How San Diego Gets Drinking Water From the Ocean

Take a tour of the Carlsbad Desalination Plant.,


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ImageSunset Cliffs in San Diego, just down the coast from the Carlsbad Desalination Plant.
Sunset Cliffs in San Diego, just down the coast from the Carlsbad Desalination Plant.Credit…Ariana Drehsler for The New York Times

Whenever California is pummeled by drought — as is still very much the case despite recent rain — a lot of people find themselves asking, “What if we got water from the ocean?”

In San Diego County, it’s already happening at a $1 billion facility by the beach.

Recently, as I reported on San Diego’s decades-long quest for water stability, I visited the Carlsbad Desalination Plant, the largest such facility in the country, to see how it works.

The plant, which opened in 2015 after a long, fraught development, essentially creates 50 million gallons of fresh drinking water every day. Seawater flows through a massive intake pipe directly from the Pacific Ocean, where it first gets pumped into tanks that work sort of like Brita filters to take out bigger stuff — like algae — that shouldn’t be in drinking water.

Then the water makes its way through a labyrinth of pipes where more impurities are removed until basically just salt is left. This makes sure the water is ready for the signature, high-tech reverse osmosis desalination process, which takes place in thousands of tubes stacked high in a cavernous building. The loud hum of the machinery echoes through the space.


Jeremy Crutchfield of the San Diego County Water Authority, left, and Sachin Chawla, president of Poseidon Resources, near the reverse osmosis membranes at the desalination plant.Credit…Ariana Drehsler for The New York Times

In each of those tubes, there are rolled up membranes that act like “microscopic strainers,” as officials describe them. The water is pushed through at a high pressure, and the membranes catch the salt and other dissolved minerals until all that’s left is pure H2O.

Finally, the water gets treated to make it more like normal drinking water, before it’s piped miles to be mixed in with the rest of the county’s water, and delivered to taps across San Diego. The salty brine that’s left over gets mixed in with seawater and pumped back into the ocean.

Right now, a relatively small proportion of the county’s water comes from the ocean — about 8 percent. Critics say that it’s some of the most expensive water that exists, and that operating the plant can harm the neighboring ocean ecosystem.

Officials with the San Diego County Water Authority and the private company that runs the plant, Poseidon Water, say that adding desalination has cost each household an average of $5 per month, and that they’re constantly working to make the plant more environmentally friendly and energy efficient.

Above all, they say, the ocean is a rare drought-proof water source worth the investment for some level of certainty.

Other communities up the coast have taken notice amid the drought; some are exploring seawater desalination plants of their own, while others are considering removing salt from brackish water in rivers. Another Poseidon Water plant is in the works for Huntington Beach.

For more:

  • Read the full article about why San Diego has plenty of water, despite a punishing drought.

  • Desalinated seawater has been transformative for Saudi Arabia, as well as other countries in the Middle East and North Africa. But it may be too expensive for many places that need it.

  • The recent rainstorms brought a suspension of the drought curtailment orders that were imposed during the summer. Storm season, which usually runs from November to March, began early this year but officials warn there could soon be another dry spell, The Modesto Bee reports.


An election worker in Eureka uses a mail-ballot sorting machine during the recall election.Credit…Alexandra Hootnick for The New York Times
  • Recall changes: Lawmakers say they will propose constitutional changes to the state’s recall election process, The Associated Press reports.

  • State of California v. Donald Trump: Throughout Donald J. Trump’s presidential term, California filed more than 100 lawsuits against the administration. Even though he is out of office, the state is keeping some lawsuits open in case Trump-era regulations resurface or have lasting effects on Californians, The Sacramento Bee reports.

  • Forced relocation: The Chemehuevi, who currently live on the border of California and Arizona, experience an average of 29 more days of extreme heat there than on their historical lands.

  • Illegal gambling lawsuit: Pong Game Studios, a company that made and operated casino-style games used for illegal gambling, will pay $3.5 million and permanently stop its operations in California, The Associated Press reports.


  • A carbon-free city: Los Angeles is aiming to run entirely on clean energy by 2035. If successful, it would be the first major U.S. city to do so, The Washington Post reports.

  • Secret Border Patrol units: According to a letter sent to Congress this week from the Southern Border Communities Coalition and Alliance San Diego, the Border Patrol has secret units that protect agents accused of wrongdoing, The San Diego Union-Tribune reports.

  • Wild real estate: The One,” a mega mansion in Los Angeles that is one of the most expensive in the country, filed for bankruptcy to avoid foreclosure. The mansion is worth $325 million but has only $176 million in secure loans, Bloomberg reports.

  • School safety officer verdict: Eddie Gonzalez, a former school safety officer, has been charged with one count of murder for the September shooting of Manuela Rodriguez, an unarmed 18-year-old. He is being held on $2 million bail at Long Beach jail.


  • Fresno teachers’ labor grievances: Union representatives for teachers in the Fresno Unified School District announced their plan to file grievances against the district for long-unresolved issues that have worsened in the pandemic. Grievances include losses in personal and prep time and teachers being forced to fill in for colleagues, The Fresno Bee reports.


  • Desert remains: Human remains found in Yucca Valley this month have been identified as those of Lauren Cho, a 30-year-old woman from New Jersey who went missing in late June. The cause and manner of death are pending toxicology reports, The Associated Press reports.

  • Power outages: Ninety-nine percent of the 851,000 people who lost power during California’s atmospheric river storm had power restored by Wednesday at 7 p.m., The Associated Press reports.

  • Brain research: The University of California, San Francisco, is opening a $535 million brain research facility that will be the largest neurology and neuroscience center in the country, The San Francisco Chronicle reports.


Credit…Mark Weinberg for The New York Times

Studded with colored candies, these monster cookies are an amazing way to end a grown-up supper.

Today’s travel tip comes from Ryan Ver Berkmoes, who recommends Rio Del Mar State Beach in Santa Cruz County:

Facing the ocean, to the left, there is a seemingly endless sweep of sand curving right around the Monterey Bay. Walk just a few minutes and you might see sea otters languidly bobbing on their backs in the surf plus dolphins and seals prowling for fish while whales spout offshore. Watch for fins as great white sharks spawn here. What you won’t see are people as you get swallowed up in the sandy expanse.

Look to the right and you see the cement boat (otherwise called the concrete ship), a once large tanker built out of cement that was moored off the beach in 1929 as an entertainment pier. Now crumbling into nothing, there’s a great little museum where you can learn the entire improbable history.

Add to this a superb little deli with sandwiches for beach picnics and it’s the perfect day out. A few years ago my wife and I and a bunch of those closest to us rented houses on the sand for the week of our wedding. Truly incredible.

Tell us about your favorite places to visit in California. Email your suggestions to We’ll be sharing more in upcoming editions of the newsletter.


Credit…Trisha Krauss

Buy Nothing groups are flourishing across the country.

They’re networks of people, mostly on Facebook, who give and receive things for free — treating the stuff taking up space in their homes as gifts meant to be shared and treasured.

In a time of isolation, Buy Nothing is fostering a quirky sense of community.

Thanks for reading. Enjoy your weekend. We’ll be back Monday.

P.S. Here’s today’s Mini Crossword, and a clue: Pink Nintendo character (5 letters).

Soumya Karlamangla, Steven Moity, Shivani Gonzalez, Mariel Wamsley and Jordan Allen contributed to California Today. You can reach the team at

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