The Department of Environmental Health has issued a General Advisory for the coastal waters of San Diego County due to Thursday's and Friday's rainfall.
Swimmers, surfers, and other ocean users are warned that the levels of bacteria can rise significantly in ocean and bay waters, especially near storm drains, creeks, rivers, and lagoon outlets that discharge urban runoff.
Urban runoff may contain large amounts of bacteria from a variety of sources such as animal waste, soil, and decomposing vegetation.
As is custom when the Tijuana River flows after rainfall, beaches have been closed from the north end of the Tijuana Estuary to the U.S.-Mexico border due to sewage contaminated runoff.
While many coastal storm drains within San Diego County are permanently posted with white metal warning signs, additional temporary warning signs are not posted for general advisories such as this.
Activities such as swimming, surfing and diving should be avoided in all coastal waters for 72 hours following rain. This includes all coastal beaches and all of Mission Bay and San Diego Bay.
Elevated bacteria levels can persist after a rainstorm depending upon the intensity of the storm, volume of runoff and ocean and current conditions.
– From a county Department of Health news release.