An Objective Analysis Of Hydropower Dams: They Are Outdated

Forbes

17-04-2025

According to the International Hydropower Association, people have been consciously using the power of water since at least the Han Dynasty, somewhere between 202 BCE and 9 AD. Water wheels powered trip hammers that were used for paper making, breaking ore, and to process grain. By the 1800s, various designs continued to improve upon each other, and by the 1880s people were generating electricity. It was an interesting and noteworthy progression in Victorian technology.
We don't need to keep using this outdated and dangerous method of power generation any longer. The Banqiao Dam Disaster of 1975, in China, was the single most devastating dam failure event, with at least 26,000 killed immediately and more than 200,000 people killed in total. The 1889 dam disaster that affected Johnstown, Pennsylvania was the largest civilian loss of American life until 9/11. The flood killed more than 2,200 steel workers and their families.
We don't need to live with these risks any longer. For electricity generation, better options exist. For flood mitigation and water retention, technology has evolved, and research now shows that the deforestation needed for hydropower construction directly worsens these problems. People commonly think that dams help water security but, in reality, dams directly cause deforestation which, in turn, destroys the source of water. Cutting down the forest inside the dam reservoirs is, in fact, jeopardizing electricity generation. The tropical rainforest and the 'flying rivers' they create are crucial for our climate to function correctly. The rainforests are not just a product of rainfall, but a source.
Projections show that likely rates of deforestation will decrease precipitation by 50% in the Congo, and about 40% in the Amazon. In the Cardamom rainforest, the presence of the dense canopy provides 3,500 to 4,000 mm of rain per year, the highest rainfall in the region. Studies of dams in Brazil show that deforestation caused by the dams reduce their potential for power generation by up to 10%, which while sounding modest, means for one plant, lost revenue of $21 million. This is representative of the trend.
Accumulated Losses in Energy Generation and Associated Revenue for Salto, Salto do Rio Verdinho, and ... More São Domingos HPPs, 2002-2022
Tree roots and fungi guide rainwater down to the water tables and create the headwaters for the rivers. Without these trees and their root system, the process of desertification will start to occur.
Nexus between Deforestation and Energy Generation Loss
Rainforests help a region stay supplied with water. This deforestation may seem like a local issue, but the costs are not felt only by the dam owners. While they will directly incur financial losses, we will all suffer from the growing water insecurity. We need to stop deforestation. Dams cause deforestation, and destroy a region's natural water cycle. People think dams contribute to water security but, in fact, make the situation worse. Evaluations conducted over the last 30 years disprove the old notions that building a big pool of water will keep the water in reserve. We now know that it is much more complicated than that. What seems to be only a local issue, in fact has global consequences. Trees regulate the rain and water supply and have a huge impact on global air currents, thus modifying rainfall patterns across the entire globe. For example, there's a direct link between deforestation in the Amazon and the reduction of rainfall in the United States, and deforestation of the Congo Basin has a direct impact on reduction of rainfall in Europe (Duke research).
Impact of projected future forest loss on annual mean precipitation
For electricity generation, water security, or for financial returns, dams are a bad investment. For short-term gain or long-term security, dams will cost more than they provide. Any person, corporation, or society that wants to build a large hydropower project would do better to compare and consider other options.