These countries have the most 'alert age' dams. Here's what it means 

A helicopter drops sand bags on top of the dam after a nearby reservoir was damaged by flooding

Older dams are more vulnerable. Image: REUTERS/Phil Noble

Katharina Buchholz
Data Journalist, Statista
Share:
The Big Picture
Explore and monitor how Fresh Water is affecting economies, industries and global issues
A hand holding a looking glass by a lake
Crowdsource Innovation
Get involved with our crowdsourced digital platform to deliver impact at scale
Stay up to date:

Fresh Water

  • Once a large dam becomes 50-years-old, it reaches 'alert' age, whereby its upkeep becomes harder, and they become more dangerous.
  • A new report by the U.N. Institute for Water, Environment and Health, has found that the UK and Japan have the most 'alert age' dams.
  • In both countries, average dam age has surpassed 100 years, a major cause for concern over their water storage infrastructure.

Once a large dam has reached the age of 50 years, whoever is in charge of its maintenance should be especially alert to the upkeep challenges and dangers an old dam can create. According to a new report by the U.N. Institute for Water, Environment and Health, dam keepers in the UK and Japan are most likely to be worried about the age of their water storage infrastructure. In both countries, average dam age has surpassed 100 years, double of what the report calls the “alert” age for large dams, defined as those with a height of at least 15 meters or a capacity of at least 3 million cubic meters (for dams between 5 and 15 meters high).

Have you read?

At the moment, the age of dams is reaching a critical point in many countries at the same time. The reason for this is the dam-building frenzy which occurred in the middle of the 20th century. In the late 1950s as well as in the 1970s, upwards of 1,100 dams were constructed every year. Since 1990, that number has dropped below 500 and below 300 since the year 2000.

a chart showing the number of alert aged dams around the world
Japan has the highest number of 'alert' aged dams. Image: Statista

The U.N. experts expect the number of new dam projects to remain low in the future, leaving the options of replacement or decommission for existing water storage infrastructure. Public safety and environmental concerns weighed against the cost and benefit of keeping a dam will decide their fates around the world. Already, dam failures (of all sizes of dams) have ballooned since 2005 and keep rising, having reached 175 incidents for the years 2015-2019.

The most common use for dams around the world is irrigation, followed by hydropower, water supply, flood control and recreation. According to the report, 40 percent of the world’s agricultural production depends on dams for its water supply. China – the country with most large dams by far – is also approaching “alert” age with the average dam constructed 46 years ago. The U.S. is the leader in dam removal, proving that the risk and cost associated with old dams can be eliminated altogether in many cases. In the past 30 years, the country has decommissioned more than 1,200 dams.

Loading...
Don't miss any update on this topic

Create a free account and access your personalized content collection with our latest publications and analyses.

Sign up for free

License and Republishing

World Economic Forum articles may be republished in accordance with the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Public License, and in accordance with our Terms of Use.

The views expressed in this article are those of the author alone and not the World Economic Forum.

Share:
World Economic Forum logo
Global Agenda

The Agenda Weekly

A weekly update of the most important issues driving the global agenda

Subscribe today

You can unsubscribe at any time using the link in our emails. For more details, review our privacy policy.

About us

Engage with us

  • Sign in
  • Partner with us
  • Become a member
  • Sign up for our press releases
  • Subscribe to our newsletters
  • Contact us

Quick links

Language editions

Privacy Policy & Terms of Service

Sitemap

© 2024 World Economic Forum