Most of this production would not be possible without irrigation. In average year [sic] California agriculture irrigates 9.6 million acres using roughly 34 million acre-feet of water of the 43 million acre-feet diverted from surface waters or pumped from groundwater.The math here is 34/43=79%. Nearly four-fifths of the "diverted" water in California goes to agriculture.
The above figure of 79% does not include water already flowing on arable land (therefore, the true consumption by agriculture is still hidden from me) , but it's sufficient for the point I wish to make. Agriculture is using about 4/5ths of the water that is being diverted. Cities, industrial and other commercial applications use the other fifth. Shall I guess that urban use accounts for the whole 21%? I'm guessing it's 2/3 of that at most, so urban consumption is perhaps (perhaps!) 15% of all diverted water. If urban usage is reduced 20%, overall usage drops 3%.
36 million people are being asked to make a rather large shift in their behavior for a net savings system wide of 3%. I'm all for people using resources more wisely. I wonder if this is the best place to apply ourselves?
Surely, surely, a far better use of our willpower and effort would be to understand how to use less water agriculturally?