It may not be all farmers, but farming as a whole is _the_ problem. Without agriculture there is no California drought. Rational solutions to this problem are going to threaten people's "livelihoods and ways of life", there is no getting around that. I don't see how beating around the bush helps anyone.
To put things in perspective, alfalfa and corn both of which are overwhelmingly fed to animals and the former of which is exported in large quantities to be fed to animals in Asia, together consume more water annually than all residential users. And those are just two, low value (per acre-foot of water consumed) crops.
As for what should be done:
1) The implementation date for sustainable groundwater pumping enforcement should be moved up from 2040(!) to 2018.
2) As an intermediate step in the elimination of prior appropriation, several secondary doctrines that reduce transferability and encourage overuse should be eliminated. Including but not limited to: no harm to juniors, anti-speculation, beneficial use, and appurtancy.
3a) Put together an all star team of taking clause and due process experts to figure out the least expensive way to seize and retire all water rights consistent with the fifth and fourteenth amendment, then do that.
3b) Replace prior appropriation with an annual water permit auction for surface and subsurface sources. Use the money to pay off whatever debt was incurred in 3a and thereafter use the money for the general welfare.