I keep looking for something from the past to relate to California's impending water crisis. The following remark from the witty church father Tertullian (160-220AD) stands out in this regard:
"We enter, then, the font once: once are sins washed away, because they ought never to be repeated. But the Jewish Israel bathes daily, because he is daily being defiled." - Tertullian, On Baptism
If I understand this correctly, Christians only need to bathe once, but others need to bathe daily. Clearly this is something the California government should keep in mind as it looks for ways to conserve water.