Fatalities from structural collapses are not the only cause for concern with dams. It’s time to consider a moratorium on constructing hydroelectric dams, which are destructive everywhere. Dams disrupt ecosystems. They block fish migration and can separate spawning habitats from rearing habitats. Still water in a dam’s reservoir is a profoundly different environment than flowing water to which species have adapted over millennia.
Dams drive people out of their homes. The New Deal’s Hoover Dam took reservation land from Yuma Indians in 1933. In Mexico, the construction of 4,000 dams involved the removal of 185,000 people, and dams have pushed an estimated 80 million people out of their homes worldwide.
An estimated 400 million to 800 million people in the world who live downstream from dams lose access to clean water, are poisoned by industrial development, and watch resources shrink. Those living in tropical areas can experience an increase in diseases such as malaria, yellow fever and dengue.
Dams have provoked violence in many countries, including Burma, China, Colombia, Ethiopia, Guatemala and Sudan. In 1982, 440 indigenous people were killed to make way for Guatemala’s Chixoy Dam construction.
Rivers cross international borders of 145 countries. When a river runs through multiple countries, there is a potential conflict over building a dam. Since 1975, Turkish dams have reduced the flow of water to Syria by 40% and to Iraq by 80%.
It would be a tragic irony if dams were used to combat climate change because they produce greenhouse gases. Construction requires massive quantities of concrete, which itself requires heat for production. Each ton manufactured releases one ton of carbon dioxide into the atmosphere.
Organic matter rots in dam reservoirs and produces the potent greenhouse house gas methane. This methane is estimated to account for 4% of all human-made climate change, equivalent to that of aviation.
Construction of dams has cost $2 trillion since 1950. A small country whose energy comes mainly from hydropower can find that the average cost overrun of 96% leaves it highly indebted to international lenders. Governments often complain that financial problems prevent proper attention.
Unlike the extinction they cause, dams are not forever. Silt eventually interferes with functioning, and turbines malfunction, cracks occur and design flaws appear. The financial and human cost of dam breakage is often vastly understated. Though the U.S. has had plenty of dam disasters, the worst was in China.
The Banqiao Dam was completed in 1952 in Henan province. This was despite scientific warnings against such unwise decisions as building more dams in an earthquake-prone zone already fraught with landslides.
On Aug. 15, 1975, a typhoon collided with a cold front, and in less than 24 hours the area received more rain than it did in a typical year. The Banqiao collapse sent a 31-mile-per-hour tidal wave down the river, knocking out 62 additional dams. Entire villages were swept away. Roads were washed out, and rescue communication was non-functional. When rescue teams finally arrived, they found that hunger was joined by disease and summer heat.
For every person who died after the initial collapse, five more died from disease. The total estimated death count was 171,000.
Perhaps the greatest tragedy of the Banqiao is that dynamics for economic growth, which were the foundations for disaster, continue to flourish across the globe. Scientific recommendations are still ignored, and more industrial plants full of toxic chemicals are located next to rivers. Climate crisis means that weather events that cause dam collapses are becoming more frequent and more extreme, and governments continue to build multiple dams on the same river.
What would happen if the need to provide energy while eliminating fossil fuels cannot be accomplished by solar and wind power? Since hydropower produces more electricity than these two combined, it is next in line.
But there is an option: energy conservation. It includes using vastly less energy by having compact communities that require less transportation, smaller home spaces that need less heating and cooling, less production of energy-absorbing gadgets designed to fall apart, and a shorter work week via manufacturing fewer unneeded products.
Don Fitz, Ph.D, has taught Environmental Psychology at Washington University and Fontbonne University.