Apart from land subsidence from urbanisation , substantial climate risks to urban sanitation arise from droughts, flooding and storm surges. Low flows from drought can lead to sedimentation, increase pollutant concentration and block sewer infrastructure networks . Flooding poses a greater risk for urban sanitation in low- and middle-income settings  where onsite systems are more common. Floodwater may wash out pits and tanks, mobilising faecal sludges and other hazardous materials leading to both direct and indirect exposure via food and contaminated objects and surfaces, and pollute streams and waterbodies . Floods also damage infrastructure; toilets, pits, tanks and treatment systems are all vulnerable .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report