São Paulo is in the "green" but they were supposedly around two weeks from running out of water for municipal distribution in 2014/2015. A city of that size without water would not do well.

https://en.wikipedia.org/wiki/2014%E2%80%932017_Brazilian_dr...

https://www.smartcitiesdive.com/ex/sustainablecitiescollecti...

EDIT: added timeframe