[ghshephard]

That's an "average" - it varies quite a bit. San Francisco uses around 100 Gallons/Day.

Things like toilets/showers/washing machines are the major indoor elements for high water consumption, California is starting to adopt all of the technologies that Australia has pioneered for decades - things like low flush toilets, low volume showers, low flow faucets, etc... But it will take time (and money) to update the infrastructure.

Also, much of the water use comes from outdoor use - a lot of green lawns in California that are going to have to go away. Also, leaks are a major components.

In order to get to 100 Gallons/day, people are going to have to give up their lawns. And stop filling their swimming pools.

There is zero chance, outside of a major disaster like an earthquake, that Californians would ever use "65-75 liters/day/person" - that's 17 gallons/day/person. You'd see broad deployments of solar powered desalination plants first.