(I say this with a heavy heart as an avid carnivore)
Beef is astoundingly wasteful of water. You could take an hour-long shower and it would use about the same amount of water needed for a pound of beef. [2] and [3].
[1] http://gracelinks.org/blog/1143/beef-the-king-of-the-big-wat...
[2] http://www.wsscwater.com/home/jsp/content/water-usagechart.f...
[3] http://blog.epa.gov/healthywaters/2012/03/virtual-water-real...
I come from a country with more water than we know what to do with and it blows my mind that people in California will just throw perfectly good water on their lawn. I understand irrigating crops that you're going to eat, but a lawn? Seriously?
I keep hearing how places like California are chronically deprived of water and yet I keep seeing sprinklers everywhere. What gives?
This[1] says that "The typical suburban lawn consumes 10,000 gallons of water above and beyond rainwater each year." ... according to numbers quoted in other comments around here, that's worth about 10 burger patties.
No such laws or rules apply in my neighborhood, and I never water my lawn. For a few weeks or so in the summer it might turn brown, but that doesn't harm it. When rain comes, it turns green again.
Lawns do have some benefits. They have a significant cooling effect, which can save air conditioning costs. They filter dust and pollutants from the air. They reduce noise pollution. They remove carbon from the atmosphere (NASA says US lawns take out 17 teragrams of CO2 a year...although lawn mowers certainly put a lot back). See [1].
[1] http://cleanairlawncare.com/sustainable-lawn-care/benefits-o...
[1] http://www.waterfootprint.org/Reports/Mekonnen-Hoekstra-2012...
From Table 2, beef requires 7,477 m^3 of water per ton, which comes out to 330 gallons per 1/3 lbs. Table 3 says 15m415 m^3 of water per ton. I'm not entirely sure I understand why that's different from table 2, but that's 678 gallons per 1/3 lbs.
I just like having things in perspective, whereas the absolute amount of water that goes into producing a given amount of beef doesn't tell me a great deal. That's like me saying 'a cow weighs 1000 pounds so it feeds a lot more people than a head of lettuce' - it's superficially true, but not very meaningful.
Specifically, there is a certain amount of water that each human needs per day. Provide a human with less than that, and they will die.
BMWs do not have this property. The vast majority of humans have never owned and never will own a BMW, and they are still able to live rich, full lives.
When you say "satiate demand" for BMWs, what you're really saying is that the market finds the intersection of the supply and demand curves, and produces BMWs at that rate. When I see "satiate demand" for water, what I understand it to mean supplying every human with at least the minimum amount required to sustain life.
A free market for water will find the intersection of the supply and demand curves, just like it does for BMWs. However, the BMW example does not tell us anything about where that intersection lies, and whether it lies at a point where humans die of thirst or at a point where everyone gets what they need.
It is, ultimately, equivocation. Fulfilling demand for luxuries is different from fulfilling demand for necessities.
To sustain any given level of population, a corresponding (though not directly proportional) amount of transportation must exist, as not all necessities for life are available everywhere in sufficient quantity. Because of this, transportation is as much as requirement as is water (bough the latter undoubtedly serves a much more direct purpose). The capital goods which allow for transportation are provided in sufficient quantity to satisfy demand through a (mostly) well functioning market for boats, ships, trains, planes, and automobiles. BMW does not make up the whole of this market, but serves well as a synecdoche (this avoiding a tiresome list of all transportation capital good manufacturers), demonstrating the importance of the price as a signal, incentive, and motive for the fulfillment of human needs and wants.
I think it's perfectly reasonable. Let X be the amount of water a person needs to live. The amount a person is willing to pay for a unit of water when they already have X is finite. The amount a person is willing to pay when they don't have X is infinite. Thus, there is a discontinuity at X.
If you didn't mean BMWs specifically you could have said this earlier. How was I supposed to know you meant "all transportation" instead? It gets pretty tiresome when I reply to a comment and address something it says and then several comments later you come back and say, oh, I didn't actually mean what I said, I obviously meant something else.
With respect to the BMW example, I still stand by it, and I did not originally mean that BMW represented the entire transportation industry; their fundamental similarity is what is important here. There is nothing special about he market for water, and using transportation capital goods as a bridge between the water market and the luxury automobile market demonstrates their fundamental similarities well (though I would not suggest flushing a bus down the toilet).
The problem, again, is equivocation. You say that we could end water shortages by accurately pricing water. The problem is that when you say "shortage" in that context, you're using the economic definition wherein a shortage is a situation where some external force prevents A from selling something to B for a price they're both willing and able to accept. Whereas when we think of water shortages, we normally think of whether or not people are able to obtain enough water to continue living.
Yes, market pricing for water ensures there would be no "shortage" in the economic sense, by definition. But it tells us nothing about whether people would be able to obtain enough water to survive within such a market. Maybe they would, maybe they wouldn't, but you haven't demonstrated that they would.
A very strong case can be made that a market for water would provide enough water for all the individuals to use (in developed areas), as well as resolving the aforementioned issues, but it is impossible to prove on theory alone; we would have to test.