Perhaps I should have said "the statement about Hetch Hetchy is true", but it begs the question.
It's easier, cheaper and safer to build dams across narrow canyons with solid rock than in flat land and dirt. And you can grow stuff in the dirt to harvest and sell. Also, the higher you build the reservoir, the wider the range you can deliver water to via gravity. Who would care about drowning some unproductive rock anyway?
Dale B. Dalrymple
