For comparison water ranges from $400 to $1000 now.
Haha um... no. Maybe you're talking about residential water rates? "Acre feet" is a unit used to measure agricultural water supplies only, because it is a ridiculously large amount of water. I pay about $2.10 per CCF for water at my house (approximately 4 gallons for one penny), which works out to a little over $900 per acre foot. The farmers I work with, by contrast, usually pay between $5 and $15 per acre foot for much larger quantities of water, and they bitch and moan about anything much higher than that. As a general rule, farmers pay less than 10% of what a municipal water customer will pay, in part because the federal government spent a few billion dollars back in the 1930s to build reservoirs and canals for them.
With those costs in mind, desalination really only makes the remotest kind of sense for supplying people's homes, not for growing crops. City water rates would approximately double or triple, but that's a cost most households can easily absorb because water is already so cheap. The only form of agriculture that can possibly operate at that market price for water is weed.
Which is fine! Everyone makes a big deal about supporting farmers "because everyone has to eat" but the simple truth is that we DO NOT have to grow food in the places where we currently grow food. No one farms in Manhattan, and yet Manhattan is still economically prosperous without a single farmer. You grow your food wherever it is cost effective to do so, and then you pay to ship it to wherever it is needed. We literally transport cargo ships full of grain across the Pacific Ocean and make a profit doing it, and I'm pretty sure we can truck your apples and cheese across state lines if we have to.
An acre-foot is 325,851 gallons, or roughly the amount of water a family of five uses in a year. residential use is implied, family of fice is in the description.
I think it might have something to do with scale, when you start talking about 56,000 acre-feet, it gets ridiculous using gallons - 18,247,656,000, wtf is 18 trillion gallons! Instead, a more meaningful metric is employed for communication 1 acre-foot=1 house...56,000 acre-feet is 56,000 homes,
56,000 is the size of San Diego's plant in Carlsbad. It supplies 8% of the counties water and cost a billion dollars (from the link). San diego county has 3 million people, California has 39.4 million. It would take $164 billion, at that price, to build desalination water for all residential use.
Clearly thats an enormous sum, for comparison the debt of california is $1,140 billion, desalination for all will add on 14% to total debt (really rough math to put things in perspective), chances are you wouldn't replace 100% of all water.
I stand by my statement, the cities of California aren't going to disappear in a Mad Max scenario. I also disagree they will experience a Cape Town scenario. The farmers will be screwed, but hollywood will remain, no need to fret over the Kardashians.
In Canada theres a large unfounded fear that America will invade and steal our water. Given the cost of a miltary invasion (2 trillion for Iraq), I suspect y'all would just build desalination plants. I doubt you want to deal with rebuilding our igloos and log cabins.