Nearly one-quarter of the world's population lives in countries with extremely high water stress levels due to withdrawing far more water annually for public consumption, agriculture, energy production and industrial purposes than nature is capable of replenishing, according to the World Resources Institute.
Most of the 17 countries that the institute's, or WRI's, updated Aqueduct Water Risk Atlas identified as facing extremely high stress — meaning each withdraws more than 80% of the annual surface and ground-water supplies — are largely in South Asia, the Middle East, North Africa and sub-Saharan Africa. In addition, more than two dozen countries have high water stress levels and withdraw 40% to 80% of their water supplies. Those high-stress countries include Mexico, Afghanistan, Iraq, Italy, Portugal, Syria, Turkey, Greece and Belgium. The WRI tool uses data from the 1960s through 2014 and excludes anomaly events and, for the first time, also accounts for coastal flood risks and groundwater table declines.
But even countries with overall moderate water scarcity issues can have hotspots, WRI noted in a news release. While the U.S. is ranked 71 globally on water scarcity, the state of New Mexico has extremely high water stress, on par with what the United Arab Emirates and Eritrea in East Africa are facing.
Water scarcity can pose a threat to the supply chains of corporations that rely on crops for their products, such as to produce beer, and can make it harder for utilities to operate their power plants. Some such companies have begun to address water risks in their supply chains, and environmental shareholder activist group Ceres in 2018 developed, in coordination with more than 40 institutional investors, a water toolkit to evaluate and act on water risks in investment portfolios.
More broadly, scientists and other experts have found water scarcity can exacerbate conflict and migration, threaten food supplies, and may even push cities toward a "day zero" event in which they run out of water entirely. Moreover, scientists warn water scarcity issues are set to increase due to climate change and socioeconomic growth. Climate change is already affecting global water cycles, prompting prolonged and more severe droughts and causing some regions to see stronger rainstorms and more frequent flooding.
"If you are in an area of high or extremely high water stress where a lot of available water is already being withdrawn, if you then hit a drought ... you are really in trouble. ... The various sectors that need that water are not going to have water or taps are going to run dry," WRI's Global Director of Water Betsy Otto said in a press call.
But Otto also pointed out that water scarcity can be reversed.
The term day zero in relation to water shortages came about after officials in South Africa's Cape Town in January 2018 announced the city of 4 million people was three months away from its taps running dry. The city ended up averting the crisis, for at least a year, through such measures as water tariffs, using a new water-pressure system, and prohibiting people from using water for nonessentials such as to fill their swimming pools and water their lawns.
"Water stress is not destiny even for many of the hot spots" the tool identified, Otto said. Countries and localities can change their trajectory "with better information, better planning, and water management and solutions that we know work such as more efficient irrigation, fixing leaks, recycling wastewater and protecting source watersheds."