The Netherlands has a long history when it comes to water management. Because of the geological position of the Netherlands, in the delta of European rivers like the Meuse, Rhine and Schelde, water management has become very important in everyday life. The Dutch have managed pretty well the last fifty years, but times are changing. Today we are facing the threat of a global climate change. It is expected that Western Europe will face more extreme weather: more rain in shorter periods and longer periods of drought. Another aspect is the continuous growth of urban development, which results in larger areas of paved surfaces and ongoing decrease of retaining and / or infiltration areas.