Because there isn’t a gigantic reservoir next to Folsom?
https://www.latimes.com/california/story/2021-07-27/historic...
There. Is. Not. Enough. Water. Anything else you hear is just a lie. I drive by it every day for the past 10 years, it goes up and down a lot but the levels this year are just record breaking, in a bad way.
At zero cost for usage sure. But there is plenty of water if you price it.