Thousands of dams threaten to collapse: they are too old and endanger nearby populations
The Mullaperiyar Dam in India has several major cracks. They were caused by the earthquakes of 1979 and 2011, and experts indicate that a future earthquake of 6.5 degrees on the Richter scale could cause it to completely collapse and the lives of three million people were threatened who live nearby.
The problem, as indicated in a United Nations study, affects tens of thousands of dams worldwide. Their life cycle is coming to an end, and they put the lives of all those millions of people who live near them at risk.
Dams on alert
Too many dams have reached or surpassed the barrier in which these constructions begin to be at risk. A period of 50 years is normally calculated as the life cycle of these facilitiesBut thousands around the world are well over that age and even approaching 100 years.
In the middle of the 20th century there was a clear fever to build large dams – China has 24,000 of them – but although there are plans in various countries to build new dams, the “revolution” that occurred at that time will not take place. The rate, which was “thousands of large dams” (those with a height greater than 15 meters) built per year, has been reduced to just a hundred a year.
In fact, the United Nations explains that “in 2050 the majority of humanity will live downstream of the great dams built in the s. XX“And these dams” are at increasing risk of failure. “Although there are no statistics that record failures, it is known that the rate of problems has grown significantly since 2005.
In Spain there are just over 1,000 large dams and their average age is 56 years old, and as in many other cases their purpose has been to supply water, irrigation, flood control and, of course, the hydroelectric power production, an option increasingly in the background before the advance of renewables like solar or wind power.
Many of those who manage those dams end up making the decision to dismantle those aging dams. This option is smaller than assuming repairs, but such operations can significantly affect the economy of low-income countries for which the destruction of these structures is more worrying.
Even so, dismantling is still a delicate process that has mainly been carried out in small dams: examples for large dams are rare, and the process, which is already long and complicated for small dams, is even more complex in the case of large facilities.
We have a recent example at the Glines Canyon Dam in Olympic Park, Washington, which after 87 years of operation was dismantled in 2014 after two decades of work.
Via | Yale