Many crops use much more water than Almonds [0], I guess they're just fun to pick on. It'd be interesting to see a calorie/water comparison of many foods.
Also, my family's farm spends more money on well water than the government supplied water due to the high cost of electricity for pumping.
I do agree that a real market for water might help. The root of the problem really is that we are farming in a desert and relying on water from other locations. However, the desert does otherwise provide a great climate for efficiently/consistently producing many crops.
[0] http://www.latimes.com/opinion/op-ed/la-oe-gleason-almond-fa...