The health emergency poses new challenges to urban planning. The criteria of sustainability are broadened with those of health, and the concept of healthy city radically changes if extreme poverty is not taken into account. The awareness that individual health is synonymous with collective health is one of the lessons of Covid-19 that we should not miss.

Water pollution due to illegal gold mines is a serious problem in Ghana, a country in which 70% of the diseases are caused by unsafe water. Galamsey is a phenomenon that prevents the economic growth of the country and pollutes rivers and aquifers to lethal levels. This is the case of the Ghanaian protagonist of the short film Nothing Has Changed, finalist of the We Art Water Film Festival 4.

In the progress towards global sustainability, the access to water and sanitation plays a double role: it is at the same time a tool and a goal of the solutions. From agriculture to the domestic supply, it provides essential information to attain SDG 6. To achieve it, governments and companies need to take into account the enormous existing asymmetries and ensure that no one is left behind.

The overexploitation of aquifers is worsening the problems caused by the natural pollution of water in many areas with hydric stress. The levels of fluoride, arsenic and other chemical compounds that are harmful to health affect millions of people all around the world, causing a very serious health issue. This is the case described by the Mexican short film Necesidad que mata (A need that kills), finalist of the We Art Water Film Festival 3.

The access to water or the lack thereof defines two types of homes: the comfortable ones, which allow a dignified and healthy life, and the ones which cannot provide their owners with anything remotely similar. Many of the 2.185 billion people with no safe access to water dream of having it at home. This is the case of the Cameroonian protagonist of the short film Utopia, finalist of the We Art Water Film Festival 3.

Water shortages in many Venezuelan cities are worsened by power cuts and the deterioration of public services, especially affecting the poorest neighborhoods. Most of their inhabitants fight every day to obtain water outside the cities with the serious risks it entails. Others have been implementing a water survival strategy for decades. This is featured in the short film La camisa sucia (The stained shirt), finalist of the We Art Water Film Festival 3.

Water will always be there, but not water security. It is a more enveloping concept that allows experts to better communicate the complexity of the urban water cycle to citizens, making them participate in its management model, in its benefits and risks. Well informed users enable the creation of a context with a participatory and transparent governance in which we all feel involved. Water security goes beyond the simple access to water and implies constant work.

The unstoppable exponential growth of cities will turn us into an eminently urban species in a few decades. For life on Earth to be sustainable cities also need to be so, and this will not be possible without the smart technologies integrated in circular economy. Their implementation is a great challenge for poor economies, which are most overwhelmed by urban growth and are not able to supply water and sanitation. This needs to be an international responsibility because what happens in these cities will be decisive for life on Earth.