The key form CA is not to replace all water sources, but rather close the gap between rainfall and water needs. Right now, we are doing this by pumping ancient water from aquifers, but as solar power and desalination techs mature, the price will come down and will likely be sufficient to cover that gap. The recycled water will also factor in.
There is a considerable interest in California re: what Israel has done to conserve and increase its water supply. Israeli technology is likely applicable to California's water supply issues and cooperative ventures should be fruitful.
The key form CA is not to replace all water sources, but rather close the gap between rainfall and water needs. Right now, we are doing this by pumping ancient water from aquifers, but as solar power and desalination techs mature, the price will come down and will likely be sufficient to cover that gap. The recycled water will also factor in.