California beach water quality declines amid record rainfall, sewage spills

Water quality at California beaches saw a decline last year, largely due to record-breaking storms and an increase in sewage spills, according to a recently published report by environmental nonprofit Heal The Bay. The group’s 34th annual Beach Report Card assigned grades ranging from A to F to more than 700 beaches along the Pacific Coast, spanning from Washington state down to Baja California, based on bacterial pollution levels observed under various weather conditions.

Nearly 90% of monitored California beaches received A or B water-quality grades for the dry-weather summer months. That figure is close to the state’s 10-year summer average, but does mark a 6% drop from the last Report Card.

“Eighty-nine percent of California beaches were safe to swim at during summer 2023, but we are still seeing water quality impacts from record-breaking storms, urban runoff, and sewage spills,” said Tracy Quinn, CEO and president of Heal the Bay. “California’s 20th century water infrastructure was not designed to address the challenges faced by climate change in the 21st century. We need to upgrade outdated sewage treatment facilities and prioritize public investment in nature-based, multi-benefit stormwater capture infrastructure.”

During the dry winter season (Nov. 2023-March 2024), only 66% of the 501 beaches monitored in California received overall A or B grades, well below the state’s 10-year winter average. In Northern California, 50% of beaches tested received A and B grades under dry winter conditions, reflecting below-average performance. The situation was more severe in Southern California, where 70% of beaches received these grades. The increase in bacterial levels was largely due to the intense rain events that washed more contaminants into the ocean.

Coastal counties in California received 31% more rainfall during the winter reporting period than the 10-year average. The deluge flushed bacteria and other pollutants through storm drains into the ocean and caused numerous sewage spills, which dramatically impacted water quality.

The poor winter grades underscore two of the biggest ongoing beach water-quality challenges for the state: worsening climate change and crumbling infrastructure.

Only 12 of the over 500 monitored beaches in California earned a spot on Heal the Bay’s Honor Roll. Of these, all but three are located in Orange County. Notably, the Point Loma Lighthouse in San Diego maintained its Honor Roll position for three consecutive years.

“Historically, the Honor Roll has been dominated by Southern California beaches, partly because many Northern and Central California counties do not monitor water quality year-round,” according to the report. “However, this year’s severe winter weather affected water quality across all regions.”

Conversely, multiple beaches ended up on Heal the Bay’s Beach Bummers list, which ranks the 10 most polluted beaches. This year, two beaches in Northern California, six in Southern California, and two in Mexico were named. The report calls attention to California’s aging sewage infrastructure, which struggled to cope with the increased rainfall and urban runoff.

“More frequent and more severe storms will only exacerbate the urban runoff that pollutes our sea. It’s critical that the state and municipalities invest in more stormwater capture projects that will cleanse, hold and reuse water rather than sending polluted runoff to the sea. It’s a double-win for our drought-challenged state,” reads the report. “Separately, the state is seeing an uptick in sewage spills thanks to overtaxed sanitation systems during storms and to outdated sewer systems that are breaking down because of age or inadequate upkeep.”

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