The reason for the advisory is unknown; an explanation for the levels of San Diego County’s Beach & Bay Program is provided.

The San Diego County Department of Environmental Health and Quality has issued a water advisory April 2 for La Jolla Shores 150 feet north and south of Vallecitos.

A March 19 advisory for La Jolla Shores at Avenida de la Playa is ongoing.

Bacteria levels exceed health standards, according to the advisories, and water contact should be avoided to prevent illness.

Meanwhile, a La Jolla Cove advisory in place since January was lifted a few days ago.

Often, water advisories lead to speculation and further questions about the causes, but county spokesperson Donna Durckel emphasized the reason for an advisory is often unknown.

Bacteria levels could be higher due to a natural occurrence, animal activity, storm runoff, environmental conditions and more, she said.

The county usually cannot determine the cause; county officials are charged with monitoring bacteria levels and clearing the advisory when bacteria counts fall within state limits.

One reason can be ruled out, however: sewage spills result in an immediate closure, Durckel said, according to state law.

A water advisory – marked by a white sign with a yellow border – is the first level of the county’s Beach & Bay Program actions. 

A water warning – a blue sign with an orange border – is issued only in South County, when there are swell conditions that may be pushing bacteria north from the Mexican border.

A beach closure – a yellow sign with a red border – is enacted when a sewage or chemical spill impacts ocean or bay waters.

For updates on beach advisory and closure information, visit sdbeachinfo.com.