Los Angeles ? The green thumbs who keep lawns lush and flora flourishing in the city have found a new foe among the aphids, white flies and other yard pests — the water police.

Just as some scofflaws keep an eye out for black-and-white patrol cars, gardeners have learned to spot the white Toyota Priuses driven by Los Angeles water cops out to fight waste as California struggles with an extended drought.

“They get to scattering when they see us,” said Department of Water and Power officer Alonzo Ballengar. “I don’t know what they call me, but I’m sure they have names.”

Fifteen officers now prowl neighborhoods and respond to thousands of tips in their search for those who use sprinklers between 9 a.m. and 4 p.m., clean driveways with water instead of a broom or otherwise waste the precious commodity.

Officials estimate landscaping accounts for as much as 70 percent of household water bills.

Offenders can be cited with a warning or hit with fines that start at $100 for homeowners and automatically appear on water bills.

The tough tactics began this summer after a voluntary conservation program yielded only a 4 percent drop in water use. Restrictions were expanded and penalties stiffened with the aim of seeing a 10 percent reduction.

Thus far, 763 citations have been issued.

The threat of a water shortage is deadly serious in this sprawling, thirsty city that owes its existence to the vast quantities of water piped in from the Colorado River and other sources.

In June, Gov. Arnold Schwarzenegger declared a statewide drought in response to two years of below-average rainfall, low snow-melt runoff, shrinking reservoir levels and court-ordered water restrictions to protect diminishing fish populations.

But getting the conservation message to sink in has been a challenge in the city where expansive lawns and tropical gardens have long been status symbols.

City officials first unveiled the “drought busters” patrol in the early 1990s. Their blue T-shirts and patches with images of crossed-out drippy faucets were reminiscent of the “Ghost Busters” movie logo.

Now, to be taken more seriously, the unit has been outfitted with gray uniforms and renamed the water conservation team. There are similar programs in some other U.S. cities.

“They’re in fact educators and ambassadors to the public,” said H. David Nahai, who renamed the team and oversees the agency. “They deserve to have a title that is reflective of the gravity of the situation.”

Not even the governor, who has urged Californians to save water, is safe from scrutiny. On a recent afternoon Ballengar drove past split rail fences and horse barns into the gates of the upscale community where Schwarzenegger lives in the Brentwood area.

Ballengar stopped for a moment in front of the governor’s mansion, peering through the iron gate searching for any evidence of water waste in the governor’s garden.

“Nothing,” he said before driving on.