Most of southern California is a desert. Los Angeles could not exist if water was not brought in to it.
California is no more uninhabitable because of it's terrain then any other parts of this nation. We have technology and know how to build anywhere.
As for "protected" environment, these area became protected by law and can be unprotected by law.
The only thing that restrains California from being a great state again is the strangle hold the socialist (with support of unions and government workers) have on it.
The Democrats have created the mess and it will not be fixed until they are out of power.
There is one thing that makes life possible in most modern, densely populated cities anywhere, not just LA. And it is this: the availability of affordable energy in quantity and on demand. Take that away and you have little or no water, no sanitation (disease would sweep through the population like wildfire), no ability to move goods (i.e., foodstuffs), no ability to allow people to move freely about and engage in commerce. There simply isn't enough in the natural environment of most cities to sustain even a sizable fraction of the population at even a minimum standard of living. Most people in cities today would simply die in their homes if energy in the quantities needed were not available.
Which is why I find it ironic that people in NY agitate for the shutdown of Indian Point, or people in LA go on the warpath against places like the San Onfre power plant. Those are the very things sustaining their lives, yet they want to get rid of them. They are cutting their own throats, as well as those of millions of their neighbors.