Drought-stricken California is preparing to raise the ante on water conservation.

Starting in April, households may be limited to two days a week of outdoor watering. Restaurants might be barred from serving water unless a customer requests a glass. And hotels could have to get approval from guests before washing their towels.

The constraints, which would carry fines of up to $500 per violation, are part of a broader crackdown on water use that state officials are proposing as California faces a likely fourth year of drought.

While the new conservation measures are seen as common-sense practices — steps that many people are already taking voluntarily — state officials say getting everyone on board will go a long way to stretching the state's diminished water supplies.

The proposal builds upon temporary restrictions enacted last summer, which target outdoor watering, and are set to expire April 25.

The State Water Resources Control Board will vote Tuesday on whether to enact the new, broader rules for another 270-day emergency period. But state officials say they will eventually go a step further and consider making the mandates permanent.

"What we're experiencing now, while draconian and maybe the worst we've ever had … may not be as abnormal as we see it today," said Frances Spivy-Weber, a member of the board's governing council. "It's time to be thinking about what we should be doing in a climate-change California."

Many California homes and businesses appear ready to conserve for the long haul.

At hotels in San Francisco and elsewhere, door hangers increasingly advise guests that they can save water by hanging their towels after they use them — a signal that no laundering is needed.

And at restaurants, the question of "still or sparkling?" has become common for gauging whether customers really need a glass of water.

"We just like to check with our guests and see what they want," said Miles Palliser, owner of San Francisco's Corner Store restaurant, where water is served upon request.

"It's going to save not only the environment but the water bill," he said.

As for outdoor watering, the proposed rules would tighten the restrictions adopted in July. Those included bans on spraying sidewalks and driveways, watering lawns or gardens to the point of causing runoff, washing cars without a shut-off nozzle, and using drinking water in ornamental fountains.

Year-over-year water use in California fell about 10 percent during the final seven months of last year. The reduction was short of the 20 percent cut that Gov. Jerry Brown hoped for when he declared a drought emergency in early 2014.