I've not commented on this thread, mostly because I'm conflicted - I feel Muir's outrage, but have enjoyed the Hetch as it stands, a lot.
I did lead a Sierra Club National outing along with the principals of Restore Hetch Hetchy in 2000, through the Grand Canyon of the Tolumne. Wonderful!
I don't know how prone this lake is to silting, but given time, all impoundments will be rendered useless. Then you have millions of tons of stuff to clean up.
Secondly, as the downstream beneficiaries have taken this gift from the People of the Country, they should be required to collect some slice of money from the water bills & use that to help remediate water problems in other National Park areas. Cape Cod comes to mind. And yes, I am aware that SF does kick back about $5 million a year to Yosemite. That's nowhere near the benefits SF has been enjoying for nearly a century.
Verum audaces non gerunt indusia alba. - Ipsi dixit MCMLXXII