I thought it was because it hasn’t rained much.
Common sense tells us to cut back on the programs that send water to the sea. Political and “feel good” nonsense says that we must protect a bait fish even if the effect on people is negative. I have said before that sending many illegal immigrants back to Mexico would lessen the demand for water.
In that context it was about floating thousands of black plastic balls on a reservoir to slow evaporation at the cost of $34,000,000 was a waste. Guess what? The State of California is now collecting those black balls. Seems that there was a unforseen problem with the chemistry of Sun, Water and Plastic. SHEESH!!!!!!!!!
All of this is true except the conclusion. The 20th Century happened to be the wettest century in the past few thousand years for California and the Southwest. Normal centuries in that same period saw an average of only 2/3 the amount of wet we got in the 20th Century. Worse, centuries-long mega-droughts in the same period produced an average of only 1/3 the average yearly precipitation of the 20th Century. For California and the whole Southwestern US.
The place happens to be something called "desert". There is a reason for that.
Environmentalists blame everything they don't like on the presence of nasty human beings. Regretably a fair number of right-wingers do too. They think real life is a conspiracy.
S### happens.