Buckley, Patrick. 2003."Review of 'Silenced Rivers: The Ecology and Politics of Large Dams'. Patrick McCully. London: Zed Books, Limited; New York: St. Martin's Press, 2001. Professional Geographer. Vol. 55, No. 2. p. 285
Silenced Rivers: The Ecology and Politics of Large Dams. Patrick McCully. London: Zed Books, Limited; New York: St. Martin's Press, 2001. ill and 416 pp. , diagrams., notes, appendices, and index. $69.95 cloth ( ISBN 1856499014), $25.00 paper (ISBN 1856499022).
Engrossing, thought provoking, troubling; McCully's well documented and carefully researched study of large and major dams concludes that their era much like fossil fuels is drawing to a close. The main theses of this study are two. First, large dams as a whole have not provided an adequate economic or social return on their substantial investments ($2 trillion), especially in developing countries where the money could be better invested elsewhere. Second, long-term, independent, post-construction, comprehensive benefit/cost studies of large dams are rare to non-existent. Instead there is an industry-wide trend to over-state benefits and under-state or even ignore costs, and terminate all investigation shortly after the last bucket of concrete is poured. Time and again even the most basic hydrologic data, a critical input for efficient dam design and operation, is badly flawed due to either an actual absence of reliable long-term data, or unjustifiably optimistic projections.
As a result, in recent years, as public sector subsidies for dam construction have contracted, more calculating, risk conscious private capital has failed to fill the void. Thus, current mega-dam construction like the Sardas Sarovar in India or the Three Gorges in China represent dinosaurs from a bygone era still stumbling ahead under the relentless prodding of a down-sized industry and contracting group of government supporters unwilling or unable to comprehend the changes at hand.
Central to McCully’s arguments are an extensive and careful critique of the four major justifications for large dams: hydro-power, irrigation, flood control, and drinking water supply. In these areas he finds that time and again promised benefits have rarely equaled projections and occasionally failed entirely. Even the industry itself no longer bills hydro as a cheap energy source. Siltation plus long-term maintenance, refurbishing, and dismantling costs even under the best of circumstances makes hydro-power look less like long-term sustainable technology and more like a temporary bridge technology. Environmentally hydro has never been considered entirely benign, but recent studies indicate that dams in the tropics could produce much greater quantities of greenhouse gases than even conventional fossil fuel plants (in some extreme instances dams are projected to produce 2 to 20 times more CO2 than coal burning plants). This further suggests that even hydro's use as a bridge technology has strong geographic limitations.
A careful review of large dam irrigation projects calls into question the thesis that their scale economies provide greater efficiencies. Instead, these projects are littered with examples that never lived-up to their projections, are rife with corruption, and have all too often alienated, and even impoverished the very populace that they were slated to serve through displacement, and denial of access to and participation in managing their resources. Further, the contribution of large dam irrigation schemes to the over-all increase in food grain production in developing countries may be rather modest. In the case of India it is pegged at as little as 10% despite the fact that India has quadrupled food grain production since independence while pouring more development money into large dam irrigation schemes then any other sector of agricultural development.
In a word flood control is returning to flood management as the vagaries and needs of nature become better understood and the realization sinks in that the bigger the dam the greater the damage when the flood finally comes. Finally, since water supply has generally played only a minor role in large dam construction, it rarely has provided an adequate justification for such projects.
For researchers, this book is an excellent handbook and overview to anyone with an interest in dams. Its organization is quite comprehensive providing dedicated chapters on the history of dams; impact of resettlement; and the rarely discussed issues of the aging, technical failure, and especially decommissioning of dams. In addition, whole chapters deal with environmental consequences of dams; irrigation and the poor track record of large dams in this arena; the anti-dam movement; and a new introduction in this updated edition details the findings of the World Commission on Dams (WCD) 2000 report. The WCD, a broad based group including representatives from industry, governments, and NGOs, was sponsored by the World Bank with the charge to investigate the impact of current policies. On the whole it validated McCully's criticisms and set about laying-out a new set of criteria for planning any future large dams.
Finally, it should be noted that this text is organized in a very inviting and attractive manner for use in by students in intermediate or advanced courses focusing on sustainable development. Each chapter is structured in such a fashion as to provide a complete and in depth analysis of the issue at hand, enabling students to dive right into the subject and thus can be used in a stand alone fashion while providing excellent references for a more complete regional analysis. For example, chapter 6 which focuses on irrigation, would provide excellent background reading in a course on South Asia (one of the most heavily irrigated regions of the world) or world food and population issues (one-third of the global harvest is dependent on irrigation). It provides an outstanding introduction to the physical processes of irrigation, its long-term impacts, and reviews the social, economic, and political consequences of past large scale operations. It provides compelling evidence that small-scale, locally controlled irrigation schemes have provided far greater long-term benefits to local populaces than large behemoths favored by central governments, thus raising interesting issues of the dynamic tension between the core and periphery. In an advanced seminar class, this book could provide a framework around which careful regional analysis could be used to critique McCully's theses. The extensive references provide a trove of materials for independent work by students.
The weakness of this book is that it leaps from one project to another (without any maps!) at a breathtaking speed, selectively finding worst case examples for each shortcoming. One can easily be overwhelmed by too many unfamiliar names and places without any appreciation for the regional social and economic environment within which they exist. However, the detailed references provide the interested reader with tools necessary to begin a more comprehensive investigation of a specific dam.
On the whole this is an important contribution to understanding the global and regional difficulties in creating a sustainable economy in this century.
Key Words: dam, hydroelectricity, irrigation, sustainable development, anti-dam movement
 A large dam is usually 15 meters or more from foundation to crest, or 10 to 15 meters with either a reservoir of 1 million cubic meters or a crest length of 500 meters. A major dam has a minimum of at least 150 meters in height, a volume of 15 million cubic meters, a reservoir of 25 cubic kilometers, or 1 gigawatt of generation capacity. Both are based on the International Commission of Large Dams definition.