[B Knotts]

You could do some in the Temecula/Hemet area...wouldn’t be too hard to get seawater over there. Maybe the Imperial valley, too.

Also, there are some areas of central California that might work.

[count-your-change]

An open pond, and that's the method that the large scale projects companies like PetroSun are planning on, would loose lots of water by evaporation so let's say that each acre lost a foot of water each year. To replace that foot of water would require about 326,000 gallons.
Having lived in the desert I can say a shallow pond could lose a foot of water in a week or less, let alone per year.
And several millions of gallons of sea water per day will get there by what pipeline? and what system of pumps to push that water 1500 ft. above sea level.
Of course if the finished product can be sold at +$25/gal. it has promise.