Fuck my groceries. Food, as a percentage of household spending, is historically cheap. Charge the farmers the same price they charge everyone else, and the farmers will raise their prices accordingly. If that means I can't afford California's products, I'll choose another product. None of the things that California grows are necessary staples. If that means the farmers aren't competitive any more, then they should choose a line of work whose profitability doesn't depend on government largess and piping in water from god knows where.
It's nonsense really. You don't subsidize a limited, necessary resource. You let the supply demand curve determine the optimum price, and then if poor people can't afford to get drinking water, you subsidize them directly. Not to mention, when the price of water reaches its natural level, new sources like desalinization become economically feasible.