Urban waters

From an estimated population of 9.7 billion inhabitants by 2050, about 60% will be living in urban areas. At present, 2021, close to 4 billion humans live in cities; Earth is therefore already a Urban Planet. The demands for water, energy, habitat and food in the next 30 years will rise increasing the pressure and valuation on water resources in cities. Cities alter the environment in several ways: changing the water cycle; increasing of water and air pollution; augmenting of impervious surfaces and decreasing infiltration to ground water. Moreover, uncontrolled urbanization provokes flood disaster risks, promoting urban catastrophic floods.