Remember that wild October storm — the one that made your window look like Dorothy’s house mid-twister? Winds whipped, rain pounded, and for a brief moment Southern California felt more like the Midwest in tornado season. But while most of us were inside watching branches fly, San Juan Creek was surging seaward, pouring into Doheny’s surf line like a muddy ribbon unraveling across the blue.
From above, the contrast was startling. Drone footage captured by local photographer Greg Viviani showed chocolate-colored runoff colliding with turquoise ocean water, the difference so sharp you could almost see the two viscosities struggling to blend. In an interview, Viviani explained that the footage serves as a clear reminder of why the 72-hour rule for surfing after a rain exists — especially the first one of the season. He emphasized the importance of being mindful about what gets washed into storm drains, since everything upstream eventually flows into the Pacific Ocean.
The culprit behind the flood wasn’t entirely natural. Witnesses reported that people with shovels helped breach the sand berm that typically holds back San Juan Creek, releasing the backed-up water all at once. Among those who came to observe was professional skimboarder Blair Conklin, who described the water conditions as “foul” and noted the visible pollution coating the waves.
Conklin remarked that the air around the creek smelled unpleasant and predicted a significant amount of plastic and debris would wash ashore, suggesting that a large beach cleanup would likely be needed following the storm.
Southern Californians are no strangers to post-storm warnings, but this event was a vivid reminder of how quickly inland runoff can pollute our coastal breaks. The first heavy rain of the season flushes everything that has accumulated on streets, lawns, and parking lots — oil, fertilizers, trash, bacteria, and even pet waste — straight into the sea. In just hours, a few inches of rain can undo months of ocean-protection efforts.
The Ripple Effect
Runoff isn’t just unsightly; it’s dangerous. Stormwater systems were built to prevent flooding, not to filter pollutants. Unlike sewage, which goes to treatment plants, runoff gushes untreated into rivers, creeks, and finally the ocean. The result: high bacteria counts that close beaches, toxic nutrients that spark algae blooms, and debris that chokes marine life.
After wildfires, the risks multiply. Ash and charred debris from burn scars mix into the flow, carrying heavy metals and synthetic chemicals downstream. That combination can create a toxic slurry that harms fish, seabirds, and even beachgoers who breathe in the particles or touch contaminated foam.
According to Matt Sylvester, Communications Director for the Orange County Coastkeeper and Inland Empire Waterkeeper, the effects of runoff can linger long after the rain stops. “Stormwater runoff is the leading cause of ocean pollution in Southern California. The first major rains of the season wash months of built-up pollutants from streets, parking lots, and lawns into rivers and coastal waters. This sudden flush carries metals like copper and zinc from car tires and brake pads, which can be toxic to marine life even in very small amounts. The result is damage to fish, invertebrates, and other species that depend on clean water. Over time, this pollution contributes to harmful algal blooms, domoic acid poisoning, and the overall decline of nearshore ecosystems.”
What We Can Do
While storms like this one are inevitable, their impact doesn’t have to be. Small choices inland make a measurable difference downstream:
Keep storm drains clean — Never dump oil, paint, or yard clippings into the gutter. Every drain leads to the ocean.
Reduce runoff at home — Use permeable landscaping, rain barrels, or native plants to absorb rainfall naturally.
Pick up litter and pet waste — Even items left blocks from the coast wash into creeks when the rain comes.
Join cleanup efforts — Local groups often host post-storm beach cleanups at Doheny and other surf zones.
Sylvester explained that individual actions truly add up when it comes to preventing pollution from reaching the ocean. “Our watershed is all connected, which means what happens on your property can impact our creeks and ocean. When it rains, pollutants like fertilizers, pet waste, and motor oil can all wash into storm drains and flow to the ocean without treatment. You can help protect water quality by sweeping yard waste instead of hosing it into the street, using fertilizers and pesticides sparingly, cleaning up after pets, fixing oil leaks, and washing your car at a commercial car wash, where water is recycled instead of wasted.”
He also encouraged residents to be proactive in their communities. “People can also make a difference by getting involved with their local city or county stormwater programs. These agencies are required to meet specified pollution limits, but public attention helps make sure those regulations are followed and enforced. Finally, if you see anything suspicious entering a storm drain, like oily water, unusual smells, or dumping, report it to your city’s code enforcement or to a local group like Orange County Coastkeeper. Take a photo or video, note the time and place, and share what you see. Local observations are often the first step in stopping pollution.”
Sylvester noted that homeowners’ associations and businesses can also make major contributions by designing properties with runoff management in mind. “Both HOAs and commercial properties can take simple steps to manage stormwater in ways that save money and look great. Bioswales, for example, are landscaped areas that use plants, rocks, and soil to naturally filter pollution from rainwater. They require little maintenance and help keep runoff clean before it enters storm drains. Homeowners can capture and reuse rainwater for irrigation, while businesses can treat and reuse stormwater onsite to reduce both runoff and water costs.”
He added that even something as simple as how lawns are maintained can make a big difference. “A common issue for HOAs is overwatering. Strict landscaping rules often lead residents to water excessively to keep lawns perfectly green, which wastes water and washes fertilizers and pesticides into the storm system. Allowing some browning of grass and encouraging drought-tolerant or native landscaping helps save water and protect local waterways at the same time.”
The health implications of this runoff extend beyond the environment and into the surf lineup. Sylvester explained that the 72-hour rule remains a useful guide but isn’t always enough. “After a storm, the main health risk comes from bacteria carried in runoff. Fecal contamination is common and can cause stomach illness and other gastrointestinal problems. Because most government testing focuses on bacteria, we often don’t know what other chemicals or metals might be present after heavy rain. The 72-hour rule remains a good guideline, but in some areas, especially near storm drain outfalls or enclosed harbors, it’s best to wait even longer, since pollution can linger depending on tides and water movement. For the most up-to-date beach conditions, Coastkeeper recommends visiting theswimguide.org or, for Orange County beaches, ocbeachinfo.com before getting in the water.”
Viviani, who has long advocated for better watershed management around Aliso and San Juan Creeks, noted that proactive measures could help prevent much of the contamination seen after this storm. He emphasized that investment in upstream filtration, retention basins, and community education could significantly reduce the flow of pollutants before they reach the waves.
Storms like October’s serve as an important reminder of how connected everything is — from the storm drain outside your driveway to the lineup at Doheny. With greater awareness and responsibility, we can keep our oceans clearer, our surf safer, and our harbors shining long after the clouds pass.
