Prof Kaveh Madani, who led the report, said while not every basin and country was water bankrupt, the world was interconnected by trade and migration, and enough critical systems had crossed this threshold to fundamentally alter global water risk. The result was a world in which 75% of people lived in countries classified as water-insecure or critically water-insecure and 2 billion people lived on ground that is sinking as groundwater aquifers collapse. Conflicts over water had risen sharply since 2010, the report said, while major rivers, such as the Colorado, in the US, and the Murray-Darling system, in Australia, were failing to reach the sea, and “day zero” emergencies — when cities run out of water, such as in Chennai, India — were escalating. Half of the world’s large lakes had shrunk since the early 1990s, the report noted. Even damp nations, such as the UK, were at risk because of reliance on imports of water-dependent food and other products. “This report tells an uncomfortable truth: many critical water systems are already bankrupt,” said Madani, of the UN University’s Institute for Water, Environment and Health. “It’s extremely urgent [because] no one knows exactly when the whole system would collapse.”
About 70% of fresh water taken by human withdrawals was used for agriculture, but Madani said: “Millions of farmers are trying to grow more food from shrinking, polluted or disappearing water sources. Water bankruptcy in India or Pakistan, for example, also means an impact on rice exports to a lot of places around the world.” More than half of global food was grown in areas where water storage was declining or unstable, the report said. Madani said action to deal with water bankruptcy offered a chance to bring countries together in an increasingly fragmented world. “Water is a strategic, untapped opportunity to the world to create unity within and between nations. It is one of the very rare topics that left and right and north and south all agree on its importance.” The UN report, which is based on a forthcoming paper in the peer-reviewed journal Water Resources Management, sets out how population growth, urbanization and economic growth have increased water demand for agriculture, industry, energy and cities. “These pressures have produced a global pattern that is now unmistakable,” it said.