[doh]

If you're looking at it this way, that every single stream is managed, then yes, you're right. I rather think that we develop only the water sources that make the most sense and leave the rest be.

This way we could talk about the incredible amounts of gold that is diluted in oceans that we could harvest "anytime" [0]. It's around 21x more than humans mined in the whole history.

[0] http://oceanservice.noaa.gov/facts/gold.html