Rainstorm runoff is known to transport disease-causing organisms from urban areas to the ocean.

Avoid Ocean Water During and After Rainstorms

Author: Public Health Department
Date: 12/23/2019 10:34:04 AM

The Public Health Department is advising the public to avoid ocean water contact during, and at least three days following, significant rainstorms—such as the recent and predicted storms.


Rainstorm runoff is known to transport high levels of disease-causing organisms such as bacteria, viruses and protozoa from the watershed and urban areas to the ocean. Such organisms carried into the ocean can cause skin, respiratory, and intestinal problems. Young children, older adults, and people with compromised immune systems are especially vulnerable to these waterborne pathogens.

Surfers, swimmers and others are advised to avoid contact with ocean water during this period, especially in areas close to creeks, rivers, storm drains and other runoff outlets that empty into the ocean.

For more information about beach water quality, please visit the Public Health Department Beach Water Quality website at www.slocounty.ca.gov/health/publichealth/ehs/beach, or call the Ocean Water Monitoring Program Telephone Hotline at (805) 788-3411.