Nearly 4,000 corporations, farms and others hold senior water rights in California, exempting them from government-mandated cuts in water use during the third year of drought. Here is a look at five of them, along with how they obtained the right to draw water from waterways and how they use it:
In a Sierra Nevada hamlet of Moccasin near Yosemite National Park, San Francisco's official seal adorns Art Deco-style buildings facing a hydroelectric plant and reservoir. Though located 140 miles east of the city, the plant is run by its employees.
Tuolumne River water rushes through the plant, creating electricity, then into Moccasin reservoir before being carried by tunnels to San Francisco Bay Area taps.
The city pays just $30,000 annually for the right to use pristine water for drinking and electricity for the airport, schools and firehouses.
The sweet deal is thanks to San Francisco Mayor James Phelan, who in 1902 tacked a handwritten notice on an oak tree over the mighty Tuolumne's Hetch Hetchy Gorge.
That note was all it took in those days to claim the water, and today San Francisco is among the lucky few that enjoy the state's highest-level rights to use of water from rivers and streams. And that's especially valuable during drought, when the state is cutting deliveries to everyone else.
"The system seems cumbersome to a lot of people, and it certainly is,'' said Steven Ritchie, assistant general manager at San Francisco's Public Utilities Commission. "It certainly works for San Francisco.''
On the Upper McCloud River near Mount Shasta sits a rustic estate, perched amid ponderosa pines on 67,000 acres. The gingerbread-style buildings and Julia Morgan-designed main house are Hearst Corp.'s Wyntoon -- the other, less well-known Hearst castle.
The Hearst family claimed water rights on the McCloud in the 1920s, and today the corporation still holds those rights, which provide water for fountains, fire protection, irrigation and domestic purposes.
While the state's rights system allows Wyntoon to draw the water it needs, the nearby town of Montague, which has no such water rights, is perilously close to running out of water for its 1,500 residents.
Still, the state doesn't know how much water Wyntoon uses. Records putting the estate's reported water usage at 1.8-million acre-feet in 2010 -- enough to sustain more than seven million people -- are wildly inaccurate, said Hearst Corp. spokesman Paul Luthringer.
Actual use, he said, is 448 acre-feet.
It appears to be one of a number of cases where water use was mistakenly reported or recorded as acre-feet instead of gallons, and It's not clear how many of the nearly 4,000 rights holders use more or less water than state records show.
Hearst didn't know about its records problem until contacted by AP. "We are concerned and will contact the agency about the discrepancy,'' said Luthringer.
The Hayashi family was part of a pioneering group of Japanese-American farmers who settled along the central California coast to till the land about a century ago.
They planted bush peas near what is now San Luis Obispo, but California's Alien Land Act, enacted in 1913 and later struck down, prevented the Hayashis and other non-U.S. citizens from owning land.
The family eventually got their own parcel when a friend who was a U.S. citizen bought it and sold it to them, said Alan Hayashi, a third-generation farmer who manages Y. Hayashi & Sons' office.
In the 1930s the family started using water from the Arroyo Grande creek next to their farm. This simple act established the family's superior right to the water and has helped to sustain their business, he said.
But after Japan's attack on Pearl Harbor drew the nation into World War II, Hayashi's forebears were sent to an internment camp for people of Japanese heritage. Farming came to an abrupt halt, and crops were left in the fields.
Friends and neighbors watched over the family's land to keep it from being taken, Hayashi said. But, when the elder Hayashis returned several years later, they continued to face discrimination.
"While some people were still calling names, there were others who said 'if you need to use my tractor, use my tractor,''' Hayashi said.
Today the family uses its water rights to irrigate about 94 acres of leafy green vegetables, strawberries, corn and tomatoes.
Hayashi was surprised to learn that state records showed the farm had used 875,000 acre-feet of water in 2010 to irrigate its farm.
"That's a huge crazy number,'' Hayashi said. In reality, he said, they only used about 550 acre-feet.
As the air warms and soil is plowed for planting, water master Donnie Stinnett prepares for rice farmers' springtime ritual: flooding the fields with water.
The farmers who belong to the Joint Water Districts Board Stinnett manages about 60 miles north of Sacramento face no drought-related restrictions this year because they have century-old water rights.
In the 1880s, farmers, land developers and investors established them by building canals from the Feather River to nearby fields, said the district's attorney, Paul Minasian.
By 1904, he said, a group of landowners signed an agreement to buy and distribute some of the water from what became known as the Sutter Butte Canal, cementing the right to the water.
The Joint Water Districts Board now operates that same canal for four water districts that inherited the water rights.
When state water officials dammed the river and built Lake Oroville, the districts retained the right to use 555,000 acre-feet in the typical growing season, except in conditions that are more extreme than the current drought.
They use the water to irrigate rice, alfalfa, row crops, and fruit and nut orchards. And the flooded rice fields double as habitat for migratory birds.
A quiet retirement community in Carmel seems a most unlikely candidate to be listed among state's top water users -- but California water data showed the Hacienda Carmel Retirement Community had reported using roughly 8.36 million acre-feet from the Carmel River in 2010 -- more than Los Angeles or San Francisco.
"Obviously 8 million acre feet is a small inland sea, so it's just not reasonable,'' said accountant Jeanne Mileti. "It was just a clerical error, so I'm talking to them and getting it rectified.''
The 300-home condo community was built in 1962 on about 50 acres next to the Carmel River, said general manager Robert Hedberg.
The facility uses its water rights to irrigate the grounds, including the trees and lawns. But, out of sensitivity to the state's water shortage, the community recently started converting to drought-resistant landscaping and installing rainwater collection barrels to conserve water.
"We have made a good start at changing over because we recognize the need for change in that regard,'' Hedberg said.