Making Decisions on Dams
Dam Removal: Science and Decision Making. Heinz Center Panel on Economic, Environmental, and Social Outcomes of Dam Removal, Heinz Center for Science, Economics, and the Environment, Washington, DC, 2002. 221 pp., free (ISBN 0971759219 paper).
This important and timely book provides the first comprehensive treatment of dam removal. It brings together disparate fields relevant to understanding environmental and other issues surrounding dam removal, and it shows how decisions and policies must depend on input from all these disciplines.
The Heinz Center, a nonprofit institution that seeks to improve the scientific and economic foundation for nonpartisan environmental policy, convened a diverse group of experts to study the economic, environmental and social outcomes of dam removal. The authors included specialists in geography, aquatic ecosystems management, economics, environmental law, engineering, federal and state administration, environmental consulting, dam safety, hydropower, and hydraulic engineering. The authors' goals for the report were to (a) outline the wide-ranging outcomes of dam removal, including potential positive and negative effects, and list issues to be addressed in the decisionmaking process; (b) define indicators for measuring and monitoring environmental, economic, and social factors related to dam management or removal; and (c) provide available information sources for decisionmakers. The target audience was policymakers, interest groups, private citizens, and personnel in local, state, and federal agencies, as well as scientists interested in defining future research needs.
To a large extent, those goals are realized. The book is successful in covering the wide range of topics relevant to dams and their removal. Because of the infancy of the field, the authors stress the need for adopting an adaptive management framework in which lessons learned from past and current dam removals, as well as from those under consideration, are translated into modifications of research, policy, and practice for future removals and decisions. They provide explicit recommendations at the end of each chapter and in the summary to support this adaptive management approach. When their recommendations are specific, they are effective in conveying the critical issues that must be addressed in terms of science and policy. The book is thorough in its presentation of potential data and information sources, and it gives the Web sites for as much of that information as possible. The writing is clear and at an appropriate level for the target audience, explaining concepts without excessive jargon.
The book begins with a careful review of the history of dams in the United States, a plethora of dam statistics, an introduction to dam removal as a salient issue, and summary information on the current status of removals. The summary statistics illustrate the immense scale of the problem of aging US dams, as well as the wide range of sizes and types of dams that must be taken into consideration. Indeed, the summary statistics alone guarantee that this report will be cited extensively in future publications. The authors make a clear case in this section for the importance of small dams as the focus of the report, because of their sheer number and because they are the most common targets for current and planned removals.
Two chapters cover the environmental aspects of dam removal, focusing primarily on physical and biological aspects. Owing to the paucity of data and published studies on actual removals, both chapters present primarily information on the environmental impacts of dam construction and operation and use this to speculate on whether removal will reverse these impacts. The general prognosis is that dam removal will reverse most of the adverse impacts of construction, although the authors acknowledge the uncertainty inherent in predictions based on limited data. The potential negative impacts of removal are also covered briefly. Potential problems caused by contaminated sediments in reservoirs and possible impacts on water quality are mentioned in both chapters, but, unfortunately, those problems are not discussed in any detail.
Three other chapters cover the legal, economic, and social aspects of dam removal. A discussion of federal laws that are likely to have significance for dam removal introduces the legal aspects of the issue. Readers will gain an appreciation of the wide array of laws related to river management and how these influence dam removal decisions. The economic context provides an interesting twist. The authors argue that formal cost-benefit analysis, which has traditionally been used for water resource–related decisions like dam construction, does not necessarily apply to dam removal, because it is difficult to define a reference case for the analysis—in the case of a deteriorating, unsafe dam, “no action,” the traditional reference case, may not be an option—and because we are unable to confidently predict the environmental impacts of dam removal. The authors describe how this unique attribute of the topic, and others, will affect the economic aspects of decisionmaking. Finally, because of their historical and perceived aesthetic value, dams play a unique role for local communities, and the authors describe how those perceptions of dams and rivers factor into dam removal decisions.
The chapter on dam removal decisions is a particularly valuable contribution, in that it outlines specific steps that decisionmakers ought to take in considering a dam for removal. These steps range from initial goal definition to data collection for monitoring studies. In particular, the authors stress realistic goals and the importance of short- and long-term monitoring, and even propose to develop a handbook that would provide detailed guidance on site evaluation for communities considering dam removal. This chapter might best be viewed as the closing chapter for the book; using the other chapters as background, it provides the framework for actual decisionmaking.
As with all works of this size and diversity, there are shortcomings, two of which struck us as particularly important. First, the chapter focusing on legal issues examines only federal laws, yet the focus of the report is intended to be on small dams, which are governed primarily by state and local laws. Although coverage of the legal context in all states would have been beyond the scope of the book, the lack of some state-level coverage leaves local decisionmakers without necessary guidance. Discussion of at least one set of state-specific rules related to dam removal would have been useful, given the targeted audience, and should be considered for follow-up work by the Heinz Center Panel. Second, while there are indeed few peer-reviewed publications about dam removal, the authors have neglected to mention several of those that are available. These include papers on state and federal legal issues (Martini 1998, Bryant 1999), economics (Loomis 1996), geomorphology (Wohl and Cenderelli 2000), and biology (Kanehl et al. 1997, Kareiva et al. 2000).
Despite its shortcomings, the Heinz Center report offers a substantial overview of a critical topic and thus constitutes an important contribution to the continuing debate surrounding dam removal. Numerous studies of dam removal are under way, as evidenced by journal articles like the ones in this issue of BioScience. This report is the current benchmark for the state of environmental, social, and economic knowledge that can support decisionmaking. Finally, the cost—free—makes this book hard to beat.
- 1BC Bryant. 1999. FERC's dam decommissioning authority under the Federal Power Act. Washington Law Review. 74: 95-125.
- 2PD Kanehl, J Lyons, JE Nelson. 1997. Changes in the habitat and fish community of the Milwaukee River, Wisconsin, following removal of the Woolen Mills Dam. North American Journal of Fisheries Management. 17: 387-400.
- 3P Kareiva, M Marvier, M McClure. 2000. Recovery and management options for spring/summer Chinook salmon in the Columbia River basin. Science. 290: 977-979.
- 4JB Loomis. 1996. Measuring the economic benefits of removing dams and restoring the Elwha River: Results of a contingent valuation survey. Water Resources Research. 32: 441-447.
- 5EC Martini. 1998. Wisconsin's Milldam Act: Drawing new lessons from an old law. Wisconsin Law Review. 5: 1305-1336.
- 6EE Wohl, DA Cenderelli. 2000. Sediment deposition and transport patterns following a reservoir sediment release. Water Resources Research. 36: 319-333.