Owners of thirsty lawns, beware. The water cops are here.

"Who ya gonna call?"

The famous buzz phrase from the 1984 movie, "Ghostbusters" is being heard on the lips of Los Angeles water officials grappling with two of the driest years in the city's history.

Their answer: "drought busters."

The program, which helped cut water use by about 30 percent during a drought in the 1990s, comes as the entire state takes step to conserve water.

A federal judge has told state water authorities to cut up to 30 percent of their usual deliveries, starting next month, to protect endangered fish. Last week, the Metropolitan Water District of Southern California announced it was buying water from farmers in the state's Central Valley. San Diego has announced a similar deal with farmers in the Imperial Valley. Hundreds of farmers are idling fields, and manufacturers such as silicon-chip makers are rethinking water processes.

And then there's Richard Crossley and his 15 colleagues. Each "water cop" drives a white Toyota Prius (complete with "Drought buster" logo) and wields a polite smile, handshake, and an armload of bulging information packets.

"Hi, I'm with the Department of Water and Power, and as I was driving by, I noticed a lot of overspray into the street," says Mr. Crossley to Margarita Rojas, a housekeeper who answers the door of a house on Norton Avenue. The sidewalk in front of the house is soaked, and a two-inch-deep puddle of water has gathered.

"Maybe you can inform the gardener to taper down those sprinkler heads," says Crossley gently, as he hands Ms. Rojas a packet of pamphlets.

The pamphlets include water-saving tips, from fixing leaky faucets ("saves 20 gallons a day") to using a broom instead of a hose to sweep driveways (150 gallons). But one also makes clear that L.A.'s Prohibited Water Use Ordinance – in force since the early 1990s – forbids watering lawns between 11 a.m. and 3 p.m. from October through March and prohibits excess water from sprinklers from flooding streets and sidewalks.

"Water conservation is something that Los Angeles has learned to take seriously because of these kinds of educational programs of the past," says Los Angeles Mayor Antonio Villaraigosa. "The most important element is simply making sure people know what is at stake."

Less than 4 inches of rain fell in downtown L.A. during the 2006-07 rain year, down from an average of 15 inches. But for now, Crossley and his colleagues are not issuing formal citations. "We don't want to be real hard on anyone," says Crossley. "Many ... people who waste water ... have moved to Los Angeles in recent years and don't even know the city is in the middle of a desert."

With the current drought affecting California, Nevada, Utah, and Arizona, more cities are going to be employing drought-buster-type operations, creating ranks of formal and informal water cops, experts say.

Florida, which was grappling with its own drought, is another example. Water-management districts in south Florida instituted the toughest usage restrictions in history last spring, allowing lawn irrigation or car washing only during certain narrowly defined times. Special water cops were employed to issue citations to those who disobeyed.

In Los Angeles, Crossley says nearly everyone he talks to is amenable to his suggestions. Once warned, most offenders mend their ways.

Homeowners, gardeners, and other neighborhood workers say the first-time warning is a useful – and appreciated – tactic.

"If you don't give them a warning, they won't do anything at all," says Art Guevara as he carries bricks onto one property. "Then if they keep doing it, you can slap them with a fine and that will make it stick."

In the upscale Hancock Park neighborhood, it's not the homeowners who must be informed, but the gardeners, says homeowner Jack Mansour. "I hate to say it, but most of the residents here don't even know how to work their sprinklers," says the financial analyst.

The main reason Los Angeles has stuck to the educational approach over strict enforcement, say officials, is that it has worked. Since the six-year drought in the early '90s, the city has added 1 million residents but managed to keep water use to 1990s levels.

Besides admonishing residents to conserve, at the time the city gave rebates on low-flush toilets and low-flow showerheads. This year, the city is offering similar incentives, including $150 rebates on water brooms that restaurants and other businesses can use to clean parking lots and sidewalks.

"Conservation and education programs like Los Angeles are a good first step in crisis. They are a very cost-effective way to save water," says Richard Golb, former president of the Northern California Water Association, now an Oregon consultant. "As populations grow, aging water-delivery systems continue to deteriorate, and drought conditions persist, one of the best, first lines of defense is to get a bunch of guys in pickup trucks out to see who is wasting water on lawns and tell them to stop."

• Alison Tully in Los Angeles contributed to this report.