Heal the Bay Advisory: Avoid Ocean Swimming for the Next 72 Hours

Los Angeles is seeing the autumn's first rainfall, which means swimming at LA County beaches is not a good idea, according to .

The nonprofit is warning residents not to swim, surf or play in ocean waters near discharging storm drains, creeks and rivers for the next 72 hours, due to the new season's "first flush." The advisory has been issued because high levels of bacteria, debris and trash from city streets and mountain areas have been making their way into the ocean.

“Our region’s water bodies are likely to see significantly higher pollution levels after this rain event,” Heal the Bay water-quality director Kirsten James said in a statement. “With so-many year-round ocean users now, it’s critical that they stay out of the water for a while.”

When the first rainfall of the new season occurs, debris, toxic chemicals and animal waste that have built up in riverbeds, roadways and sidewalks get washed into storm drains, according to the organization. More than 80 percent of debris that is in the ocean stems from sources located inland.

"Exposure to runoff can cause a variety of illness, most frequently respiratory infection and stomach flu," Heal the Bay said in a statement. "Human pathogens of unknown origins are also frequently carried in storm-drain gutters."

The Los Angeles County Department of Public Health issued a similar alert in January.

"Fortunately, discharging storm drains, creeks, and rivers only comprises a small portion of the beach, and therefore, anybody who wants to go to the beach will be able to enjoy their outing," said Dr. Jonathan E. Fielding, director of the county's public health department. "We do advise swimmers and surfers to stay away from the storm drains, creeks and rivers as there is the possibility that bacteria or chemicals from debris and trash may contaminate the water near and around these areas, and some individuals may become ill."

Around the same time, Heal the Bay President Mark Gold told Santa Monica Patch that cities throughout the county were "getting Fs on their beaches this week, because every beach is getting high bacterial counts."

For Heal the Bay's latest water-quality grades, go to HealtheBay.org. For more information on beach conditions, Los Angeles County's beach closure hotline is accessible 24 hours a day at (800) 525-5662. Information also is available here.