In the fourth year of the most severe drought in state history, Californians are finally starting to turn away from arcane rules and practices that have allowed them nearly unlimited use of water since the era of the Gold Rush.

This week, a group of farmers who enjoyed a riparian right to as much water as they needed from the San Joaquin River sought to strike a bargain with state officials: They would voluntarily cut the amount they use by 25 percent in exchange for keeping the remaining 75 percent for irrigation, even as the drought continues.

The director of the State Water Resources Control Board is expected to decide Friday whether to accept the proposal.

Meanwhile, the city of Sacramento, which for decades resisted a basic step to conserve water — putting meters on homes to measure use — is scrambling to finish a $390 million project to install them at every home and business. The city also draws water from the Sacramento-San Joaquin River Delta.

The delta is so dry that young chinook salmon die trying to migrate 90 miles from the San Joaquin River in the Sacramento area to the San Francisco Bay. State officials are in the middle of an effort to truck 30 million of them to the bay from several hatcheries in a dozen 35,000-gallon water tankers. The hatcheries would normally release the young fish in the San Joaquin basin, but the water in some places has dried up; in others, it is too warm and shallow.

Sacramento’s dated infrastructure — and thinking, some critics say — is emblematic of the challenges California faces in its push to carry out the order by Gov. Jerry Brown (D) to cut statewide water use by 25 percent.

The Golden State has been lax about its water use since it was founded in the mid-1800s, experts said. State lawmakers passed legislation requiring all cities to gradually install water meters just a decade ago, and only last year took steps to start measuring the amount of groundwater taken by homeowners, ranchers and farmers. Few states still have such a hands-off approach to pulling water from the earth.

“We have a 21st-century water problem with 19th-century infrastructure, and . . . hundred-year-old water laws and water rights allocation,” said Peter Gleick, president and co-founder of the Pacific Institute, a nonprofit research and policy group based in Oakland.

Across the state, a quarter of a million homes still lack meters, many in the dry Central Valley, Gleick said. Occupants of those homes pay a flat monthly fee for water — or nothing at all, in a few cases — because there’s no way to track how much they use, he said.

“It’s a historical artifact of when we had plenty of water, the way the state developed,” Gleick said. “Even with this waste, even with this inefficient system . . . everybody got the water they wanted. That’s no longer true.”

Sacramento stands out because the city barred meter installation — not wanting to raise water rates — until the state overrode the legislation in 2004. Today, more than 60,000 homes and businesses there lack water meters, the most non-metered properties of any city in the state. City officials hope to add 16,000 meters by 2016 to the 74,000 it installed over the last 10 years.

The rules adopted recently by the State Water Control Board require the state’s 411 water providers to cut use by varying amounts, depending on how aggressively they conserved water in previous years.

Sacramento-area utilities were among the hardest hit. The Sacramento County Water Agency must cut its output by 32 percent — about 1.5 billion gallons — compared with 2013. The city of Sacramento is required to reduce its water use by 28 percent. By contrast, conservation-minded San Francisco faces an eight-percent cut.

The state is using a carrot-and-stick approach. Brown promised to help agencies provide rebates to customers who replace leaky devices such as shower heads and toilets with newer water-efficient models.

But the agencies are also being threatened with a $10,000 monthly fine if they fall short of conservation goals, a cost that can be passed on to ratepayers who guzzle water.

Fines of up to $500 per day can be issued to homeowners by a police officer or public employee authorized to give a ticket. Some water suppliers hire enforcement authorities to seek out violators.

The task got even more complicated in April when a utility in the Orange County area lost a court appeal over how it charges residents who use the most water.

A group of taxpayers complained that the tier rate, which tacked on progressively higher costs for every 750 gallons of water used per household, for the city of San Juan Capistrano — located between Los Angeles and San Diego — violated state law.

Proposition 218 requires agencies to calculate the actual cost of delivering more water in added costs to ratepayers.

“The water agency here did not try to calculate the cost of actually providing water at its various tier levels,” a California appeals court wrote in its ruling. “It merely allocated all its costs among the price tier levels, based not on costs, but on pre-determined usage budgets.”

Utility operators in other areas are concerned because many of them use a similar tier-rate system.

“I’ve probably received at least 20 phone calls and e-mails from taxpayer groups,” said Ben Benumof, the lawyer who represented a group of ratepayers. “The many that we’ve looked at to date appear to be arbitrary as well, not tied to costs” of providing water.

“These tier systems might be more equitable if they are based on the size of your family or the size of your property,” he said.

Beverly Hills faces a special problem because while it only has 36,000 residents, its population swells each weekday with 170,000 workers and visitors. As a result, the city’s peak use last summer was 280 gallons a day per person. Compare that with the 160 gallons used in Sacramento and the 90 gallons in Los Angeles.

As a result, Beverly Hills was ordered to cut output by 36 percent, compared with 2013.

“Physically, it’s just going to be hard to do,” said Robert Wunderlich, who represents Beverly Hills on the Metropolitan Water District of Southern California. “Let’s say you reduce outdoor water use by a third; you still have to save 11 percent of your water usage.”

When water agencies use up their allotted amount of water, they have to request more, Wunderlich said. The water district has to scramble to find that water, and agencies pay.

“Those last gallons cost more than the first,” he said. “If the cities themselves were out scrambling, it would be easier for them to justify the cost.”

As the state grew more serious about water conservation, Sacramento decided to rush to complete its meter installation project five years earlier than the original deadline of 2025.

Hopefully, Wunderlich said, the drought is a wake-up call to all Californians.

“This has the possibility of being one of those moments you get that critical mass of attention and people’s behavior really starts to change,” he said. “There might be a lifestyle change in California that’s more consistent with the area that we live and our available resources.

“Fifteen years from now, people might look back and say, ‘Isn’t it odd that we used to do things that way?’ ”