The new building will reuse rain water to flush the toilets and a solar electric generating system will be installed on the roof.

BBC: Artist impression of the new building

Thames Water has admitted its drainage system has been overwhelmed by recent heavy rain and flooding.

BBC: Thames Water says drainage system 'overwhelmed'

Water behind the Cutzamala dam system is below normal levels after a lack of rain in 2008, according to officials.

CNN: Water cutbacks on tap for Mexico City