Beach Water Quality

How Are We Doing?

Beach water quality received a neutral rating because while the total number of water quality events in San Diego County has decreased, events originating exclusively from local pollution (excluding closures and advisories associated with outflows from the Tijuana River) increased and overall the number of water quality events remain very high. 

The number of water quality events originating exclusively from local pollution (excluding closures and advisories associated with outflows from the Tijuana River) increased from 26 Beach Mile Days in 2017 to 46 in 2018. When impacts from the Tijuana River are included, the total number of beach closures and water quality advisories in San Diego County decreased from 697 Beach Mile Days in 2017 to 394 in 2018.

Carlsbad and Solana Beach had the best water quality among San Diego County beaches; in contrast, Imperial Beach and the Border Field State Park/Tijuana Slough National Shoreline had a significant number of water quality issues, largely associated with sewerage outflows from the Tijuana River. Want to know more about what we're measuring?

minus7

Neutral from 2017 to 2018


What Are Beach Mile Days?

Beach Mile Days (BMD) are calculated by multiplying the distance of beach posted or closed by the number of days of the posting or closure. This ensures that a closure to a small section of beach is weighted differently in the overall total to a closure of a large section of beach.

Data Source: San Diego County Department of Environmental Health, 2018

In San Diego County, beach closures increased from 0.3 Beach Mile Days in 2017 to 7 Beach Mile Days in 2018 (see below for closures associated with Tijuana river).

Separately, beach water quality advisories, issued when bacteria levels exceed health standards, were up from 26 Beach Mile Days in 2017 to 39 Beach Mile Days in 2018.

Data Source: San Diego County Department of Environmental Health, 2018

Closures due to the Tijuana River reduced from 671 Beach Mile Days in 2017 to 348 Beach Mile Days in 2018. Despite this reduction, closures remain high and impacts from the Tijuana River continue to have a significant impact on San Diego's southern beaches.

Data Source: San Diego County Department of Environmental Health, 2018

The San Diego County Department of Environmental Health issues rain advisories in response to significant rainfall events that can bring urban runoff into the ocean and cause bacteria levels to rise. The County warns beachgoers to avoid water contact during rain and for 72 hours following the rain event.

Why is it Important?

High quality of life means a clean environment, a thriving economy, and an equitable place for all to enjoy.

  • For decades Imperial Beach, a predominantly lower income community with 51% of the population identifying as Latinx in southern San Diego County, has been subject to beach water quality issues due to sewage-polluted water flowing in from the Tijuana River. The polluted water leaves swimmers and surfers vulnerable to contracting a host of bacterial and viral infections.
  • Beach closures have a negative impact on the tourism economy because everyone loves the beach in San Diego. Heal the Bay estimates the public health cost of gastrointestinal diseases caused by contact with southern California's polluted beach water to be between $21 - $51 million annually.

San Diego County Beach Advisories and Closures in Beach Mile Days

Selected Beaches 2018This map of the San Diego Coast shows the number of Advisories and Closures in Beach Mile days of 2018

Data Source: San Diego County Department of Environmental Health, 2018

Carlsbad and Solana Beach had the best water quality among San Diego County beaches in 2018. While overall water quality improved from 2017 levels, the Border Field State Park/Tijuana Slough National Shoreline had a concerning 236 Beach Mile Days of advisories and closures, largely due to impacts from the Tijuana River.

Regional Response

Partnerships

While there has been some progress on the border sewage issue, much still needs to be done to create a unified plan of action that halts pollution in the Tijuana River Estuary and coastline. Surfrider San Diego and WILDCOAST have developed relationships with key agencies and the community on both sides of the border to focus on positive and tangible solutions.

In addition, the cities of Imperial Beach and Chula Vista, the Port of San Diego, Surfrider Foundation, the San Diego Regional Water Quality Control Board, the California Attorney General Xavier Becerra, the State Lands Commission, and the City of San Diego have all filed lawsuits against the International Boundary and Water Commission to push the federal government to remediate the problem.

Projects

In addition to municipal water departments and local water authorities, several nonprofits in San Diego County are measuring water quality and working on water policy issues. The Surfrider Foundation’s Blue Water Task Force performs supplementary coastal water quality testing in Imperial Beach, Coronado, and Baja. The data collected is available online and provides information to public agencies, environmental researchers, beach communities and beach-goers.


U.S.-Mexico Border Region

Ocean water does not conform to national boundaries. It's therefore important to also look at water quality in the broader transnational region, that includes Tijuana and the northern Baja California beaches in Mexico. Data from the Tijuana Waterkeeper and its parent organization, Proyecto Fronterizo de Educación Ambiental (PFEA), indicates that, overall, beaches south of the U.S./Mexico border had reduced bacteria exceedance advisories in 2018. Despite this overall reduction, San Antonio del Mar continued to struggle with water quality throughout the year, with 47% of tests exceeding the acceptable bacteria standard set by the Mexican Government.


What Are We Measuring?

We measure the yearly trend in beach closures by tracking the total number of days San Diego beaches were closed or flagged with advisories due to health risks, measured in Beach Mile Days (BMD = number of days x length in miles of beach under advisory or closed). We also map out select beach advisories and closures along the San Diego coast and into Tijuana. Learn more about the data.