The actual water embodied in the exported almond is trivial. A bunch of water is lost in evaporation, but I don't know how that evaporation compares between these various food items, I got the impression that a ton of water is dumped on the almond trees at some critical moments, so I'd presume most goes back into the ground? Some water may be unsuitable for reuse even if it doesn't evaporate.

There is not a water-gallon's worth of hydrogren inside each almond.

Much larger in scale, alfalfa is also exported, often to Asia. "The water used to irrigate just alfalfa and hay — 7 trillion gallons per year — exceeds the irrigation needs of all the vegetables, berries, and fruit orchards combined." (Center for Science in the Public Interest; http://www.cspinet.org/EatingGreen/pdf/arguments4.pdf)