IMPACTS OF A SEVERE SUSTAINED DROUGHT ON COLORADO RWER WATER RESOURCES1

ABSTRACT: The impacts of a severe sustained drought on Colorado River system water resources were investigated by simulating the physical and institutional constraints within the Colorado River Basin and testing the response of the system to different hydrologic scenarios. Simulations using Hydrosphere's Colorado River Model compared a 38-year severe sustained drought derived from 500 years of reconstructed streamflows for the Colorado River basin with a 38-year streamflow trace extracted from the recent historic record. The impacts of the severe drought on streamflows, water allocation, storage, hydropower generation, and salinity were assessed. Estimated deliveries to consumptive uses in the Upper Basin states of Colorado, Utah, Wyoming, New Mexico, and northern Arizona were heavily affected by the severe drought, while the Lower Basin states of California, Nevada, and Arizona suffered only slight shortages. Upper Basin reservoirs and streamflows were also more heavily affected than those in the Lower Basin by the severe drought. System-wide, total hydropower generation was 84 percent less in the drought scenario than in the historical stream-flow scenario. Annual, flow-weighted salinity below Lake Mead exceeded 1200 ppm for six years during the deepest portion of the severe drought. The salinity levels in the historical hydrology scenario never exceeded 1100 ppm.     

MITIGATING IMPACTS OF A SEVERE SUSTAINED DROUGHT ON COLORADO RWER WATER RESOURCES1

ABSTRACT: We evaluated the effects of institutional responses developed for coping with a severe sustained drought (SSD) in the Colorado River Basin on selected system variables using a SSD inflow hydrology derived from the drought which occurred in the Colorado River basin from 1579–1616. Institutional responses considered are reverse equalization, salinity reduction, minimum flow requirements, and temporary suspension of the delivery obligation of the Colorado River Compact. Selected system variables (reservoir contents, streamflows, consumptive uses, salinity, and power generation) from scenarios incorporating the drought-coping responses were compared to those from Baseline conditions using the current operating criteria. The coping responses successfully mitigated some impacts of the SSD on consumptive uses in the Upper Basin with only slight impacts on consumptive uses in the Lower Basin, and successfully maintained specified minimum streamflows throughout the drought with no apparent effect on consumptive uses. The impacts of the coping responses on other system variables were not as clear cut. We also assessed the effects of the drought-coping responses to normal and wet hydrologic conditions to determine if they were overly conservative. The results show that the rules would have inconsequential effects on the system during normal and wet years.     

SOCIAL IMPLICATIONS OF SEVERE SUSTAINED DROUGHT CASE STUDIES IN CALIFORNIA AND COLORADO1

ABSTRACT: Survey data collected in the San Joaquin Valley of southern California and the Grand Valley of western Colorado reveal that residents of both areas believe that a severe sustained drought is likely to occur within the next 20–25 years and that their communities would be seriously impacted by such an event. Although a severe sustained drought affecting the Colorado River Basin would cause major economic and social disruptions in these and other communities, residents express little support for water management alternatives that would require significant shifts in economic development activities or in water use and allocation patterns. In particular, residents of these areas express little support for strategies such as construction and growth moratoriums, mandatory water conservation programs, water transfers from low-to high-population areas, water marketing, or reallocations of water from agricultural to municipal/industrial uses. This rejection of water management strategies that would require a departure from “business as usual” with respect to water use and allocations severely restricts the capacity of these and similar communities to respond effectively should a severe sustained drought occur.     

COPING WITH A SEVERE SUSTAINED DROUGHT ON THE COLORADO RWER: INTRODUCTION AND OVERVIEW1

ABSTRACT: In arid regions of rapid economic and population growth, adverse effects of droughts are likely to be increasingly serious. This article presents an introduction and overview of the papers collected in this special issue of the Water Resources Bulletin. The papers report on the second phase of a study of the impacts of and responses to a potential severe sustained drought in the Colorado River Basin in the southwestern U.S. The analyses were performed by a consortium of researchers from universities and the private sector located throughout the Basin. Tree ring studies suggest that droughts of duration and magnitude much more serious than any found in the modern records probably occurred in the Basin during earlier centuries. Taking the present-day configuration of the storage and diversion structures and the economic conditions in the Basin as the base-point, the general objectives of the study are three: first, to define a representative Severe Sustained Drought (SSD) and assess its hydrologic impacts; second, to forecast the economic, social and environmental impacts on the southwestern U.S.; and finally, to assess alternative institutional arrangements for coping with an SSD. The evaluation of impacts and policies was conducted with two distinct modeling approaches. One involved hydrologic-economic optimization modeling where water allocation institutions are decision variables. The second was a simulation-gaming approach which allowed “players” representing each basin state to interact in a real-time decision making mode in response to the unfolding drought.     

MANAGING THE COLORADO RIVER IN A SEVERE SUSTAINED DROUGHT AN EVALUATION OF INSTITUTIONAL OPTIONS1

ABSTRACT: This paper presents a summary of the findings and recommendations of the studies of severe, sustained drought reported in this special issue. The management facilities and institutions were found to be effective in protecting consumptive water users against drought, but much less effective in protecting nonconsumptive uses. Changes in intrastate water management were found to be effective in reducing the monetary value of damages, through reallocating shortages to low-valued uses, while only water banking and water marketing, among the possible interstate rule changes, were similarly effective. Players representing the basin states and the federal government in three gaming experiments were unable to agree upon and effect major changes in operating rules. The conclusions are (1) that nonconsumptive water uses are highly vulnerable to drought, (2) that consumptive uses are well-protected, (3) that drought risk is greatest in the Upper Basin, (4) that the Lower Basin suffers from chronic water shortage but bears little drought risk, (5) that opportunities exist for win-win rule changes, (6) that such rule changes are extremely difficult to make, and (7) that intrastate drought management is very effective ^m in reducing potential damages.     

THE TREE-RING RECORD OF SEVERE SUSTAINED DROUGHT1

ABSTRACT: Frequent and persistent droughts exacerbate the problems caused by the inherent scarcity of water in the semiarid to arid parts of the southwestern United States. The occurrence of drought is driven by climatic variability, which for years before about the beginning of the 20th century in the Southwest must be inferred from proxy records. As part of a multidisciplinary study of the potential hydrologic impact of severe sustained drought on the Colorado River, the physical basis and limitations of tree rings as indicators of severe sustained drought are reviewed, and tree-ring data are analyzed to delineate a “worst-case” drought scenario for the Upper Colorado River Basin (UCRB). Runs analysis of a 121-site tree-ring network, 1600–1962, identifies a four-year drought in the 1660s as the longest-duration large-scale drought in the Southwest in the recent tree-ring record. Longer tree-ring records suggest a much longer and more severe drought in 1579–1598. The regression estimate of the mean annual Colorado River flow for this period is 10.95 million acre-feet, or 81 percent of the long-term mean. The estimated flows for the 1500s should be used with caution in impact studies because sample size is small and some reconstructed values are extrapolations.     

HISTORICAL AND SOCIOPOLITICAL CONTEXT OF THE WESTERN WATERSHEDS MOVEMENT1

ABSTRACT: The 1990s have featured a rapid proliferation of “watershed initiatives” in the western United States and elsewhere. Watershed initiatives are ad hoc, voluntary associations typically featuring both governmental and non-governmental actors organized together to collaboratively seek new strategies for addressing water and related natural resource problems at physically relevant regional scales. These efforts are a response to historical and sociopolitical trends that have resulted in increasingly ineffective forums and processes of resource management decision-making, and that have subordinated the role of local stakeholders in problem-solving efforts. In most cases, watershed initiatives appear to provide a pragmatic vehicle for resource managers and stakeholders to address common concerns in a more efficient manner than is otherwise possible, and as such, deserve further application and continued support.     

INSTITUTIONAL OPTIONS FOR THE COLORADO RIVER1

ABSTRACT: In many interstate river basins, the institutional arrangements for the governance and management of the shared water resource are not adequately designed to effectively address the many political, legal, social, and economic issues that arise when the demands on the resource exceed the available supplies. Even under normal hydrologic conditions, this problem is frequently seen in the Colorado River Basin. During severe sustained drought, it is likely that the deficiencies of the existing arrangements would present a formidable barrier to an effective drought response, interfering with efforts to quickly and efficiently conserve and reallocate available supplies to support a variety of critical needs. In the United States, several types of regional arrangements are seen for the administration of interstate water resources. These arrangements include compact commissions, interstate councils, basin interagency committees, interagency-interstate commissions, federal-interstate compact commissions, federal regional agencies, and the single federal administrator. Of these options, the federal-interstate compact commission is the most appropriate arrangement for correcting the current deficiencies of the Colorado River institution, under all hydrologic conditions.     

RESPONDING TO DROUGHT: COMMON THREADS FROM THE PAST,VISIONS FOR THE FUTURE1

ABSTRACT: A number of studies conducted since the late 1970s have evaluated state and federal responses to drought in the United States. Each of these studies identified a number of key issues and impediments that needed to be addressed to improve the nation's ability to cope with and prepare for future episodes of drought. A content analysis of these studies was performed to identify common threads in their recommendations. The premise of this analysis was that the series of drought years that occurred between 1986 and 1992 and recurred between 1994 and 1996 increased awareness of our nation's continuing and apparent growing vulnerability to drought. This awareness has led to greater consensus among principal constituents and stakeholders, and also a greater sense of urgency to implement actions now to lessen vulnerability. The results of this analysis revealed that several themes recur: create an integrated national drought policy and plan; develop an integrated national climate monitoring (drought watch) system; incorporate drought in FEMA's National Mitigation Strategy; conduct post-drought audits of response efforts; establish regional drought forums; and encourage development of state drought mitigation plans.     

THE WESTERN WATER COMMISSION: WATERSHED MANAGEMENT RECEIVES THE AVI'ENTION OF A NEW GENERATION1

ABSTRACT: Our nation periodically reviews national water policy and considers its directions for the future. The most recent examination was directed at the western United States and the role of the federal agencies in meeting its needs. The West is no longer the frontier, but rather contains vibrant cities and booming centers of international trade, as well as tourism, mineral, and oil and gas development, agricultural, and other development. In this changing environment, federal water policies need to consider the long term sustainability of the West, provide justice to Indian tribes, protect the rivers and ecosystems on which natural systems depend, balance the needs of newcomers with those of agricultural users and communities, and meet a myriad of other demands. The Western Water Policy Review Advisory Commission has just concluded its review of these issues and issued its report. Key among the recommendations is the need to coordinate federal agencies at the basin and watershed level and make government more responsive to local needs, but within a framework that includes national mandates. The Commission's recommendations are presented here, along with some of the issues that surrounded the operations of the Commission.     

THE IMPACTS OF CLIMATIC CHANGES FOR WATER RESOURCES OF THE COLORADO AND SACRAMENTO-SAN JOAQUIN RIVER BASINS1

ABSTRACT: A wide variety of regional assessments of the water-related impacts of climatic change have been done over the past two decades, using different methods, approaches, climate models, and assumptions. As part of the Water Sector research for the National Assessment of the Implications of Climatic Variability and Change for the United States, several major summaries have been prepared, looking at the differences and similarities in results among regional research projects. Two such summaries are presented here, for the Colorado River Basin and the Sacramento River Basin. Both of these watersheds are vitally important to the social, economic, and ecological character of their regions; both are large snowmelt-driven basins; both have extensive and complex water management systems in place; and both have had numerous, independent studies done on them. This review analyzes the models, methods, climate assumptions, and conclusions from these studies, and places them in the context of the new climate scenarios developed for the National Assessment. Some significant and consistent impacts have been identified for these basins, across a wide range of potential climate changes. Among the most important is the shift in the timing of runoff that results from changes in snowfall and snowmelt dynamics. This shift has been seen in every regional result across these two basins despite differences in models and climate change assumptions. The implications of these impacts for water management, planning, and policy are discussed.     

RATES,RIGHTS, AND REGIONAL PLANNING IN THE METROPOLITAN WATER DISTRICT OF SOUTHERN CALIFORNIA1

ABSTRACT: The Metropolitan Water District of Southern California has for more than 70 years shaped the development of an immense urban region. The district's current strategic planning process therefore could have substantial effects on regional water planning and management. The rate restructuring phase of the planning process has produced a multiple component, cost of service based framework. This paper describes that framework as well as some criticisms that have been directed toward it. The rate restructuring was shaped, and for a while stalled, by old disputes among member agencies over rights to water supplied by Metropolitan. That controversy has diverted attention from the resource management implications of the rate structure. This paper presents an alternative future focused approach to regional integrated water resource planning for Southern California based on projections of current trends and anticipation of future events. This discussion raises the question of how regional integrated water resources planning of this sort may proceed, and what role Metropolitan will play in that process.     

THE (POLITICAL) SCIENCE OF WATERSHED MANAGEMENT IN THE ECOSYSTEM AGE1

ABSTRACT: Ecosystem management has become an important unifying theme for environmental policy in the past decade. Whereas the science of ecosystem dynamics suggests that it will remain difficult to define ecosystem borders and all of the natural and anthropogenic effects that influence them, the politics of ecosystem management require that a national ecosystem delineation standard be adopted. Moreover, a political framework for ecosystem management decision making must be designed in such a way as to complement the hierarchical, interrelated nature of ecosystems generally. This paper advocates that a watershed-based ecosystem delineation standard is the most politically suitable because it will be easily understood by the public and watersheds have a long history as a medium of environmental policy. The paper then proposes that the political framework for watershed-based ecosystem management must depend heavily on state and local autonomy, subject to federally prescribed standards and goals. The Coastal Zone Management Act provides a model for how a national ecosystem management policy can work within state and local watershed cultures and economies.     

ADAPTIVE MANAGEMENT OF LARGE RIVERS WITH SPECIAL REFERENCE TO THE MISSOURI RIVER1

ABSTRACT: The technocratic approach for managing the Missouri River and other large rivers is not effective in resolving conflicts among competing uses of water and dealing with uncertainty about how river ecosystems respond to alternative management actions. Adaptive management offers an alternative way to address these and other issues. It has the potential to alleviate management gridlock and provide lasting solutions to management of the Missouri River and other large river ecosystems. In passive adaptive management, simulation models and expert judgment are combined to select a preferred management action. While passive adaptive management is relatively simple and inexpensive to use, it does not necessarily provide reliable information for making management decisions. Active adaptive management uses statistically designed experiments to test assumptions or hypotheses about ecosystem responses to management actions. It is best carried out by a collaborative working group. Active adaptive management has several advantages, but the inability to satisfy certain prerequisites for successful application makes it more difficult to implement in large river ecosystems. A second‐best approach is proposed here to select, implement, monitor, and evaluate a preferred management action and retain that action provided ecological conditions improve and socioeconomic indicators do not fall below established acceptability limits.     

HYDROLOGIC SCENARIOS FOR SEVERE SUSTAINED DROUGHT IN THE SOUTHWESTERN UNITED STATES1

ABSTRACT: This paper considers the risk of drought and develops drought scenarios for use in the study of severe sustained drought in the Southwestern United States. The focus is on the Colorado River Basin and regions to which Colorado River water is exported, especially southern California, which depends on water from the Colorado River. Drought scenarios are developed using estimates of unimpaired historic streamflow as well as reconstructions of streamflow based on tree ring widths. Drought scenarios in the Colorado River Basin are defined on the basis of annual flow at Lees Ferry. The risk, in terms of return period, of the drought scenarios developed, is assessed using stochastic models.     

ASSESSING ENVIRONMENTAL EFFECTS OF SEVERE SUSTAINED DROUGHT1

ABSTRACT: Evaluation criteria for reservoir and stream resources were developed to provide decision makers with feedback on environmental consequences of water allocation decisions under conditions of severe sustained drought within the Colorado River Basin by using the AZCOL gaming simulation model. Seven categories of flow dependent resources were identified which highlight resource states associated with reservoirs or river reaches within the AZCOL model. AZCOL directly simulates impact of water management decisions on five resource categories: threatened, endangered or sensitive fish; native nonlisted fish; wetland and riparian elements; national or state wildlife refuges; and hatcheries or other flow dependent facilities. Two additional categories - cold and warm water sport fish - are not modeled explicitly but are incorporated in the evaluation of monetary benefits from recreation on Colorado River waters. Each resource category was characterized at each time step in the simulation according to one of four environmental states: stable, threatened, endangered, or extirpated. Changes in resource states were modeled by time and flow-dependent decision criteria tied to either reservoir level or stream flows within the AZCOL model structure. Gaming results using the AZCOL model indicate environmental impacts would be substantial and that water allocation decisions directly impacted environmental resource states.     

INTEGRATED RIVER BASIN OPTIMIZATION: MODELING ECONOMIC AND HYDROLOGIC INTERDEPENDENCE1

ABSTRACT: This paper presents an integrated optimal control model that optimizes economic performance of reservoir management in watersheds in which there are significant economic and hydrologic interdependencies. The model is solved using the General Algebraic Modeling System (GAMS). Results show that application of this model to New Mexico's Rio Chama basin can increase total system benefits over historical benefits by exploiting complementarities between hydroelectricity production, instream recreation, and downstream lake recreation.     

BUILDING THE AGENDA FOR INSTITUTIONAL RESEARCH IN WATER RESOURCE MANAGEMENT1

ABSTRACT: This paper pursues more specifically the recommendations of a recent National Research Council report recommending greater attention to research on institutions in the field of water resource management. The important challenge for the future in institutional research lies in going beyond the observation that institutions are important and in explaining instead how institutions actually affect management options and outcomes. It is possible to illuminate the relationships between institutional features and water management through comparative institutional research. This paper offers recommendations for studying water institutions in a comparative context, including methodological recommendations concerning approaches to comparative institutional research, and topics for comparative institutional research that appear especially fruitful at this time. The example of conjunctive management is used to illustrate the importance of institutional factors in water management, drawing to some extent on the authors’ recent experience with a comparative study of conjunctive management institutions.     

STATE WATER LAW REFORM: IDENTIFYING LEGAL AND MANAGERIAL ISSUES AND OPTIONS1

ABSTRACT: Statutory and case law at the state level provide critical legal frameworks for water management. As many state governments struggle to improve efficiency in water management and resolve conflicts over water usage, they must continually assess the efficacy of their state water law. Most states have water laws that are disconnected and overlapping. This article presents a methodology to assess state water law and take first steps toward a comprehensive state water resources act. The methodology is driven by issues and conflicts in water management. It synthesizes management and legal analyses into a process that incorporates the diverse perspectives of state water stakeholders. The results of the analysis are identification of management issues, profiles of state water law, and explorations of legal options that are available to the state government. Illinois is provided as a case study for this methodology.     

Addressing Declining Appropriations for Bureau of Reclamation Infrastructure: Policies Needed for Enabling Private Finance

Western water infrastructure was funded in the early and mid‐20th Century through federal financing through the Bureau of Reclamation. Over the past 30 years, federal financing has been less forthcoming, which has been commensurate with an increase in the need for financing rehabilitation and replacement of western irrigation infrastructure. As federal appropriations have declined, there has been increased interest in alternative approaches to infrastructure including public–private partnerships (P3s), loan guarantees, or title transfer of federal infrastructure. However, two of these approaches — P3s and loan guarantees — are precluded by existing federal budgetary policies, particularly Office of Management and Budget (OMB) scoring practices. If the OMB changed its policies for P3s or loan guarantees, private capital could play an important role in recapitalizing aging Reclamation infrastructure.