Actually Los Angeles has more space to grow in the great Mojave Desert, beyond Palmdale and Victerville heading towards Barstow and California City.
The only problem is...how to get people from the northern basin into the LA basin.
Hmmm.... maybe a few tunnels under the San Gabrial Mountains?
The cost? Probably in tens of Billions? But its definatly worth it.
Think about it....both California City and the L.A. area at last truly joined.