Secretary-General Antonio Guterres warned Tuesday that by 2050 global demand for fresh water is projected to grow by more than 40 percent and at least a quarter of the world's population will live in countries with a "chronic or recurrent" lack of clean water.
He told the Security Council that "strains on water access are already rising in all regions," noting that three-quarters of the 193 UN member states share rivers or lake basins with their neighbors.
"Water, peace and security are inextricably linked," Mr. Guterres said. "Without effective management of our water resources, we risk intensified disputes between communities and sectors and increased tensions among nations."
The secretary-general said the United Nations is ready to engage in preventive diplomacy to keep the competition for water from sparking conflicts.
Bolivian President Evo Morales, whose country currently holds the council presidency, noted that since 1947, some 37 conflicts have taken place between countries related to water.
"Our planet, the human family and life in all its myriad forms on Earth are in the throes of a water crisis that will only get worse over the coming decades," he said.
"If current patterns of consumption continue unabated, two-thirds of the world's population will be facing water shortages as a daily reality by 2025," Mr. Morales added.
Right now, he said, more than 800 million people lack access to safe drinking water and more than 2.5 billion don't have basic sanitation.
Morales, who presided over the meeting, said the limited availability of fresh water underscores the importance of tackling the issue and ensuring that access to clean water is shared and doesn't become "a pretext for domestic or international conflict."
British Ambassador Matthew Rycroft said the world has already seen what can happen "when the waters run dry," pointing to drought in Somalia that is driving acute food shortages and threatening famine and a lack of clean water that is exacerbating the crisis sparked by Boko Haram in northeast Nigeria and sickening thousands.
He said the world currently is not on track to meet UN goals for 2030 calling for improved water security, access to drinking water, and sanitation, as well as stronger management of water resources shared by countries.
In South Asia, Mr. Rycroft said, 1 billion people across Afghanistan, Bangladesh, Bhutan, China, India, Nepal, and Pakistan rely heavily on just three rivers, but "despite facing similar problems posed by water demand and climate change, regional collaboration between these countries is limited."
Rycroft said Britain has provided $30 million over the past five years to support a regional approach to "identify and resolve challenges affecting these transboundary waters."
But to tackle the problem globally, he urged the world's developed nations to also invest in delivering improved water security within and between states.
In one example of regional cooperation, Ethiopian Ambassador Tekeda Alemu said that while there are differences between the six countries that are upstream and downstream on the Nile River, those nations negotiated for 13 years to produce an agreement on using its waters. It was signed by all six nations and is awaiting ratification by three of them.
"The cooperation between Ethiopia, Egypt, and Sudan and the signing of the Declaration of Principles by the leaders of the three countries is also another manifestation of regional cooperation that needs to be enhanced further," he said.