The world is facing a 40-per-cent shortfall in water by 2030 unless authorities dramatically improve management of the resource, the United Nations warned Friday.
"There is enough water available to meet the world's growing needs, but not without dramatically changing the way water is used, managed and shared," it said in its annual World Water Development Report, released in New Delhi and Paris.
Governments need to change how they assess, manage and use the precious resource in the face of ever-rising demand and the over exploitation of groundwater reserves.
"Unless the balance between demand and finite supplies is restored, the world will face an increasingly severe global water deficit," it said.
Sustainable water use and sanitation are "inextricably linked to climate change, agriculture, food security, health, energy, equality, gender and education," said Michel Jarraud, chief of the UN Water agency and secretary-general of the World Meterological Organization.
The report was released ahead of World Water Day on March 22.