After Rain, Avoid Swimming at Beaches: County

The County urged residents to avoid swimming at beaches due to increased bacteria levels after rainfall

San Diego County is in the middle of its first fall storm of the season. With that rainfall, the county is warning residents to stay away from swimming at San Diego beaches because of a rise in bacteria levels from urban runoff.

A water contact closure was issued for the shoreline from the U.S.-Mexico Border to Imperial beach on Thursday due to sewage-contaminated runoff.

The county's Department of Environmental Health said the rain was pushing the tainted water through the Tijuana River and into the United States. 

Signs would remain up until the closure was listed, the DEH said. 

The area is often closed after heavy rain due to sewage runoff from Mexico. A diverter, part of an agreement between the U.S. and Mexico, is shut down during heavy rainfall, according to the San Diego County Department of Environmental Health.

The issue has long spark contention between the South Bay community and the International Boundary Water Commission, the agency that manages issues that affect both the U.S. and Mexico's waters.

In 2018, local governments in the San Diego area sued the International Boundary Water Commission (IBWC) over the spills but in October, Mexico pledged to rehabilitate five pumping stations in Tijuana to prevent cross-border sewage spills. 

While other shorelines in San Diego County were not closed, officials warned residents from swimming in coastal waters right after the rain. 

The worst urban runoff is typically near storm drains, creeks, rivers and lagoon outlets which contain bacteria from animal waste, soil or decomposing vegetation, according the San Diego County Department of Environmental Health.

Matt O'Malley with San Diego Coastkeepers said it's not just bacteria lurking in urban runoff that people should be worried about, but also pesticides and toxic metals from aging infrastructure.

The advisory is in effect for 72 hours. NBC 7’s Alexis Rivas investigates where the potential contamination comes from.

The County’s Beach and Bay Water Quality Program’s interactive map showed a General Rain Advisory for dozens of local beaches in San Diego County from Oceanside to Imperial Beach. As of Wednesday morning, the Tijuana River’s status was at a low risk. The Tijuana River can impact California beaches when it rains, sending sewage and other contaminants into local beaches, according to the County.

NBC 7 captured this image below of trash collecting on Monument Road, near the Tijuana River.  

Fall rain flood imperial beach urban runoff 1

The San Diego County Department of Environmental Health said that rain advisories are issued when the rainfall is equal to or greater than .20 inches. The County advisory is in effect for 72 hours after the last rain.

Some kiteboarders were seen riding the waves, despite the current advisory.

"Any chance to get out when it's windy and get out kiteboarding, we're going to take," kiteboarder Alan Mondus said.

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