Introduction Climate change is one of the greatest global challenges of the 21st century. Rising temperatures, changing rainfall patterns, extreme weather events, and sea-level rise directly affect the availability, quality, and sustainability of water, sanitation, and hygiene (WASH) services. Safe WASH is fundamental to public health, education, livelihoods, and environmental sustainability. In both global and Indian contexts, climate change is emerging as a serious threat to achieving universal WASH coverage and the Sustainable Development Goals (SDGs). How climate change affects WASH Water availability Changing rainfall patterns lead to droughts in some areas and floods in others, disrupting water supply systems. Melting glaciers and reduced groundwater recharge threaten long-term availability of freshwater. In India, states such as Rajasthan and Maharashtra face increasing drought risk, while Assam and Bihar are prone to recurrent floods, both of which directly impact drinking water sources. Water quality Floods and cyclones contaminate drinking water with sewage, industrial effluents, and chemicals. Higher temperatures promote algal blooms and bacterial growth in water bodies, increasing health risks. In coastal areas, saltwater intrusion due to sea-level rise is reducing the quality of groundwater, as seen in parts of West Bengal and Odisha. Sanitation systems Flooding damages toilets, septic tanks, and sewage treatment plants, leading to environmental contamination. Drought conditions make it difficult to maintain sanitation facilities due to water scarcity. Informal settlements and slums, where sanitation systems are often fragile, are highly vulnerable to climate shocks. Hygiene practices Lack of reliable water supply limits basic hygiene, including handwashing, bathing, and menstrual hygiene management. During disasters, hygiene often becomes a secondary concern, leading to outbreaks of diarrhoea, cholera, and skin infections. Global evidence of climate-WASH linkages Small Island Developing States (SIDS): Face severe water scarcity due to sea-level rise and saltwater intrusion. Sub-Saharan Africa: Droughts are reducing access to safe water, increasing dependency on unsafe sources. Asia-Pacific Region: Intensifying cyclones and monsoons frequently damage water and sanitation infrastructure. According to the Intergovernmental Panel on Climate Change (IPCC) 2022 Report, climate change is expected to increase risks of diarrhoeal diseases through impacts on water and sanitation systems. Impact on Health Contaminated water during floods increases the spread of water-borne diseases like cholera, typhoid, and hepatitis A. Poor sanitation and hygiene under climate stress heighten the risk of vector-borne diseases like dengue and malaria. Malnutrition is worsened by repeated diarrhoeal infections linked to unsafe WASH conditions in climate-affected areas. Indian Context Vulnerabilities Flood-prone regions (Assam, Bihar, Uttar Pradesh) often face breakdown of sanitation and water supply systems during monsoons. Drought-prone regions (Rajasthan, Bundelkhand, Vidarbha) experience acute water scarcity, affecting both drinking water and hygiene. Coastal states (Odisha, West Bengal, Tamil Nadu) are exposed to cyclones that damage water and sanitation infrastructure. Government responses Jal Jeevan Mission (JJM): Promotes source sustainability measures such as recharge structures and greywater management. Swachh Bharat Mission (SBM) – Phase II: Emphasises solid and liquid waste management with climate-resilient approaches. National Action Plan on Climate Change (NAPCC): Includes the National Water Mission, focusing on water-use efficiency and resilience. State Action Plans on Climate Change (SAPCCs): Address localised climate impacts on WASH infrastructure. Strategies for climate-resilient WASH Diversification of water sources: Rainwater harvesting, aquifer recharge, and desalination in coastal regions. Robust infrastructure: Toilets and water systems designed to withstand floods and cyclones. Community-based management: Local monitoring of water quality and collective maintenance of WASH facilities. Integration with disaster management: Ensuring WASH is prioritised in relief and rehabilitation. Technological innovation: Use of solar pumps, smart monitoring, and water-efficient sanitation systems. Conclusion Climate change poses a significant threat to achieving universal WASH coverage. Its impacts on water availability, quality, sanitation systems, and hygiene practices have far-reaching consequences for public health and sustainable development. In India and globally, building climate-resilient WASH systems is essential. This requires a combination of infrastructure investment, behavioural change, and policy integration with climate and disaster management frameworks. Ensuring WASH security in the face of climate change is not just an environmental challenge but a health and human rights imperative. References Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report, 2022. WHO/UNICEF Joint Monitoring Programme, Progress on Household Drinking Water, Sanitation and Hygiene, 2023. Ministry of Jal Shakti, Government of India – Jal Jeevan Mission and Swachh Bharat Mission documents. National Action Plan on Climate Change (NAPCC), Government of India, 2008 and updates.