i think the 'canteen' thing is just a translation issue, not literally referring to anything that holds water. looking at it in context, i interpreted it to mean restaurants, diners, taverns, nightclubs, etc. i think if they meant reservoir or any other body of water, they would have just stated it that way.
However, since this is their "spectacular" hitting- wouldn't they want the biggest bang for the buck? Isn't there a reservoir in the West (and underground water) which supplies almost all of Southern California's water supply?