Can a mega-city mobilize its 22 million citizens to become water sustainable? José Cohen & Lorenzo Hagerman try to find out.

Mexico City was built not near water but in the middle of a lake. To supply it with fresh water is such a task that it makes it compulsory to bring it from other states.

In addition once sewage water leaves the city it ends up in agriculture.

This film is an environmental case study of the Valley of Mexico as it struggles to save itself while its population grows.