Adequate housing starts with water and sanitation

Every year on October 31, World Cities Day raises awareness of urbanization trends and challenges and promotes international cooperation to build more equitable, sustainable, and inclusive cities. Around 55% of the world’s population lives in towns and cities, and urbanization is projected to reach almost 70% by 2050, with much of this growth in Asia and Africa. The 2026 observance, "Regenerating the City: Adequate Housing for All,” focuses on how urban regeneration, combined with housing and informal-settlement strategies, can deliver adequate housing and create more inclusive neighborhoods that are resilient to climate-related risks (1).

According to UN-Habitat’s World Cities Report 2026, up to 3.4 billion people lack secure, safe, and adequate housing, including more than one billion living in informal settlements and slums (2). Adequate housing is not just about four walls and a roof: under international human rights law, it includes access to safe drinking water and sanitation (3). In many informal settlements, residents share overcrowded toilets and rely on irregular water sources, increasing their risk of diarrheal disease, typhoid, and cholera. Cholera can spread especially fast in crowded cities: along the West African coast, from Benin to Mauritania, at least half of all cholera cases reported between 2009 and 2015 occurred in just three cities: Accra, Freetown, and Conakry (4).

Improvements do not always require rebuilding. A 2026 study of 5,700 households in informal settlements in Delhi, Nairobi, and Kampala found that people using shared toilets meeting basic quality standards, such as cleanliness, water, handwashing facilities, lighting, and a lock, were about half as likely to report diarrhea (5). As cities plan their regeneration, investing in water and sanitation in existing neighborhoods is one of the most direct ways to reduce waterborne disease.