Population growth, rapid urbanization, and the need for more resilient infrastructure in the face of climate change are some of the global challenges that highlight the importance of commemorating World Toilet Day every November 19th. This day, promoted by the United Nations, aims to raise awareness about a service essential for health and the environment. The lack of adequate sanitation causes environmental pollution from wastewater and poses a serious threat to almost half of the world's population, who still lack access to these basic services, according to data collected in 2025 by the World Health Organization (WHO) and UNICEF. In Catalonia, the combination of prolonged droughts and torrential rains—increasingly frequent phenomena due to global warming—tests the capacity and resilience of infrastructure related to the water cycle. Although Spain has high standards in urban water services, three key challenges remain: wastewater collection and treatment, regeneration, and investment in facilities prepared to face the climate emergency.