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[1]
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
[1] 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.