SACRAMENTO, Calif. - Steve Upton thinks of himself more as an "Officer Friendly" than a water cop.

On a recent sunny day, the water-waste inspector rolled through a quiet Sacramento neighborhood in his white pickup truck after a tipster tattled on people watering their lawns on prohibited days. He approached two culprits. Rather than slapping them with fines, he offered to change the settings on their sprinkler systems.

"I don't want to crack down on them and be their Big Brother," said Upton, who works for the water conservation unit of Sacramento's utilities department. "People don't waste water on purpose. They don't know they are wasting water."

At least 45 water agencies throughout California, including Sacramento, are imposing and enforcing mandatory restrictions on water use as their supplies run dangerously low. Sacramento is one of the few bigger agencies actively patrolling streets for violators and encouraging neighbors to report waste.

They teach residents to avoid hosing down driveways, overwatering lawns, or filling swimming pools. While gentle reminders are preferred, citations and fines can follow for repeat offenders.

"We do have the stick if people don't get it," said Kim Loeb, conservation manager in Visalia, a city of 120,000 that has hired a part-time worker for night patrols and reduced the number of warnings from two to one before issuing $100 fines.

Mandatory restrictions aren't as widespread as in previous droughts. One reason is more cities are conserving and making it expensive for residents to guzzle water.

Sacramento, where about half the homes are unmetered, is deploying the state's most aggressive water patrols to compensate. In February, the city of 475,000 deputized 40 employees who drive regularly for their jobs, such as building inspectors and meter readers, to report and respond to water waste.

Providing a boost to their efforts is a campaign asking residents to report neighbors and local businesses breaking the rules. In the first three months of this year, Sacramento has received 3,245 water waste complaints, compared with 183 in the same period last year.

Despite steady rain and snow in February and part of March, the state's water supply and mountain snowpack remain perilously low, meaning there will be far less water to release to farms and cities in the months ahead.