Hoover Dam

They build a huge stonking dam and all they needed was beavers and trees . But they killed all the beavers off for meat and fur and chopped down all the trees. Now nature is coming back to bite with a vengeance.

 

Beaver dam building seems to be their only hope.
If they had helped nature and worked with it instead of pouring millions of tons on concrete into the chasm they might not be facing water shortages now.
Though that probably wouldn't have stopped the failure of snow to cap the mountains that help supply lake mead.