UN Report on Ageing Dams

The United Nations has recently released a report stating that the world has ageing dams and by 2050 most of the people on the Earth will live downstream of tens of thousands of dams built in the 20th century.

Key Points

  • The United Nations has released a report titled ‘Ageing water infrastructure: An emerging global risk’.
  • The report has been compiled by the United Nations University Institute for Water, Environment, and Health (UNU-INWEH).
  • As per the report, there are 58,700 large dams across the world, and most of them were built between 1930 and 1970 with a design life of 50 to 100 years.
  • More than 1000 large dams in India will be around 50-years-old in the year 2025.
  • The world has similar aging structures and these are posing a growing threat.
  • This ageing of dams will result in an increase in cases like loss of a dam’s functionality and effectiveness, dam failures, increased dam repair and maintenance costs, increasing reservoir sedimentation, etc.
  • The analysis also included dam ageing case studies from India, France, the U.S., Canada, Japan, Zimbabwe, and Zambia.
  • As per the report, 55% of the world’s total large dams i.e. 32,716 large dams are found in just four Asian countries: India, China, South Korea, and Japan. Most of these dams will be above the 50-year threshold soon.
  • As per the report, the problem of dam ageing is confronted by 25 nations as 93% of large dams are located in these countries only.

Dam Ageing in India

More than 1,115 large dams in India will reach near the age of 50-years in the year 2025; over 4,250 large dams in the country will be above 50-years in the year 2050 while 64 large dams will be more than 150-years-old in the year 2050.

If the Mullaperiyar dam in Kerala, India which was built over 100 years ago, fails, around 3.5 million people will be at risk.

Dam Ageing in the United States

As per the report, many well-designed and maintained dams in the US can easily reach 100 years but the phenomenon of “decommissioning” will increase. The average age of 90,580 dams in the US is 56 years. Over 85% of dams in the country in 2020 were operating at or beyond their life expectancy. Also, 75% of dam failures in the US occurred after 50 years of age.