Hello Charles, Take a look ...

Hello Charles,

Take a look at Biopolus, they developed a remarkable way to decentralise the treatmeant of waste water in a wonderful greenhouse park that blends in with the city.

Besides the different solutions that are already mentioned, such as rainwater harvesting etc. The thing that makes a city smart is the way all these different solutions work together to react to different, extreme, circumstances. For instance at the prediction of heavy rainfall the city will actively drain natural water ways and water retention at forehand so there is enough space for water storage at the time of heavy rainfall.

In the Netherlands we are currently working on these kind of automated systems, not only to prevent our cities from flooding, but we can also win energy from carefully managed differences in water level. Take a look at the Dutch water sector.