Less than one percent of water on Earth is found as fresh water in lakes and rivers. This water is vital to all land-living creatures. The world’s rivers have forever been a source of life in continental areas. They have been the cradles of early civilizations, supporting the development of human communities, fertilizing lands for agriculture, and providing routes for trade and shipping. The progress of mankind was accompanied by a constant growth in water demands; consumption has multiplied more than thirty times during the past three centuries, and nowadays it still increases by two to three percent every year. Moreover, in the last decades, dam building, global warming, and pollution have seriously endangered our rivers.
As a result of damming and drought, the delta of the great Colorado River, once hosting some 400 species of plants and animals, has turned into a huge salt desert with loads of clamshells. The Rio Grande is currently split in two, as it virtually disappears on some 200 miles of its course, called by local people “the forgotten river”. The famous slit-carrier Yellow River of China is hardly reaching the sea today because of intensive damming and drying out of its sources, the Tibetan glaciers. The Aswan High Dam, designed 40 years ago to prevent the recurring floods and droughts of the Nile, has reduced the flow rate of this world’s probably longest river to only six percent of its previous level. Similarly, the Indus in Pakistan, Australia’s Murray River, and Germany’s River Elbe have run dramatically dry. The Amazon was affected by terrible drought a few years ago, but it is still largely devoid of dams. Salmons are endangered in Alaska’s Yukon River because its waters are getting too warm. The water removed for irrigation from Central Asian rivers has shrunk the Aral Sea down to 20 percent of its volume in the past half a century. Because of global warming, the snow sources of the great rivers of the American west are expected to gradually decrease in the future decades. Examples may continue.
In 2006, the UN World Water Development Report pointed out that “we have hugely changed the natural order of rivers worldwide”, seeing that “more than one half of the world’s 500 major rivers are being seriously depleted and polluted”. The reason is that “humanity has embarked on a huge ecological engineering project with little or no preconception of the consequences.”
Starting with the Colorado Hoover Dam some 70 years ago, people worldwide have built, on average, two giant dams a day. Some 50,000 dams are now trapping fifteen per cent of all the flowing water in the rivers. No doubt, dams and reservoirs have immensely contributed to our development, in many ways; they ensure water supply for domestic and industrial needs, farming irrigation, flood control, hydro-power, continental navigation, and recreation. On the other hand, the world’s large dams have also brought disastrous ecological effects, by causing loss of species, flooding of lands and forests, and displacing human populations. “We have used our engineering skills to harness the Earth’s water systems (and) now we are paying the price” Geoffrey Lean once wrote for “The Independent UK”. Dams disturb river ecosystems, disconnecting downstream from upstream species, impeding migrations, and isolating the river from its floodplain. As a result, wetlands are drying, and many of the world’s freshwater fish species are totally or nearly extinct.
Nevertheless, during the past decades, the world has become increasingly aware of the importance of preserving its natural environment. In 1972, the UN “Declaration on the Environment” and the Club of Rome’s memo on the “Limits to Growth” have indeed changed our views on ecology. In 1997, the UN’s Brundtland Report on “Our Common Future” launched the concept of “sustainable development”, which was incorporated a few years later by the UN Conference on Environment and Development (UNCED) into a universal action program.
The 2006 UN Report stated that no big dams should be ever built on the rivers that have so far escaped them, and that dams should be removed anywhere they are thought to be detrimental rather than useful. As a matter of fact, the yearly rate of dam building has constantly decreased worldwide for the past 30 years, from almost 900 to about 100, and it is still expected to decline in the years to come. In the USA, some 500 large dams have been broken down, mostly for ecological reasons. Instead, focus is placed on smaller-scale dam projects.
Environment preservation is now a major concern of all professionals dealing with water resources. The International Commission on Large Dams (ICOLD), a non-governmental international organization founded in 1928, has played an important role in recent years in designing, promoting, and implementing safety concepts in dam engineering. System planning, public consultation to obtain consensus, identification of environmental impacts, economic analysis, monitoring, and research, are all generously supported by ICOLD experts to help management of projects and of existent dams and reservoirs.
Political and social opposition are important means of preventing large dam constructions, prone to induce massive population resettlements. Opposition not only can succeed in causing building delays, but it can also use threats of boycott or adverse publicity against investors. Great victories of the opposition were witnessed in the cases of Sardar Sarovar dam project in India and the Rasi Salai Dam in Thailand. In 1987, the Swedish parliament banned dam building on most of the country’s dam-free rivers, whereas in 1989 enormous public hostility compelled the Hungarian parliament to abandon Nagymaros Dam and put off works on Gabcikovo Dam. Very recently, on the 14th of April, the International Day of Action for Rivers, was marked by several anti-damming public protests in countries like Canada, South Africa, Germany, and Chile.
The “International Rivers Network” (IRN) assumes the mission “to protect rivers and defend the rights of communities that depend on them”. With organizations in over 60 countries, IRN is today one of the most important actors in encouraging social movements, reforming decision-making processes, opposing harmful projects, demanding for reparations and for dismantling of existent unsafe dams, raising awareness through publications, and promoting alternative solutions. The rate of large dam building has fallen by half since the creation of IRN.
Backed by the World Bank, the independent World Commission on Dams (WCD) was founded in 1998 to analyze the economic effectiveness of dams, and to develop standards and guidelines for dam building. The WCD concluded that while “dams have made an important and significant contribution to human development,” in “too many cases an unacceptable and often unnecessary price has been paid to secure those benefits, especially in social and environmental terms, by people displaced, by communities downstream, by taxpayers and by the natural environment.” The WCD set of 26 guidelines has become a point of reference in international dam building industry. Several governments, including Germany, South Africa, Sweden and Vietnam are set to include WCD recommendations into national policy. Also, the World Bank and the International Hydro-power Association strongly promote these recommendations.
As Patrick McCully wrote in 2005, the “large dam era” is expected to decline, as buildings will probably stop completely in the next decade. The world’s energy future requirements will not be ensured by hydro-power, but most probably by the development of renewable energy technologies, like solar, wind, geothermal, biomass, and wave power. Flood effects can be minimized by improving warning and evacuation systems, whereas drought can be neutralized through better exploitation of groundwater. In Western countries, water demand has been dramatically reduced due to advances in public water supply systems, irrigation and home appliances. Desalination of seawater, harvesting of rainwater, and water recycling may also provide solutions during drought episodes.
This may seem like an overly optimistic scenario, but it only depends on political decisions to make it work. And political decisions can and must be influenced by ordinary people. Taking actions, like monitoring local water management, reducing home energy consumption and water use, rain harvesting and helping groundwater recovery, fighting against dams and polluting industries, promoting public awareness, supporting conventional energy efficiency and use of renewable energies, reducing global warming by less driving and flying, all of these can help protect our rivers and riverine ecosystems. Saving the rivers is in the power of our own hands.