Hetch hetchy dam and John Muir.?

I was wondering if the damn could be built anywhere else. I am writing as if i am John Muir and so i need to defend the building of the dam. THe only problem is so far is that i cannot find another place that the dam for San Fran could have. Also if you know anything that John Muir did to help conserve land out of the country and that he was just a man of california, or even a man of the north west that would be helpful as well.