Farmers are planting almonds because, as permanent crops, they do not need to be replanted after every harvest. They have been steadily taking over from cotton and lettuce because they are more lucrative. “That’s the highest and best use of the land,” said Ryan Metzler, 45, who grows almonds near Fresno.

The problem is that not only do almonds and pistachios, another newly popular nut, need more water, but the farmers choosing permanent crops cannot fallow them in a dry year without losing years of investment.

Now the state is putting new controls on the groundwater that has gotten many farmers through the brutal drought — which still looms over the state, despite recent rains — and there is no certainty that the future of almond and pistachio orchards in areas like the western San Joaquin Valley is secure.

So almond growers are determined to be granted the water they need to keep their crops from dying, particularly in the Westlands Water District in the San Joaquin Valley, where 15 percent of the fields are covered with almond trees, up from 5 percent about 15 years ago. They chafe at the rise in the 1990s of environmental restrictions designed to help the survival of salmon species threatened by two generations of water diversions.

“We’ve had 20 years of a regulatory approach that has not improved the fishery,” said Jason Peltier, the chief deputy general manager of the Westlands Water District, which serves some of the richest growers in the state. “The reality is that their regulatory methods have failed on every measure” of the health of salmon species. His hope for the next Congress is that “they will take a look at the social and economic damage that the regulatory environment has created”