For nearly 50 years, California has passed sweeping environmental laws that limit private property for the common good — from the nation’s toughest automobile pollution standards to curbs on clear-cutting forests to rules requiring that developers keep beaches open to the public.

However, when it comes to preserving one of the state’s most critical and politically divisive resources — billions of gallons of groundwater that are vital to farms and cities — California lawmakers and voters have done almost nothing.

Now, driven by the historic drought and new pressure from Gov. Jerry Brown, the chances of reform appear better than ever.

Decades of intense pumping have dropped water tables dangerously low in places such as the San Joaquin Valley and Paso Robles. Scientific studies show that the ground is sinking in some places and that aquifers are at risk of running dry.

“Some people have had the attitude that our groundwater will be here forever,” said John Garner, who grows rice and walnuts on 600 acres in Glenn County, 80 miles north of Sacramento.

“But now they realize that ‘Holy crow, we could have an impact here and to protect ourselves — although not everybody is there yet — they realize they probably really should start better management.'”

Over the past six months, farmers, environmentalists and urban water districts have been holding workshops, hearings and private meetings in Sacramento to discuss how to preserve the state’s depleted groundwater.

In years past, the Farm Bureau and other powerful agricultural groups fought nearly every attempt at statewide rules.

“Opponents have attacked it as an attack on property rights,” said Lester Snow, former director of the state Department of Water Resources. “But the irony is that you need rules to protect property rights. Today there is a whole different tone in this conversation.”

Now, for the first time, some farm groups are open to discussing measures to require landowners to report the amount of groundwater they pump, probably to local agencies. The rules could require installing meters on some wells and even limiting how much water is taken out of the ground.

Depending on what bills emerge in the Legislature this summer, counties and local water districts also may be given the authority to collect fees, or “pump taxes,” from farmers and other well owners to pay for programs to restore groundwater basins.

Santa Clara County has had a pump tax in place since 1964. Because of farming and population growth, the water table fell 175 feet from 1915 to 1965. Since then, after years of the Santa Clara Valley Water District putting water back underground in wet years, the water table has returned to where it was a century ago.

Statewide, the details are complex. But the basic problem is simple.

California is largely arid. Most of the state, including San Jose, Los Angeles and much of the Central Valley, receives only 15 inches of rain a year on average, the same amount as Casablanca, Morocco. So far this year, those places have received only 4 or 5 inches of rain.

Although reservoirs, creeks and rivers provide the bulk of the state’s drinking and farm irrigation water, groundwater provides 30 percent of the water for farms and cities in most years, and as much as 60 percent in dry years such as this one. When reservoirs run low, farmers and cities furiously pump more water from the ground.

However, in many parts of the state, they don’t put any back. Overall, California pumps out about 2 million more acre-feet a year than is recharged, according to state estimates. That’s enough water for 10 million people a year.

“It is similar to federal budget deficits, except that the government cannot print more water, nor can we borrow it from Chinese banks,” said Jonas Minton, with the Planning and Conservation League, an environmental group in Sacramento.

California uses more groundwater than any other state. Other dry Western states, such as Arizona, New Mexico and Colorado, require property owners to obtain a permit from the state to pump groundwater, and make data on well pumping public as a tool to manage aquifer levels. California does not.

Many California farmers remain wary of any new controls, however.

“For farmers down here, there is a lot of concern,” said Ryan Jacobsen, whose family grows grapes on 640 acres south of Fresno.

“It’s no secret that groundwater is what allows farmers to get through these critically dry years. And when you start talking about what could be some very substantial regulations and restrictions, that’s going to hamper their operations.”

Jacobsen, who is also executive director of the Fresno County Farm Bureau, said that for any rules, local oversight is key, as is building new reservoirs to help store more water.

Ironically, it may be a change in the type of crops grown that could lead to reforms. In many areas, expensive permanent crops, such as almond orchards and wine-grape vineyards, are replacing row crops and pasture land that can be fallowed in dry years.

“It’s in the economic interest of these high-value crops to make sure there is enough groundwater to get through droughts,” said Jay Lund, director of the Center for Watershed Sciences at UC Davis.

With farmers all over the Central Valley spending hundreds of thousands of dollars to drill deeper wells, often competing with their neighbors for the same water, pressure is mounting.

“I have people come up to me all the time and say, ‘You guys have got to do something, just don’t tell anyone I told you that,'” said Felicia Marcus, head of the State Water Resources Control Board.

Paul Rogers covers resources and environmental issues. Contact him at 408-920-5045. Follow him at Twitter.com/PaulRogersSJMN.