total salt load in the drainage water. This principle, illustrated in earlier papers,[12] was applied to a set of hypothetical river and groundwater basins by Rhoades and Suarez[13] and by Suarez and van Genuchten.[14] They demonstrated that the effect of reduced leaching on the salt regime depends greatly on the nature of the irrigation water, on whether the receiving water is a groundwater or surface water and on certain hydrogeologic conditions. Reduced leaching is no panacea, but in the proper circumstances, it can have significant impact on the quality of the receiving waters; it always reduces the salt load of the drainage water that percolates below the rootzone. In the short run, before equilibrium conditions are obtained, the effects of salt precipitation can be far greater than predicted in the above studies.[15] Attempts have been made to extend the modeling of these systems to take into account irrigation scheduling and crop response. An example is the work of Yaron et al.[16] Unfortunately, the data base available is not yet sufficient to make such models very useful. The concept of increasing irrigation efficiency by reduced leaching is being applied effectively in various areas. Examples are the Wellton-Mohawk area of Arizona and the Grand Valley of Colorado cited above. To put the matter in perspective, however, a number of reservations must be addressed. For example, though it is expected that reducing the water applied in the 4,000hectare Palo Verde Subarea (cited above) would reduce the salinity at Imperial Dam, "improving" the currently very low water application efficiency in the remainder of the 36,000-hectare District is not expected to affect downstream water quality because there is no evidence of salt stored underground in that area and salt should not precipitate from the applied water in this case.[17] Presumably, the economic efficiency of water management at present is quite high there. Reduced leaching implies a lower margin for error in providing adequate salinity control. Thus it calls for a more uniform, better managed system of irrigation and, especially when pushed to the limit, requires some system of monitoring to avoid crop yield reductions or adverse salt buildup in the soil. Precise and innovative irrigation management is aided by recent developments in

― 164 ― irrigation technology, such as linear-move sprinklers, more reliable trickle systems, and laser-graded level border systems. Regular monitoring of salinity status is made feasible by developments in instrumentation and

techniques originating at the U.S. Salinity Laboratory in Riverside.[18] Reduced leaching and controlled seepage will reduce the drainage requirement and, in the absence of adequate drainage, postpone the day of reckoning. As an example of the first situation, it is likely that the alleged need for increased drainage intensity in Imperial Valley now compared to 20 years ago is due to excess canal seepage; the second is illustrated by the concerns in Fresno and Kern counties, California, with rising water tables.[19]

Use or Reuse of Salty Water In the western U.S., water supplies have been relatively plentiful and generally of excellent quality. As the pressure on water resources increases, there is increasing reason to consider use of more saline water in agriculture. Rhoades[20] pointed out that most of the typical drainage waters in the U.S. have potential value for irrigation, and presented results of detailed calculations to illustrate this observation. Our interest, however, is not so much in drainage waters per se, but in water with increasing levels of salinity. The number of documented reports on the successful use of brackish water for irrigation is relatively limited. Claims that seawater can be used for crop production[21] are far from convincing. Some other claims, such as 10 tons per hectare–1 yield of alfalfa with 12,500 mg L–1 water in the USSR[22] may well be tainted by poor translation or misunderstanding. Data on cotton irrigation (p. 166) are more consistent with U.S. experience; comparing long-term irrigation in Uzbekistan with drainage water (5-6,000 mg L–1 TDS), mixed water (2-3,000 mg L–1 ) and canal water (