When you consider that at least 3 large metropolitan areas - Las Vegas, Salt Lake and the Los Angeles megalopolis depend in part on this area for their water supply makes you scratch your head.
I'm sure scratchin mine. I was pretty sure that LA water comes from the Eastern Sierra, and Vegas with a population about 1/20th of LA, from the Colorado River i.e. central Rockies. Salt Lake, which is about 1/50th the population of LA County, gets its water largely from the Wasatch. None of these sources are in the Great Basin.
SoCal also imports a large amount of their water supply from the State Water Project and also from the Colorado River as well as the Eastern Sierra. California was buying up Nevada and Arizona water allotments for decades, but recently they are started to demand their full amount, which is forcing a reduction in supply for SoCal from the Colorado. The State Water Project has been delivering a fraction of the capacity because of environmental restrictions in the Delta, which greatly restricts when they can pump. And the LA Aqueduct is having to put water back into Owen's Lake (a huge dust bowl). So the squeeze is on for SoCal and they are spending a lot of money mitigating these impacts just to have supply reliability. Of course they will also support conservation to reduce demand and all the local resources that make sense.
Perhaps Kevin is referring to the transport of the water where aqueducts flow through the Great Basin, rather than the source of the water. In that regard, the Great Basin, and Central Valley are important players. The watersheds for these large projects are of course mountainous terrain, but the transport regions are also important from a system perspective.
