Owens valley is basically dried up from the water that LA takes. It's interesting as you drive in the towns in the Valley and you see all the LA Department of Water and Power offices over 200 miles from Los Angeles. The courts had to force the LA DWP to quit taking too much water from the streams that feed Mono Lake as it was in danger of drying out.
It isn’t dried up, they maintain a certain water level in the various lakes.
Yep, Owens valley is basically an environmental disaster created by LA. So in the grand scheme of things, buying water from NorCal is better than stealing from the Owens valley through antiquated water rights.
But really, California (and really the entire Western US) needs a water rights governance overhaul. Right now the focus is all on urban water use, which is practically negligible compared to the agricultural water rights usage.