On this deceptively blue planet, fresh water is in short supply. Today on World Water Day (March 22) we are all concerned about worsening water scarcity brought on by wasteful habits, population growth, and increasing urbanization. To this equation we must add the uncertainties of global climate change.
Recent disastrous floods following years of drought in my home region of southern Africa have shown that water isn't always where we want it, when we want it. So dam technology was developed to manage water resources to serve human needs.
But dams have become increasingly controversial.
For the better part of the last century, it was presumed dams delivered development, be it through irrigation, flood control, hydroelectricity, or ensuring urban water supply. Annually, $50 billion is spent designing and building dams. Because most rivers that could be dammed in northern countries have already been dammed, attention has shifted to southern, less developed regions.
Many governments in Africa, Asia, and Latin America would like to build more dams. They want to develop their rivers for water and food security, to control devastating floods, and for hydropower which has proven a development boon in so many countries. But they can't get the funding for those dams, because in recent years international lending agencies have shied away from hydroelectric dams. They seem too expensive. It's far cheaper to build a gas-fired electric plant than a hydropower dam, even though the former means importing energy supplies that create greenhouse gases.
But, an even greater deterrent to dams is the cost of controversy.
In recent years non-governmental organizations (NGOs) have launched many successful campaigns against large dams because those projects can have devastating impacts on communities, flora, and fauna. Most controversial of all is that dam construction annually requires the displacement of an estimated 4 million people, disproportionately affecting indigenous people.
The debate over whether dams are good or bad has become one of the most intensely contested issues in sustainable development today. And the pendulum has swung away from dams: The number constructed annually has fallen from an average of 450 per year between 1975-90, to 300 in the 1990s.
Regardless, dams remain a viable choice in delivering an array of development benefits. But they're neither a blanket solution to development needs nor the unmitigated disaster their critics claim. The question is: How does a society determine its best choice in managing water resources to meet growing demand in a sustainable manner?
The World Commission on Dams (WCD), which I chair, was created in 1997 to inform that decision-making process and break the deadlock between pro- and anti-dam lobbies. The independent commission was formed by the IUCN-World Conservation Union, a coalition of more than 800 environmental agencies and NGOs, and the World Bank. Members are 12 eminent representatives from government, NGOs, academia, and international business. The commission is conducting the first independent, global review of the costs and benefits of dams, and will develop criteria for future decision-making on dams.
Making such decisions has never been more difficult. Let's take as an example concerns about global warming and the role dams could play in alleviating - or worsening - the situation.
The current energy dilemma in Norway illustrates the local, regional, and global concerns about dams and their alternatives in the context of climate change.
Thanks to its vast network of rivers, Norway, 15 years ago, was almost completely dependent on hydropower for electricity. But concerns for the environment and indigenous peoples led to a moratorium on dam construction. Consequently, to meet increasing energy demand, Norway imported electricity from Danish coal-burning power plants.
Since then, Norway has decided to reduce its contribution to the "greenhouse effect" of global warming caused mainly by burning fossil fuels - coal, oil, and natural gas. There is a proposal to build natural-gas power plants in Norway: They would emit greenhouse gases, but at a lower rate than Denmark's coal plants.
However, the Norwegian environmental movement did not accept this "lesser evil" argument, and the pro-environment Prime Minister Kjell Magne Bondevik resigned this month over the issue - probably the first government to fall over global warming. Interestingly, there has been little discussion in Norway of building dams in place of those fossil-fuel plants.
At first glance, dams would appear to be the emissions-free choice. But there are no perfect, painless solutions. Scientists gathered at a WCD workshop in Montreal last month agreed that dam reservoirs also emit greenhouse gases due to the decomposition of trees and other biomass in reservoir waters.
Research indicates hydropower reservoirs in northern countries generally produce less greenhouse gas than fossil-fuel plants of similar capacity. Yet the opposite is true for certain dams studied in tropical regions. Research in this area is still inconclusive, but rapidly expanding, thanks to collaboration between the two sides on the dams debate.
Weighing the costs and benefits of various options in water and power development is a difficult task to be undertaken by societies as a whole, not just by governments, NGOs, or the private sector alone.
The WCD final report, due in November, will provide the tools societies need to determine their best options - dams or otherwise - in delivering the greatest benefit at the least cost so that our precious water resources are shared equitably, sustainably, for centuries to come.
*Kader Asmal, South Africa's minister of water affairs and forestry under Nelson Mandela, and now education minister, chairs the World Commission on Dams. He is the winner of the 2000 Stockholm Water Prize.
(c) Copyright 2000. The Christian Science Publishing Society