Metrics for access to water and sanitation need structural changes

Climate change is a negative equaliser for access to safe water and sanitation around the world. Historically, low-income and middle-income countries have been the least likely to be on track for achieving Sustainable Development Goal (SDG) 6, which calls for the availability of water and sanitation for all.¹ However, recent climate-fuelled disasters are also highlighting the fragility of water and sanitation systems in high-income countries. In 2024, hurricanes Helene and Milton intensified rapidly in the Gulf of Mexico before hitting large areas of southern USA. Many residents in Asheville, NC, USA, were left without running water. Restaurants and schools were temporarily closed due to public health concerns of unsafe water, and many relied on buckets to flush their toilets.²

The effects of climate change on water and sanitation systems worldwide highlight that simply counting who does or does not have access to these services is not enough. Before the hurricanes hit, WHO's Joint Monitoring Programme for Water Supply, Sanitation, and Hygiene would have counted people in Asheville as having access to safely managed water and sanitation services. That status changed very quickly in the aftermath of hurricane Helene. Climate change affects the reliability, quality, and sustainability of water sources and infrastructure, which cannot be fully understood through a basic count of access alone.

Metrics for access to water and sanitation need to more accurately reflect the complexity brought on by climate change and to go beyond simply measuring who has the resources and who does not.⁸ This goal can be achieved by tracking how long these systems are exposed to, and disrupted by, climate-related hazards and more granularly tracking the places within countries that are most vulnerable to these threats. This approach will allow us to accurately assess access—a lesson that can be applied to other crucial forms of health and social infrastructure.