Water and global health are deeply interconnected, influencing disease transmission, public health monitoring and resilience to climate-related events. In this Q&A, Vikki Williams, Digital Water Leader at Arup, shares insights into how water systems impact health outcomes and what needs to change to improve prevention and response.
Why is water such a critical global health issue—beyond just drinking water access?
Water is a major pathway for disease transmission across the entire water cycle, not only through drinking water but also via sanitation systems, bathing water, irrigation, water reuse and food production. Poorly managed water systems allow pathogens to circulate between people, animals and the environment.
Water is also part of a wider public-health system: wastewater provides a population-level health signal through wastewater-based monitoring, which aggregates biological markers from communities to digitally monitor disease prevalence, antimicrobial resistance and environmental pollution. Because biomarkers can appear before symptoms, wastewater-based monitoring can act as an early-warning system, supporting public-health decision-making at community, city and regional scales.
How do floods and extreme weather events increase waterborne disease outbreaks?
They place acute stress on water and sanitation systems. Flooding can overwhelm wastewater and sanitation infrastructure, allowing sewage to mix with surface water and drinking water sources, increasing exposure to disease causing pathogens such as Cholera, Leptospirosis and Hepatitis A. Damage to water treatment and supply infrastructure can disrupt access to safe water, forcing communities to rely on untreated or contaminated sources.
Flooding also mobilises pathogens from soils, livestock waste and urban runoff, while displacement and overcrowding often degrade sanitation conditions. These events represent rapid health shocks, highlighting the importance of early warning systems, digital monitoring of health markers, and resilient or decentralised approaches that support faster detection and response.
What are the biggest mistakes in waterborne disease prevention programmes—and how can they be avoided?
One of the biggest mistakes in waterborne disease prevention is focusing too narrowly on drinking water while overlooking wastewater, sanitation and wider environmental pathways where pathogens continue to circulate. Fragmented governance deepens the problem, with public health, water, environmental and agricultural bodies often working in silos and creating surveillance gaps. Prevention programmes also tend to remain reactive, responding after outbreaks rather than investing in earlier warning.
These risks can be reduced through a whole water cycle and catchment approach, supported by sustained investment in surveillance infrastructure, including environmental and wastewater monitoring. Better integration of monitoring data with public health decision making, clear governance and coordinated cross-sector action are critical to turning early detection into timely, effective public health responses.
About the expert
Vikki Williams is Digital Water Leader at Arup, specialising in the integration of digital technologies and data-driven approaches to improve water system performance, resilience and public health outcomes.
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