Quarter of planet faces looming water shortage

BANGALORE, India — Countries that are home to onefourth of Earth’s population face an increasingly urgent risk: the prospect of running out of water.

From India to Iran to Botswana, 17 countries are currently under extremely high water stress, meaning they are using almost all the water they have, according to World Resources Institute data published Tuesday.

Many are arid countries to begin with. Some are squandering what water they have. Several are relying too heavily on groundwater, which instead they should be replenishing and saving for times of drought.

In those countries are several big, thirsty cities that have faced acute shortages recently, including São Paulo, Brazil; Chennai, India; and Cape Town, South Africa, which in 2018 narrowly beat what it called Day Zero — the day when all its dams would be dry.

“We’re likely to see more of these Day Zeros in the future,” said Betsy Otto, who directs the global water program at the World Resources Institute.

Climate change heightens the risk. As rainfall becomes more erratic, the water supply becomes less reliable. At the same time, as the days grow hotter, more water evaporates from reservoirs just as demand for water increases.

Mexico’s capital, Mexico City, is drawing groundwater so fast that the city is literally sinking. Dhaka, Bangladesh, relies so heavily on its groundwater for both its residents and its water-guzzling garment factories that it now draws water from aquifers hundreds of feet deep. Chennai residents, accustomed to relying on groundwater for years, are now finding there’s none left.

Today, among cities with more than 3 million people, World Resources Institute researchers concluded that 33 of them, with a combined population of over 255 million, face extremely high water stress, with repercussions for public health and social unrest.

By 2030, the number of cities in the extremely high stress category is expected to rise to 45 and include nearly 470 million people.

A lot can be done to improve water management, though. First, city officials can plug leaks in the water distribution system. Wastewater can be recycled. Rain can be harvested and saved for lean times: lakes and wetlands can be cleaned up and old wells can be restored. And farmers can switch from waterintensive crops, like rice, and instead grow less-thirsty crops like millet.

“Water is a local problem and it needs local solutions,” said Priyanka Jamwal, a fellow at the Ashoka Trust for Research in Ecology and the Environment in Bangalore.