In Urban environment especially, you can harvest rain to collect water. In most of the cases, it would be drinkable also if you filter it. Urban environments are more dependent upon utility water supply & if that is broken, there is a serious crisis.

https://www.youtube.com/watch?list=PLOkE-zSvY6R_MWZfqmE3AJoIePywBE3ZQ&v=JHo4NBxALI4&feature=emb_logo

 

https://twitter.com/BTPrepper/status/1527365492951789571