As a third parched summer forces farmers to fallow fields and lay off workers, two water districts and a pair of landowners in the heart of the state's farmland are making millions of dollars by auctioning off their private caches.
Nearly 40 others also are seeking to sell their surplus water this year, according to state and federal records.
Economists say it's been decades since the water market has been this hot. In the last five years alone, the price has grown tenfold to as much as $2,200 an acre-foot - enough to cover a football field with a foot of water.
Unlike the previous drought in 2009, the state has been hands-off, letting the market set the price even though severe shortages prompted a statewide drought emergency declaration this year.