What you're referring to is "Los Angeles Against the Mountains," which is one of three works collected in John McPhee's book, The Control of Nature. (That book is a nonfiction classic, the title pointedly ironic, since no one can control nature.)All well and good on flat ground, and with a wad of money. Have you seen the terrain in the west? The brush in the populated areas is growing where houses weren't built, likely due to topography--steep ravines. Then after you take all the vegetation off, what are your plans to maintain slope stability? Not to mention people who will do hand labor. The current labor force is likely to be decimated soon. You got what you wanted on that.
Don't know about how much natural gas CA uses for power. We send them a bit from our dams, and they have some big solar projects in the desert. This would be a good time to add rooftop solar during the rebuilding process. I imagine the power company would not want that option.
There's a book out there somewhere that I read a few years ago. I thought it was by John McPhee, but none of the titles fit and I don't think it was Assembling California. The book goes into detail about the geology of SoCal,,how neighborhoods are built on landslides, areas that have had flash floods, earthquakes, etc. and some of the mitigation measures being tried. Might be a good one for people to read and get an idea of the scope of things. But dammit! I can't remember the title. Maybe it was Assembling California? Or was it the one about attempts to tame nature?
"LA against the mountains" details what happens when fire, which nature occasionally sparks in the Santa Ana mountains, burns the brush clean off those steep slopes & ravines. Then, when rain does come--as it must--the denuded ground is primed for sliding downhill in breathtaking ways. Pretty spooky reading about the guy whose family winds up pinned by landslide mud up to their necks inside their house expecting to die. He was a developer, had built his home like a concrete bunker, knowing the danger of his situation. They survived, but just barely.
To whoever thinks "they just need to do this . . . or that" to prevent environmental disaster around LA--it's worth reading "LA Against the Mountains" to learn the extraordinary measures that have been put in place, for decades now. But no matter what you do, you can't prevent or mitigate against every disaster.