It does not rain as much as it said to be in London but it rains quite often and the rainwater managemnet I think is a great opportunity for the city to utilize technology in this area.

I thought of this subject because in the housing I'm living at the garden is being watered from a tap in a very old fashioned way.

When I had a quick look I found this page:
http://www.london.gov.uk/priorities/environment/looking-after-londons-water/managing-rainwater-and-drainage

and I think putting this matter on London authority agenda is a good step.