As a biased omnivore, it would probably be a bit more useful to compare the calorie content of 1 lb of beef vs 1 lb of vegetables. I understand the point you're getting at but the bias might be a little bit too strong there.
shows 10.19 litres/calorie beef vs 1.34 liters/calorie vegetables. Which is an even greater distance than the gallons per pound I mentioned. This obvioulsy can't be right. I will argue that theory wise it makes sense that a plant based diet would use less than a diet consisting of eating animals that ate the plant based diet. The animals are expending energy! You could argue that we can feed animals lower water usage plants than we can feed humans, but does that really make a healthy animal for human consumption?
That said, there are other negatives associated with beef production and consumption :).
Soybeans have about 2000 calories / lb, based on the number Google gives me of 446 calories / 100g. A random website claims soybeans take 200 gallons of water to produce 1 lb, which comes out to about 10 calories / gallon.
That said, you can make huge gains just by switching from beef to pork or chicken. Pork uses about half the resources of beef, per pound, and chicken about a third. Eat your beefs for special occasions, eat chicken and pork if you want every-day meats.
Not sure I believe the animals are getting most of it in California but either way that's something that can be easily moved out of state. Almonds can't.
Growing water intensive crops like rice in California, which it grows a good deal of, is just stupid. That is an industry which needs to die. I'd argue the same for almonds, which are basically a water intensive cash crop.
Almonds use 10% of the state's water supply. The irony is that almonds and apricots have been grown in the Santa Clara valley and surrounding areas without irrigration until tech booms led to orchards being pulled out and replaced with office complexes.
That is an interesting and ironic thing to consider. And I think it's probably inevitable that California shifts its crop mix away from things like almonds, even if at one point they had been grown sustainably (and certainly rice, which is patently unsustainable, but easier to draw down from). Olives, for instance, grow very well in California and are a lot less water intensive than almonds and other trees in the stonefruit family. The downside is that trees take a long time to grow to productive maturity, and phasing one species out for another cannot be done overnight. I have no idea if a phase-out of one in favor of the other is already underway, and I would hazard a guess that if it is, it's proceeding glacially. But some sort of phase-out seems essential.
California's water reserves can't sustain the ridiculously wasteful agriculture that Californian farmers have been growing for decades, and a huge amount of California's water use is going towards agriculture to grow almonds, rice, and grapes in the desert.
Those crops are going to have to come from somewhere else pretty soon regardless.
1. Destroying the farming industry 2. Destroying the land entirely, and then destroying the farming industry.
The current situation is proof that the current level of agriculture is unsubstainable.
As a reference, a few quick searches[1] show that it takes:
5.4 gallons of water to grow a single head of broccoli
4.9 gallons of water to grow a single walnut
1.1 gallons of water to grow a single almond
[1] http://www.motherjones.com/environment/2014/02/wheres-califo...