Ban lawns, or at least watering them. Increase the use of aquifers and natural water reserves on site.
A difference which almost goes back to the topic of the NG article.
If you reduced all consumer usage of water to zero, it would barely make a dent.
California can solve its consumer water problems with a couple of desalinization plants. Farming in the Central Valley, however, would basically need to be shut down to stop draining the aquifers.
This is equivalent to the "we have to convert to electric cars because of climate change!" which will also barely make a dent in carbon emissions (unlike, say, converting the world to nuclear power plants).
That said, replacing long distance haul with electrified rail transport would be yet better.
Even if electric cars were carbon-equivalent, moving a million point sources of pollution (internal combustion engines) to a single point source of pollution (a power plant) is way better for us all.
From the article:
California has 11 desalination plants, and another 10 are being planned