I don't know what you mean by "feasible". Saudi Arabia neither has the population (28mil vs 38mil) of California nor the Farming needs (I don't have numbers on Saudi farms but i'll guess its somewhere near zero).
There are a number of desalination plants along the coast of California and a few more scheduled to be built. However they're very expensive to build and to operate and their yield isn't where it should be.
Supplying 50% of Cali's water via desalination is not at all feasible
There are a number of desalination plants along the coast of California and a few more scheduled to be built. However they're very expensive to build and to operate and their yield isn't where it should be.
Supplying 50% of Cali's water via desalination is not at all feasible