I had thought that the high water use of California's Central Valley almond trees was something that was relatively widely known. I know I've encountered in in a variety of readings over the last couple of years, and I haven't been specifically trying to research it.
This is something that has already been written about a fair amount; is it really fair to expect him to "do his homework" for the counter to your claim when it's based on what is, to some, common knowledge? Moreover, the poster that you had already replied to above included two links to articles about the cost (in water) of growing various things. If you feel the need to "check the numbers", I think the burden might be on you to go find them.
This is something that has already been written about a fair amount; is it really fair to expect him to "do his homework" for the counter to your claim when it's based on what is, to some, common knowledge? Moreover, the poster that you had already replied to above included two links to articles about the cost (in water) of growing various things. If you feel the need to "check the numbers", I think the burden might be on you to go find them.