In California's second-largest city, memories are still fresh of a devastating drought 25 years ago that saw the area's water supplies slashed by about a third.
Billions of dollars were invested to prepare for the next drought, an effort that included building the Western hemisphere's largest desalination plant, which opens this fall.
Yet the moves count for nothing under sweeping statewide cuts to urban water use approved this week that require hundreds of cities, counties and local agencies to reduce consumption between 8 percent and 36 percent from 2013 levels, starting June 1. The largest per-capita users must make the biggest percentage cuts, no matter how and where they get their water.
San Diego isn't the only place complaining. The Orange County Water District, which serves 2.4 million people near Los Angeles, wanted credit for sending wastewater through ground basins for drinking. It started recycling water in 2008 and is boosting production to 100 million gallons a day from 70 million.
San Diego, which imports nearly all of its water, launched its quest for water independence in 1991, after the Metropolitan Water District of Southern California said it was cutting deliveries in half. Metropolitan, a giant wholesaler based in Los Angeles, supplied 95 percent of San Diego's water at the time.
Surprise rains reduced the cut to 31 percent, which lasted 13 months. Still, businesses led by the city's biotech industry demanded change.
"That really was a wakeup call," said Dana Friehauf, water resources manager for the San Diego County Water Authority, which supplies 3.1 million people in the city of San Diego and its suburbs. "We heard loud and clear from residents and businesses in San Diego County that we needed to take action to avoid that from happening again."
Metropolitan now supplies less than half of San Diego's water and will deliver less than a third in 2020. But the diversification has been costly.
In 2003, San Diego began buying water from California's Imperial Valley in the nation's largest farm-to-city water transfer, a move that San Diego leaders said would offer protection during drought because Imperial Valley's senior rights to Colorado River water put them at the front of the line.
In 2012, San Diego sought more protection by agreeing to buy water from a $1 billion desalination plant in suburban Carlsbad. The hemisphere's largest such plant will produce 50 million gallons a day by 2020, enough to satisfy 7 percent of regional demand. It will raise the region's average residential water bill by $5 to $7 a month.
San Diego's march to independence earned little sympathy from the State Water Resources Control Board, which approved the cuts to achieve Gov. Jerry Brown's target of reducing urban water use 25 percent. Board officials say those who prepared for drought will be better off in the long run.
"This is not about being fair, giving kudos for past performance," said board Chairwoman Felicia Marcus. "This is about dealing with what is an emergency out in front of us that may not be right here, but we can see coming at us."
In November, the city of San Diego moved ahead on a $2.5 billion plan to recycle 83 million gallons of wastewater a day for drinking by 2035, about one-third of the city's supply. It warns, however, that public support may wane if cities don't get credit for such investments.
"The frustrating thing is it feels we have done the right things, invested in the right things and tried to be very responsible," said Mark Cafferty, chief executive of the San Diego Regional Economic Development Corp., a business coalition.
"I absolutely agree with the narrative" to diversify supplies, said Mayor Steve Vaus of Poway, a San Diego suburb that must cut use 32 percent. "The problem is that, to date, it has fallen on deaf ears."
Steve Erie, a political science professor at University of California, San Diego, said the cuts "absolutely blindsided" the region, which erred by locking in long-term contracts for desalinated water and with the Imperial Valley deal.
"They were overeager investors," he said. "It's a failure of planning."
Many San Diego government officials and business leaders insist it is a temporary setback. They say any unused water can be stored in a newly retrofitted dam and tapped if drought persists.
Gary Arant, general manager of Valley Center Municipal Water District, said state regulators had to act quickly. His agency, which serves homes with fruit trees on large lots north of San Diego, must cut use 36 percent.
"In the short term, the investment hasn't worked out as we hoped," he said. "We think, in the long term, the San Diego region will be better off."
— Associated Press writer Fenit Nirappil in Sacramento contributed to this report.