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Mega-dams: A solution or a problem?


Le Grand Portage | CC BY 2.0

Paul De Maeyer - published on 07/13/18

On the one hand they are clean energy sources, but on the other hand they can have a negative impacts at the social, cultural and environmental levels.

In this increasingly energy-dependent world, the energy obtained from water has ancient roots. The water mill mechanism was described by Marcus Vitruvius Pollio (c. 80 BC – after 15 BC) in his treatise De architectura.

Regarding the current situation, it is estimated that more than half of the energy produced in South America is generated from hydropower. In some countries of the world, like Costa Rica and Norway, hydroelectricity amounts to near 100 percent of total production.

Even though the hydroelectric water energy does not pollute as such, and often prevents the producing countries from having to import expensive, polluting and non-renewable energy sources, it has indeed a less positive side. It is necessary to build hydropower plants in order to transform a stream of water into energy.

Conventional hydropower stations consist of a dam crossing a river gorge. The bigger the dam and the reservoir created by it, the greater the energy production. But also the larger the size of the dam, the larger its environmental and social impact will be.

The Three Gorges Dam in China

The largest dam ever built, the Three Gorges Dam, spans the Blue River in Hubei province, in central-eastern China. The Yangtze, as the Blue River is also known, is the longest watercourse in Asia and also the third longest river in the world, after the Amazon in South America and the Nile in Africa.

The reservoir of the enormous dam (185 meters high and over 2.3 kilometers long) is about 600 kilometers long and contains around 22 billion cubic meters of water, though it has a maximum capacity of 39 billion cubic meters.

The objective of the controversial dam, whose construction was approved in 1992 by the National People’s Congress with a record number of abstentions, was not only the generation of clean energy, but also to make the river traffic safer and have a better control of the rising Yangtze.

A positive aspect of this gigantic dam, which started producing energy in 2006 (the last of 32 total turbines were activated in 2012), is certainly the fact that it avoids the combustion of 31 million tons of coal every year, which would have released 100 million tons of greenhouse gas per year, as noted by Il Corriere della Sera.

On the other hand, the social, cultural and environmental impact of the Three Gorges Dam is negative. For example, not only were the authorities forced to “relocate” more than 1.3 million citizens, but the waters of the reservoir have erased 1,300 archaeological and historical sites, and completely or partially submerged 13 cities, 140 towns and 1,352 villages.

The colossal hydroelectric complex also entails geological risks. Not only is the dam built on a seismic fault, but some experts, including Matt Ridley, who wrote an article on the subject in the Wall Street Journal, believe that the huge mass of water collected in the reservoir might actually be able to induce seismic phenomena.

In an interview published on the Chinadialogue website, geologist Yang Yong, director of the Hengduan Mountain Research Institute, linked the earthquake that in August 2014 caused over 600 deaths in the province of Yunnan with the dam system of the Jinsha river, a main tributary of the upper Yangtze.

Hydroelectric projects in Ethiopia

In order to stimulate economic development, Ethiopia has also started major projects to generate hydraulic energy. Addis Ababa is building a chain of hydroelectric plants on the Omo River in the southwest of the country. It is composed of five dams, of which the Gibe I, Gibe II and Gibe III plants are already operational, while Gibe IV and Gibe V are still in the planning stage.

Also in this case, concerns about socio-environmental impact cast shadows over the whole project. For the construction of the first plant, Gilgel Gibe I, 100,000 people had to be relocated, and the entire project threatens several farming populations who live along the river. The project could also involve a lowering of the water level of Lake Turkana, located on the border with Kenya, as various NGOs including Survival International have warned.

Gibe III, built by the Italian industrial group Salini Impregilo and inaugurated in 2016, is — with a height of 243 meters and a reservoir of 14 billion cubic maters — the largest dam on the African continent, though it will be soon overtaken by another pharaonic project of Addis Ababa: the Grand Ethiopian Renaissance Dam.

The greatest problem related to this hydroelectric giant (also built by the Italian multinational Salini Impregilo) is international in nature. The dam in question will be built on the Blue Nile. This joins with the White Nile in Khartoum, Sudan, and is directly responsible for the annual rises of the Nile, of crucial importance for Egypt.

At the inauguration of the works in 2013, the then-president of Egypt Mohammed Morsi used very clear words. “If only one drop of the Nile is lost, our blood will be the alternative. We are not warmongers, but we will never allow anyone to threaten our security,” said Morsi.

On June 10, Ethiopian Prime Minister Abiy Ahmed Ali met in Cairo with the current Egyptian president Abd al-Fattah al-Sisi to reassure the Egyptian authorities and to ward off the specter of a possible water war.

“We will take care of the Nile, we will preserve your share of the Nile’s waters, and we will work to increase this share,” promised Abiy, who took office on April 2. Ethiopia wants to benefit from the river, but without harming the Egyptian people, declared the first Ethiopian premier from the Oromo people, quoted on the English page of Deutsche Welle.

As Franco Nofori explains on the African Express website, once the work is completed, it will take no less than three years to fill the dam’s reservoir. It is hoped, therefore, that Addis Ababa will be able to maintain the flow of the Blue Nile during all that time.

The Hidroituango project in Colombia

Despite their enormous size, large dams sometimes seem giants “with feet of clay” (cf. Book of Daniel, 2:31-35). This is demonstrated by the alarms sounded last May in Colombia, in response to very serious problems with the Ituango dam, still under construction, on the Cauca river, one of the most important in that South American country.

As the BBC Mundo website explained in May, a number of landslides after strong and persistent rains in the region set off alarms and caused the evacuation of 5,000 inhabitants in the area, as well as the blocking of the only diversion tunnel still in function of the three that were initially built.

Facing the risk of overflowing and a possible collapse of the dam, the engineers of the company Empresas Públicas de Medellín (EPM) had no choice but to flood the machine room. Although another 25,000 campesinos have been evacuated as a precautionary measure, the situation now seems now to be stabilizing, as reported by Colombian Caritas, which assists the displaced.

If the Hidroituango project is completed, not only will an increasingly threatened natural habitat disappear underwater, but numerous mass graves of desaparecidos killed by right-wing paramilitaries of the Autodefensas Unidas de Colombia (AUC) during the civil war will be inundated, too — so warn the authors of an article published on the website. “The thesis – so they argue – that hydroelectric plants are a source of ‘clean energy’ compared to those based on fossil energy is false.”

According to the ecotheologist Alirio Cáceres Aguirre, professor and researcher at the Faculty of Theology of the Pontifical Universidad Javeriana in Bogotá, the dam should not have been built be at all. The area chosen for the project “is characterized by a friable mountain range, at that point the river runs through a canyon and landslides are frequent, there were no security conditions to build a work of this type,” explains the deacon of the Bogotá archdiocese.

For Cáceres Aguirre, this is a “pharaonic megaproject” that “denotes a culture of domination over nature, that same culture that was denounced by Pope Francis in his encyclical Laudato Si’. It has followed a purely technocratic paradigm, believing that problems would be easy to solve.”

This short overview confirms how large-scale infrastructure projects can influence and impact on the environment and the surrounding people. It is worth recalling a sentence attributed to one of the fathers of quantum mechanics, Werner Heisenberg (1901-1976): “When a child throws his doll out of the cradle, Sirius wobbles,” he said, indicating in this way that every human action has always, in one way or another, a universal impact.

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