One Of 2024's Best Beaches In America Was A California Gem Now Sadly Too Polluted For Swimming In 2025

Come to San Diego, home to California's oldest city, for the vibrant streets and tasty food, but if you're planning a beach trip, you may want to think twice, or at least be cautious about where you go, before vacationing in America's Finest City. In 2024, San Diego's Coronado Beach was the only California beach to make the list of Dr. Beach's best U.S. beaches, ranked by coastal scientist Stephen Leatherman (via CNN). The beach also earned a Traveler's Choice Award from Tripadvisor as one of the country's top 25 beaches. However, on Memorial Day weekend of 2025, visitors of the beach were met with warning signs of contaminated waters and closed-off swimming areas. The culprit is what's become known as the Tijuana River Sewage Crisis.

The Tijuana River has been a problem for the U.S.-Mexico border since the South Bay International Wastewater Treatment Plant was built in the early 1990s. It was meant to prevent untreated sewage from entering the ocean, but as Tijuana's population ballooned, the plant simply couldn't keep up. Its infrastructure is outdated, funding for upgrades is lacking, and coordination between the U.S. and Mexico on what to do about the failure has been weak. Over 31 billion gallons of raw sewage have ended up in the Tijuana River Valley and Pacific Ocean since October 2023, the San Diego Coastkeeper reported.

Enough of that sewage has leaked into the waters around Coronado to become a serious health concern. The U.S. Centers for Disease Control and Prevention published an investigation on the impact of the crisis in San Diego and reported that almost two-thirds of study participants from San Diego County experienced medical symptoms related to sewage exposure. It also found that those who came into contact with contaminated water were more likely to have symptoms — hence, the importance of abiding the city's beach warnings.

With the closure of Coronado's shoreline — which includes some of San Diego's most underrated tide pools — comes fewer visitors, who were interested in swimming at the beach. With fewer visitors, less lodgings are being booked, and the city starts to face a snag in its tourism economy. "My biggest concern as mayor is that the reputation as 'the toilet of Mexico' starts to stick at some point and really hurts us," Coronado's mayor John Duncan said in The New York Times in May 2025.

The closures aren't permanent, though, so long as sewage can be cleared out and improvements are made to the treatment plant. On May 20, 2025, the International Boundary and Water Commission released an announcement that it's fast-tracking an expansion of the treatment plant to process 10 million more gallons of sewage per day, expected to be completed 100 days from the announcement. The expansion would help reduce how much sewage ends up in the ocean and around San Diego.

For now, visitors and local beachgoers can check sdbeachinfo.com, San Diego County's beach water quality index, to see when the beach has an advisory or is closed. There's still plenty to do for the whole family in San Diego beyond the beaches, like exploring one of the best Little Italys in America.