When it comes to wasting water amid historic drought, Californians are good at pointing fingers.

Last month, criticism was showered on Hollywood’s elite, including Sylvester Stallone, Kim Kardashian and Kevin Hart, who were accused of using water excessively. Some celebrity households consumed thousands of gallons of water per day during particularly dry times, bolstering Southern California’s reputation for recklessly indulging in big lawns, pools and shiny, clean cars.

But given the bad rap that Southern California gets, is the Bay Area really that much better at stewarding its water? Well, it depends on how you look at the issue.

Residents of the Bay Area have historically been among the best in the state at conservation. This year is no different. From January to July, the nine-county region averaged 66 gallons of water per person, per day, compared with the state average of 86 gallons, according to state data reviewed by The Chronicle.

San Francisco residents used just 39 gallons per person, per day, the data show. That’s basically not much more than a shower, several toilet flushes, maybe running a water-efficient appliance for dishwashing or laundry and — crucially — little or no outdoor watering. As the second-most-densely populated city in the U.S., San Francisco has little space for water-hungry lawns.

Northern California, including the foggy Bay Area, also benefits from more rain relative to Southern California, which means that lawns down south need more water to stay green.

Top of story: The Oaks neighborhood in Calabasas (Los Angeles County).

Above: Don Pedro Reservoir in Jamestown (Tuolumne County).

But where the Bay Area tends to lag other parts of the state, experts say, is in developing and diversifying where it gets its water. The region’s large water suppliers, including the San Francisco Public Utilities Commission, often rely almost entirely on runoff from rain and snow, and sometimes from few places, making communities particularly vulnerable to dry spells.

Cities such as Los Angeles and San Diego, while they might wield a heavier hand at the tap, have worked to broaden their supplies so they have more water during droughts. Some utilities along the state’s southern coast get significant water from desalination, recycling and underground.

“The Bay Area could learn some stuff from Southern California,” said Felicia Marcus, former chair of the State Water Resources Control Board and a visiting fellow at Stanford University’s Water in the West Program. “I know they don’t like to think that.”

Southern California’s assortment of water supplies was born of necessity. The area is generally hotter and drier than coastal spots to the north, forcing it to contend with droughts and water shortages for a long time — something that other parts of the state are realizing they’ll have to do as the climate warms.

“Our region has invested heavily over the past 25 years to get more water,” said Sandra Kerl, general manager of the San Diego County Water Authority, which supplies cities and water agencies serving about 3.3 million people. “Conservation alone won’t get us to where we want to be.”

At a cost of about $1 billion, San Diego County built the nation’s largest seawater desalination plant, which provides 10% of the county’s water. It has also developed several wastewater-treatment projects that have increased recycled water to 6% of its supply. Groundwater, local runoff and a variety of water imports account for the balance.

As a result of the diversification, Kerl said her agency’s water supply remains robust despite three years of drought. Her agency has even expressed opposition to calls for statewide water restrictions, which Gov. Gavin Newsom has threatened to roll out, because residents have already made sacrifices — financially — to prepare themselves.

The Tuolumne River flows downstream from the Hetch Hetchy Reservoir near the Sierra Nevada foothill community of Groveland, Calif., on September 1, 2022.

Park visitors walk across O'Shaughnessy Dam in Yosemite National Park, Calif., on September 1, 2022. The O?•Shaughnessy Dam was completed in 1938 and is 430-feet tall. The 117-billion-gallon Hetch Hetchy reservoir supplies drinking water to about 2.5 million San Francisco Bay Area residents and hydro-electric power generated by two plants downstream.

The Bay Area has weathered droughts largely through conservation, with a big assist from its cooler, wetter weather and sometimes smaller parcel sizes, which reduce demand. In addition, supplies for much of the region are hardy, in spite of the lack of diversity. As a result, there’s been little urgency to seek out new water.

The San Francisco Public Utilities Commission gets about 85% of its supply from three reservoirs in and around Yosemite National Park, including Hetch Hetchy, which have generally produced plentiful supplies for 2.7 million people in the city and its suburbs. The rest of the agency’s water comes mostly from runoff collected at a handful of Bay Area reservoirs, including Crystal Springs in San Mateo County. Only small amounts come from groundwater and recycled water.

The East Bay Municipal Utility District, which serves 1.4 million people in Alameda and Contra Costa counties, gets about 87% of its supply from runoff in the Sierra Nevada’s Mokelumne River watershed and 10% in the East Bay. The balance comes from recycled water. This year, the district also bought extra water from a supplier outside the region.

Smoke from nearby fires creates hazy conditions over the Hetch Hetchy Reservoir in Yosemite National Park, Calif., on September 1, 2022.

A public water supply sign stands near the Hetch Hetchy Reservoir in Yosemite National Park, Calif., on September, 1, 2022.

Bay Area water officials say they’re working to broaden their sourcing.

Many agencies have begun to increase water recycling. A coalition of suppliers that includes the SFPUC and EBMUD is trying to expand Los Vaqueros Reservoir in the East Bay to store more water from the Sacramento-San Joaquin River Delta for regional use. The group is also looking into the possibility of building a shared desalination plant in the delta.

The city of Antioch has shown as much initiative as any Bay Area supplier, recently breaking ground on a small desalination plant in the delta with the hope of procuring 30% of its water there.

Construction continues on enhancements to the Antioch Desalination Plant in Antioch, Calif. Thursday, Sept. 1, 2022.

Construction continues on a new building which will house the reverse osmosis process at the Antioch Desalination Plant in Antioch, Calif. Thursday, Sept. 1, 2022.

However, until these water projects come online, most of the region’s water providers will have to rely on conservation to stretch supplies. Local calls for cutbacks, and in some cases restrictions, have been widely successful.

Over the past 13 months, when many state and local leaders began pushing for austerity, EBMUD customers have reduced water use 16.5%, compared to the baseline year of 2020, according to the most recent state records. San Francisco residents cut back 6.7%.

Over the same period, the Bay Area as a whole has reduced water use by about 9% compared with the baseline year of 2020. Only counties along California’s far northern coast, where the weather is cooler and wetter, logged greater regional savings. The cuts are still not as deep as the 15% reduction that Newsom has asked for — statewide savings have been 3.4% — but state water officials have been pleased that the conservation numbers have generally trended upward this year.

The South Coast, meanwhile, defined as a hydrological region that includes Los Angeles, Orange County and parts of San Diego, Riverside, San Bernardino, Ventura and Santa Barbara counties, trimmed only a little more than 1% since last summer, compared to 2020.

“You have a strong sense of environmental stewardship” in the Bay Area, said John Coté, spokesperson for the San Francisco Public Utilities Commission. “When you add that to the SFPUC’s investment in conservation, you get a residential per capita water use that is among the lowest in the state.”

Park visitors walk across O’Shaughnessy Dam in Yosemite National Park.

Coté noted several programs his agency offers to help customers cut back, including free water-use audits of homes and money for swapping out wasteful appliances and landscapes.

In stark contrast to San Francisco is Southern California’s Las Virgenes Municipal Water District. The district, which includes wealthy enclaves in the San Fernando Valley of Los Angeles County, is where the big water bills of several actors and athletes were made public.

The customers were outed after the district made it illegal to use more than a given amount of water, a quantity tailored to the parcel. The rationing policy is one of few in place in California. Under the district’s regulations, those who exceed 150% of their monthly allowance four times are subject to having a flow restrictor slapped on their water main.

About 2,000 customers, according to the district, have been threatened with the device, which slows faucets to a trickle. More than 70 have gotten them.

A watered lawn not following draught restrictions, right, is neighbored by a lawn with native plants in The Oaks neighborhood in Calabasas, Calif., on Thursday, September 15, 2022.

Cason Gilmer, Senior Field Customer Service Representative with Las Virgenes Municipal Water District, holds a flow restrictor in the meter shop at Las Virgenes Municipal Water District in Calabasas, Calif., on Thursday, September 15, 2022. Gilmer invented the flow restrictors.

“If you’re trying to wash your hair, you’re going to be super aggravated because it takes a long time,” said Mike McNutt, public affairs and communications manager for the district. “But not only is this drought historic, it’s the most dire situation we could possibly be in and for people to disregard what we’re asking them to do, they absolutely deserve a flow restrictor being installed.”

Heather Cooley, director of research at the Pacific Institute, a water think tank in Oakland, says it’s not just the rich and famous in Southern California who are using too much.

“All regions have opportunity for doing more,” she said, adding that the solution is not necessarily cutting back but becoming more efficient.

As conservation-minded as the Bay Area may be, it still has its share of water hogs, especially in wealthier spots. The community of Hillsborough averaged 270 gallons of water per person per day in the month of July, the latest state data shows. The town buys water from the San Francisco Public Utilities Commission.

Atherton, Portola Valley, Woodside and a slice of nearby San Mateo County, all served by the private California Water Service company, did only slightly better, collectively averaging 217 gallons of water per person a day. (The water company also gets most of its water from San Francisco.)

“It’s imperative that we take proactive steps to not only respond to drought,” Cooley said, “but to prepare for a hotter drier future ahead.”

Kurtis Alexander and Yoohyun Jung are San Francisco Chronicle staff writers. Email: kalexander@sfchronicle.com, yoohyun.jung@sfchronicle.com Twitter: @kurtisalexander, @yoohyun_jung

Kurtis Alexander is an enterprise reporter for The San Francisco Chronicle, with a focus on natural resources and the environment. He frequently writes about water, wildfire, climate and the American West. His recent work has examined the impacts of drought, threats to public lands and wildlife, and the nation's widening rural-urban divide.

Before joining the Chronicle, Alexander worked as a freelance writer and as a staff reporter for several media organizations, including The Fresno Bee and Bay Area News Group, writing about government, politics and the environment.

Yoohyun Jung is a data reporter for The San Francisco Chronicle. Most recently, she worked as a data journalist for Honolulu Civil Beat, a watchdog news organization covering the Hawaiian islands. Born in Seoul, Yoohyun began her career in Arizona, where she worked for two of the state's largest newspapers covering various beats, including criminal justice and education. She is also an alumna of Reveal from the Center for Investigative Reporting Investigative Fellowship and The New York Times Student Journalism Institute. 

Read more about the data team and their work.