Don't get the idea that I believe that Arrowhead Mountain Springs water comes from Lake Arrowhead (although my tap water comes from there). I just use that as an example and it's usually on sale at the local market. The original Arrowhead springs water comes from springs in the foothills of San Bernardino, below the rock formation that gives the Lake its name.
Interesting history on all that; Los Angeles won all water rights way back when and a man doesn't even own the spring on his own property anymore.