It is now illegal for Californians to use a hose to wash a car without a shut-off nozzle or to hose down a driveway or sidewalk. Obey the rules for 270 days or face fines up to $500 per violation.

These and other unprecedented new restrictions on outdoor water use were approved by the State Water Resources Control Board on a 4-0 vote on July 15 and formally took effect on Tuesday. They apply to both residents and businesses.

The regulations also forbid adding water to decorative water features unless the water recirculates, and to the watering of outdoor landscapes if excess runoff results. The rules come half a year after California Governor Jerry Brown's January declaration of a state of emergency in what may become the most populous US state's worst drought in centuries.

Although the state's government emphasizes the importance of conserving water, and Governor Brown set a goal of cutting water consumption by 20 percent, a new state survey showed that Californians actually increased their water use by 1 percent during the drought.

"People just did not realize how bad the drought is. Although the government has advocated that we should conserve water all the time, people just seem to ignore it. They overuse the water and leave the sprinklers on for the whole day," said Frank Garcetti, a resident of Alhambra.

In some parts of California, 50 percent or more of the water used goes onto lawns and other outdoor landscaping, state officials say.

The State Water Resources Control Board believes conservation steps are crucial, as what is now a three-year drought shows no sign of a bating.

In response to the first-ever state mandatory water restrictions, many cities, including Santa Monica, Pasadena and Alhambra, applied the corresponding actions and required residents to follow the new rules.