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Dam construction has been
for several decades an active industry, in both the industrialized
and the developing world. In northern industrialized countries,
such as Canada, the United States, Norway, Sweden, and the former
Soviet Union, dams have been developed as important sources of
hydroelectricity, as providers of irrigation water, or as instruments
of regional economic development. However, it is also recognized
that in most of these countries the era of building big dams
is over. With increasing costs, and growing opposition to such
projects, and the fact that most of the best sites for dams have
already been taken, the focus of dam construction has instead
shifted to the developing world.
Several colonial
powers were active dambuilders, with Great Britain in India perhaps
the most enthusiastic. In many countries, this activity has continued
after independence. For example, between 1949 and 1980, about
15% of India's total national expenditure was on the construction
of more than 1000 large dams and related infrastructure such
as irrigation canals. Dam builders have also been active in many
countries that do not have a recent colonial past. As many dams
have been built in China as in the entire rest of the world;
that country is also the site of the Three Gorges dam, now under
construction, and planned to be the world's largest dam. Latin
America has also been an active region for dam construction during
the last four decades.
Five of the largest and most
famous rivers in the world: the Nile, Amazon, Yangtze, Ganges,
and Zaire, face a range of environmental threats.
For more information on each river, click here.
Dams generate
a variety of impacts. The reshaping or redirecting of the flow
of a river and flooding of its valley has a variety of environmental
consequences. In many instances these projects also require the
displacement of the inhabitants of a region, or alter established
patterns of water or resource use, resulting in various social
impacts. Dams are also expensive projects; their construction
and operation has a range of economic implications for both the
immediate area and, often, the entire province or nation.
Environmental,
Social and Economic Impacts
Dams are more
than just concrete structures, and can generate more than just
electricity. They have also used to promote ideologies of national
pride and progress, and have served as symbols of national aspirations.
Dams therefore provide an entry into a variety of issues concerning
national economic and political development, such as concepts
and ideologies of development, the significance of international
aid, the role of civil society, and the significance of human
rights. As our experience with dams demonstrates, development
is never a politically or ideologically neutral process.
The development
of rivers has been intrinsic to numerous civilizations. As Fred
Pearce notes (see: Pearce, The Dammed, pp. 9-40) dams and canals
were the basis for extensive irrigation in several ancient societies
in which agricultural surpluses enabled the formation of complex
social organizations, as in ancient Mesopotamia, and along the
Nile in Egypt, the Indus in Pakistan and the Yellow River in
China. The importance of water development to these societies
led to their
controversial characterization by Karl Wittfogel as "hydraulic
civilisations" that had developed specifically in order
to organize the large labour forces necessary to create the canals
and other works. In the Middle East, the Roman world, Renaissance
Europe and elsewhere, water works have had a persistent importance,
as a basis for agricultural production, economic activity, and
the maintenance of state power.
Dams
and the Politics of Development
Dams have often
been the focus of intense debate, with different sectors and
interest groups expressing divergent attitudes towards these
projects. While some view them in terms of their role in national
economic development, others focus on their implications for
the immediate regions in which they are located. Some observers
emphasize the environmental implications of these projects, while
others draw attention to their economic or social aspects. This
diversity illustrates how different attitudes and perspectives
can generate very different views concerning the viability of
such projects.
Attitudes
Towards Dams
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