In the late 19th century rich people in LA bought many properties upstream of Owens valley, on the Owen’s river, and diverted the water to LA leaving farmers in Owens valley without the water they historically had and needed for their farms.

Diverting water from farmers != causing the poor to die of thirst. That latter scenario of yours was just ridiculous.

the idea that "leave it to the market" will solve all problems is ridiculous as is shown by the historical example I gave.

The idea that the only market is a robber-baron friendly totally unregulated one is an absurd strawman.

The water issues in California could be addressed by trading (say) half the water currently going to agriculture. Everyone would be better off, including those poor you pretend to care about.

It’s not a straw man, that’s exactly what a whole lot of people on here believe is the one true way.

So your idea is that the government will decide and enforce that roughly half the water is not allowed for agriculture?