Furthermore, this won't "restore Hetch Hetchy Valley to its former natural splendor."
The valley is forever changed, and will be very different than it was before the dam was put in.
What's done is done. People should consider getting a life instead of wringing their hands over what was done years ago.
The regulators in Washington State are requiring folks who mitigate development restore land to "Pre-Colombian" conditions. And they tell you with the most serious straight face. Bizarre.