LOS ANGELES -- California's worst drought in 60 years has cut water use in so many neighborhoods that officials have begun to fear a new political war between grimy suburbanites, irritated by brown lawns and short showers, and the agricultural industry, which uses more than 80 percent of available water.

In a period of rapidly changing attitudes toward water's role in the Southwest's economic and population boom, some urban politicians are demanding cuts in agricultural use. Southern California's leading water agency has signed a landmark agreement to pay for conservation measures in one farming district and send water saved to urban customers.

"If all the urban areas and all the business areas cut water use by 25 percent, it would be equal to agriculture cutting use by only 3 percent," said Assemblyman Phillip Isenberg (D-Sacramento), advocating an urban uprising against rural water waste.

"This may be one of the few issues in life where, if the public understood that simple fact, the dynamics of the situation would radically change."

Such talk enrages and sometimes frightens farmers and professional water managers who see California's $16 billion annual agricultural production as proof of the wisdom of multibillion-dollar water projects that have turned deserts such as the Imperial Valley into huge fruit and vegetable gardens.

Lois Krieger is chairman, as her father was, of southern California's principal water agency, the Metropolitan Water District (MWD). She said she sees "tremendous potential" for demagoguery in arousing urban residents against farmers. "There are people who, if it is possible to divide the state politically on this, would be most happy to do so."

The MWD has moved to ease the pressure by signing a $220 million conservation agreement with the Imperial Irrigation District, responsible for the now-fertile desert valley near the Mexican border.

The MWD agreed to finance new flow-regulating reservoirs and improved canal lining, and provide more flow monitors, in return for the 106,000 acre-feet of water that would be saved annually. That is enough to meet residential water needs of more than 200,000 families.

Water managers throughout the state have applauded the agreement. Some expressed fear that, without such measures, water-short cities in the future may be forced to buy up farmland for water allotments, reducing the crop acreage and sending food prices up.

Bob L. Vice, president of the 85,000-member California Farm Bureau Federation, said growers are conserving water. "Every year, we have more places using low-flow and drip irrigation," he said. Federal water price subsidies are about to expire in many parts of the San Joaquin Valley and farmers such as Vice, who pays 10 times the average California water price to irrigate his citrus and avacado ranch near San Diego, said they cannot profit unless they conserve.

Many urban and suburban skeptics remain. "Irrigated pasture land has very little value," said Tim Brick, an MWD board member who lives in thickly populated Pasadena, "yet we use as much water for pasture land as we use in the homes of all the people in the state."

Few experts have expressed doubt about the seriousness of the current drought, although its full impact has yet to be felt in southern California because water remains in MWD's many reservoirs.

A spokesman for the state drought center said that, with the rainy season ended, the state has received only 65 percent of average precipitation, making this the driest of the four consecutive drought years. Already 400 local water agencies have imposed restrictions, and more are expected if abundant rain and snow do not come this fall and winter.

Water allotments to agriculture from the state aqueduct have been reduced severely, but many can make up the difference by pumping more ground water at higher cost.

Hardest-hit residential areas have been first to complain that agriculture is hogging the water. In Santa Barbara, where some homeowners are having their dry lawns painted green, a Santa Barbara News-Press editorial called for more water restrictions on local farms, saying:

"It is simply in the best interests of the entire county -- and therefore incumbent upon the board of supervisors to insist -- that farmers and ranchers come under the same scrutiny as do the rest of the county's water consumers."

Isenberg, representing northern Californians, forecast a healing of the longtime north-south split on water issues. In an article in the San Diego Union, he told southern California readers that he would not mount the usual northern attack on southerners "for taking water from the north only to wash {their} cars, hose down {their} sidewalks and fill {their} swimming pools" because "I know better: Very little of the water that's diverted from the north ends up in southern California; most goes to agriculture in the San Joaquin Valley."

He went on to recite provocative statistics from Marc Reisner, author of the book "Cadillac Desert." "Alfalfa . . . uses the same amount of water that is used by all of the people in both the Los Angeles area and the San Francisco Bay area," Isenberg said. "Two other crops, cotton and rice, use enough water for 25 million people," more than 80 percent of the state's population.

To water officials who have spent their careers helping agriculture to grow, such reasoning ignores the intermingling of residential and farm interests. "They sit there wearing a cotton shirt and complain about agriculture using all the water," said Cliff Trotter, engineer-manager of the Arvin-Edison Water Storage District in the San Joaquin Valley.

Many farmers and water managers want the state to spend more on reservoirs and pumps to capture and divert the northern California runoff that still flows unused into the ocean.

But to do that, many acknowledge, they must convince skeptical city dwellers that they have not wasted what they have. "Conservation has to become our lifestyle in this state," Krieger said.