If you've tried to swim at Coronado Beach in 2026 and found closure signs in the sand, here's why. A wastewater pipeline in Tijuana collapsed twice in May, sending millions of gallons of raw sewage into the Tijuana River and out to the Pacific Ocean. Ocean currents carried that contamination north through Imperial Beach, up through Silver Strand State Beach, and into Coronado's shoreline. The San Diego County Department of Environmental Health and Quality responded with water contact closures that shut down sections of Coronado Beach in March, April, June, and July.
This isn't new. It's worse than it's been, but it isn't new.
What Happened
The South Bay International Wastewater Treatment Plant in San Ysidro was designed to handle 35 million gallons per day. During the May pipeline collapse, it was treating up to 60 million gallons per day of untreated flows. That's nearly double capacity. The plant couldn't keep up, and what it couldn't treat went into the river and then into the ocean. The U.S. International Boundary and Water Commission said the pipeline that ruptured was a 10-mile line already undergoing rehabilitation. It collapsed once around May 14 and again on May 29. The second collapse was the big one.
Bacteria readings told the story. The county's testing station at Avenida Lunar in Coronado recorded 201,814 copies of fecal indicator bacteria DNA. The Silver Strand Guard Shack station hit 288,232 copies. The state health standard is 1,413. Those aren't marginal exceedances. Those readings are 140 to 200 times above safe levels.
What a Closure Actually Means
The county uses two levels: a closure and an advisory. A closure means the beach is off-limits to all water contact because of an imminent health threat. Sewage or chemical contamination has been confirmed in the water. You shouldn't swim, surf, wade, or let your dog in. A closure stays in place until testing confirms the contamination is gone.
An advisory is a step down. Bacteria levels exceed state standards, but the immediate health threat is lower. The county advises avoiding water contact, but the beach itself isn't closed. You can still walk on the sand. You just shouldn't go in the water.
On July 1, the Avenida Lunar station was downgraded from closure to advisory. On July 3, the Coronado Main Lifeguard Tower followed. Silver Strand State Beach stayed under a full closure that had been in place since June 2. That downgrade came just in time for the Fourth of July weekend, and it mattered for the island's businesses and tourism. But advisory status still means the water contains bacteria above safe levels.
The Scope of the Problem
The San Diego County Department of Environmental Health and Quality reports an annual average of 73 beach closure days per year for Coronado between 2020 and 2025. Silver Strand averaged 152 closure days. Imperial Beach averaged 231 days. That's most of the year, every year, for Imperial Beach.
Tijuana's population has grown to about 2.3 million people, and the sewage infrastructure was built for a fraction of that. Seventy-five percent of Tijuana's wastewater network and half of its pump stations need repairs, according to a 2026 report coordinated by the Prebys Foundation and San Diego State University. Billions of gallons of untreated wastewater cross the U.S./Mexico border annually through the Tijuana River, carrying sewage, industrial chemicals, and trash into the estuary and the Pacific.
Chris Howard, president and CEO of Sharp HealthCare, which operates Sharp Coronado Hospital, said at a March press conference that the crisis isn't just environmental. "For years, untreated sewage flowing across the border has contaminated our water, our air, and our coastline," Howard said. "Communities in the South Bay have lived with beach closures, foul odors, and exposure to harmful bacteria and toxins."
And it's not just the water. Hydrogen sulfide gas, the chemical that smells like rotten eggs, becomes airborne when untreated wastewater sits in the Tijuana River channel. The San Diego County Air Pollution Control District issued air quality advisories for South Bay communities in 2026, citing elevated hydrogen sulfide levels. The gas causes headaches, nausea, and respiratory problems.
What's Being Done
Federal, state, and local agencies are all involved. EPA Administrator Lee Zeldin visited Coronado in February 2026 to meet with local officials, business owners, and military leadership. He said projects in Mexico are slated to be completed in 2026, including a critical sanitation pipeline. "Progress has already started, and we will stay on top of Mexico to make sure that they all get done," Zeldin said at a press conference on the island.
Congress has appropriated over $300 million so far toward addressing the crisis. The IBWC's Principal Engineer Ramon Macias told the San Diego Water Board in June that rehabilitation of the Parallel Gravity Line, the pipeline that ruptured twice in May, is estimated to be finished by August 2026. The California Coastal Commission unanimously approved a county permit in June to extend two culvert pipes beneath Saturn Boulevard to redirect Tijuana River flows and reduce airborne hydrogen sulfide.
The county also launched a Tijuana River Sewage Crisis Economic Impact Study in June 2026. Residents, business owners, and workers affected by the crisis can participate through online surveys, and findings will be published this fall. And the county is partnering with UC San Diego on a yearlong study to identify chemicals in the air from untreated wastewater flows.
Coronado Mayor John Duncan attended the February press conference. "This issue has a massive effect on the health of the region, the environment, also on our businesses, our military," Duncan said. "It's a true environmental disaster."
What It Means for Coronado
Coronado Beach is one of the most recognized beaches in California. It's been named a top beach in the country by multiple publications. Hotel del Coronado sits right on the sand. The Coronado Golf Course runs along the coastline. Tourism and beach access are central to the island's economy.
When the beaches close, the damage ripples through everything. Fewer visitors eat at restaurants along Orange Avenue. Surf lessons get canceled. Beach rental companies lose revenue. Hotels see lower occupancy. The Coronado Chamber of Commerce and local business owners have been vocal about the economic toll, and the county's new economic impact study is a direct response to that pressure.
Can you swim at Coronado Beach right now? As of early July 2026, city beaches are under an advisory, not a closure. That means you can go on the sand, but the county advises against water contact. Silver Strand remains fully closed. And conditions change frequently. Before you go, check sdbeachinfo.com or call 619-338-2073.
Is Coronado Beach worth visiting? Absolutely. The beach is still beautiful. The sand is wide and golden. The views of Hotel del Coronado and Glorietta Bay are still there. You can walk, sunbathe, build sandcastles, and watch the sunset without going in the water. The sewage crisis is real and serious, but it hasn't changed what makes this stretch of coastline special. It's just changed what you can safely do in the water on any given week.
The fix won't be fast. Estimates put the full cost of adequately treating sewage on both sides of the border at around $1 billion. Only a fraction of that has been funded. But the projects in the pipeline, both literally and figuratively, are real. The question is whether they'll outpace the deterioration of the infrastructure in Tijuana. So far, it's been a losing race. But Coronado isn't giving up on its coastline. Neither should you.
