LOS BANOS, CA (AUGUST 8th, 2025) – Nearly one year after it was first detected in California, an invasive species known as the golden mussel (Limnoperna fortunei) remains a serious threat to local water systems—and it’s already been confirmed just outside Los Banos. Native to Asia and never before seen in North America, the golden mussel was first discovered in October 2024 at the Port of Stockton. Within weeks, it was confirmed in O’Neill Forebay, part of the San Luis Reservoir system, located just 12 miles west of Los Banos. That reservoir feeds into the California Aqueduct, which supplies drinking water and irrigation to much of the Central Valley, including our city.
These mussels reproduce rapidly and cling to underwater surfaces in thick clusters, clogging pipes, pumps, and gates. Their presence in O’Neill Forebay has prompted major concern, especially for Los Banos residents and farmers who depend on reliable water deliveries. Experts warn that golden mussels can reduce water flow, raise infrastructure maintenance costs, and potentially increase water rates. The infestation also threatens recreational access to the reservoir, with tighter boat inspections and decontamination protocols now in place to slow the spread.
Since the initial discovery, the California Department of Fish and Wildlife (CDFW) and the Department of Water Resources (DWR) have enacted emergency containment measures. These include a $1 million grant program for boat facilities, mandatory inspections at key waterways, and ongoing public outreach campaigns urging residents to follow “Clean, Drain, Dry” procedures when exiting any body of water.
As of August 2025, the golden mussel remains active in O’Neill Forebay and surrounding waterways. State officials have acknowledged that full eradication is unlikely; the priority now is limiting further spread to protect water infrastructure and agriculture across California. For Los Banos, this invasive species is no longer just a regional issue—it’s a local and ongoing environmental threat. Early detection helped, but long-term protection will depend on coordinated efforts from both agencies and the community.
