This thread is long so this comment will likely fall pretty quickly, but this page is pretty telling in terms of usage by sector: http://www.ppic.org/main/publi

This thread is long so this comment will likely fall pretty quickly, but this page is pretty telling in terms of usage by sector: http://www.ppic.org/main/publication_show.asp?i=1108 http://www.ppic.org/main/publication_show.asp?i=1108 1. Environmental 50% 2. Ag 40% 3. Urban 10% (btw, this is particularly topical when my landlord just informed us he'd be swapping our shower heads for lower-flow ones due to increased costs in Southern Cal (bringing a toothpick to a gun fight?)) The thought process for how to decrease use, though, would be: 1. Can we tap into environmental use and, if so, how much, or is that verboten? 2. If no, which ag can we forgo with the least human/economic impact? 3. If no easy answer looking at both human and economic impact of ag, which ag can we forgo with the least human impact (e.g., if none of us had an almond ever again, would the world be worse off for it? That makes killing almonds purely economic) 4. If there's not enough from 1-3, then we've probably gotten to a life-threatening lack of water and so we get rid of crops that have the least "nutritional" value (i.e., crops that are best at sustaining life are the ones we keep) 5. If we still can't support life, looks like it's time to desalinate, create a pipeline from east or move Of course, even though it's a drop in the bucket, we should just immediately save the 5% that's used for urban and residential landscaping (see article; ~50% of urban use is landscaping) because there's nothing "essential" about that even though there would be an economic impact (and a whole lotta angry golfers).