A report jointly released by the United Nations Environment Programme (UNEP) and the Asian Institute of Technology (AIT) warns that hundreds of millions of people in South Asia are at risk from increasing water scarcity as water supplies in three of the region’s largest river basins become increasingly vulnerable. Although one-fourth of the world’s population live in this region, they have access to less than five percent of the planet’s freshwater resources.

The river basins under threat are the Ganges-Brahmaputra-Meghna (GBM), the Indus, and the Helmand. Running through eight countries, including China and India, they provide water for 750 million people.

Jinhua Zhang, regional coordinator at the UNEP Division of Early Warning and Assessment, told SciDev.Net that the “per capita availability of freshwater is declining, and contaminated water remains the greatest single environmental cause of human illness and death.”

Experts cite several reasons for the increased scarcity. According to a press release issued by the UNEP, high population growth, over-exploitation, pollution, climate change, and inadequate cooperation among countries are the major threats to these river basins and the people who depend on them.

UN Under-Secretary-General and UNEP Executive Director Achim Steiner stated, “These river systems are major economic arteries as well as social and environmental assets for South Asia. Investing in sustainable management is thus an investment in the current and future prosperity of Asia and will be a central and determining factor underpinning the transition to a resource efficient, sustainable Green Economy.”

Despite growing awareness of the major threats to the river basins, mitigating the human and environmental cost will not be easy. According to Zhang, controlling pollution and general water management depends on the affected countries working together to create solutions. He also stressed that improving people’s knowledge of the vulnerability of these freshwater resources is “essential so that policymakers can manage this vital resource for the benefit of their people, their economies, and the environment.”