Climate change is intensifying threats to public health by disrupting water and sanitation systems. Hazards such as extreme heat, drought, wildfires, flooding, and sea level rise are increasingly compromising access to clean water and safe sanitation across the United States. Climate-related failures in these systems, as seen during events such as Hurricane Katrina, Hurricane Helene, and California’s 2012–2015 drought, have led to disease outbreaks, mental health challenges, economic hardship, social inequities, and long-term infrastructure challenges. These disruptions fall most heavily on frontline communities, reflecting disparities in exposure, infrastructure reliability, and health outcomes. Here are five ways climate change affects public health through water and sanitation systems:
1. Extreme temperatures
Extreme heat reduces water availability, concentrates pollutants, and accelerates the growth of toxins, increasing exposure to waterborne contaminants and harmful algal blooms. Extreme cold can also damage water infrastructure and cut off essential services.
2. Drought
Droughts contribute to waterborne diseases, contamination of private wells and community water systems, and hygiene-related illnesses caused by limited water for sanitation, with socially vulnerable populations facing greater barriers to safe drinking water.
3. Wildfires
Wildfires can contaminate water systems by depositing ash and sediment into source waters and mobilizing toxic chemicals within drinking water distribution systems, often triggering boil-water or “do not drink” advisories.
4. Flooding and extreme storms
Floods can introduce chemical contaminants into water supplies, overwhelm septic systems, and spread pathogens that increase risks of gastrointestinal illness, skin infections, and other health impacts, particularly in low-income and overburdened communities.
5. Sea level rise
Sea level rise can degrade coastal freshwater supplies through saltwater intrusion and increase flooding of water and sanitation infrastructure, threatening access to safe drinking water.
Climate change is increasingly disrupting water and sanitation systems, intensifying public health risks, and contributing to mental health challenges, economic hardship, and social inequities. Learn more about the challenges and responses in the Pacific Institute issue brief “Connecting Climate, Water, Equity, and Public Health in the United States.”