Las Vegas recycles almost 100% of its indoor water usage and minimizes outdoor usage. They pay you to remove your lawn and almost all of them are gone.
In 5-10 years, if this ends up like many are predicting (and I don’t know if it will or not), you are going to see people by the hundreds or thousands appealing their property tax assessments, saying their land is effectively worthless if water is too expensive or unavailable. They’ll get denied but some of them will contest the denial and file suit. And eventually one wins in court. Then everyone contests and everyone wins. And the only land that can be taxed has water rights. And unless the farmer plans to get his alfalfa to market via helicopter, he’s gonna have to pay the taxes or the roads disappear. He’s proper F’ed.
Just because people don't eat the alfalfa doesn't mean it isn't ultimately feeding people. Cows eat a ton of alfalfa, and we get both meat and milk from them. So it is feeding people, just indirectly.
PDCAAS and DIAAS by livestock are in the highly efficient category even after alfalfa water usage. Soy is just mid-tier.
So, depends on your body's protein needs. Vegan/vegetarian is just a choice and not for everyone.
[edit: Soy Milk protein require 2.9x less water than Caw Milk protein, DIAAS adjusted: 1 / (0.28 * 1.25)]
PDCAAS [0]
Soy 0.92 - Beef at 0.94 (Beef 2% better)
DIAAS [1]
Soy 0.91 - Beef 1.116 - Whole milk 1.14 (Beef 23% better, Caw milk 25% better)
WATER footprint [2]
Soy Milk is 28% of caw milk (Soy 257% better)
Soy Burger is 28% of caw milk (Soy 1329% better)
CALORIC / PROTEIN fed population [3]
MAD (mean American diet) 341m - Plant-Based 531m (plant 56% better)
1: https://en.wikipedia.org/wiki/Digestible_Indispensable_Amino... No data for Soy PDCAAS in that page and Beef has a different number as the first source. The difference isn't significative though.
2: > The water footprint of the soy milk product analysed in this study is 28% of the water footprint of the global average cow milk. The water footprint of the soy burger examined here is 7% of the water footprint of the average beef burger in the world.
https://www.waterfootprint.org/resources/Ercin-et-al-2012-Wa...
3: > [caloric and protein] At 3% in both metrics, beef is by far the least efficient [...] legume-dominated plant-based diets substitute beef with a dietary shift potential of ≈190 million [current US] individuals.
https://iopscience.iop.org/article/10.1088/1748-9326/11/10/1...
Obviously the production method of soy/burger/milk is significant, however others sources show rougtly the same order of magnitude: https://watercalculator.org/water-footprint-of-food-guide/
> depends on your body's protein needs.
For an higher protein/calorie ration, Quinoa is in range of soy' water footprint, and legume protein concentrates fit as well.