by: Katie Chavez
Posted: Jul 21, 2026
(FOX40.COM) — Despite multi-million-dollar efforts to combat an invasive species’ impact on a key California water source, Yolo County was forced to declare a local emergency in its latest attempt to slow the spread.
The Yolo County Board of Supervisors proclaimed a local emergency Tuesday as golden mussels continue to threaten the Sacramento-San Joaquin Delta, officials explained in a news release.
This proclamation comes after Sacramento County, San Joaquin County and the City of Stockton also declared local emergencies. The county said a local emergency status will allow for smoother coordination across agencies and organizations.
“Golden mussels do not stop at city, county or agency boundaries,” said Oscar Villegas, Yolo County Supervisor for District 1. “We need a coordinated regional response that helps protect water reliability, flood-control systems, agriculture and local infrastructure.”
This coordinated effort comes after golden mussels were detected near waterways in the Port of West Sacramento in June.
The state took a harsh stance towards the uninvited mollusks right away, investing $6 million to combat their spread in late June after state officials became worried that their presence would increase maintenance costs and harm the state’s water supply.
The Sacramento-San Joaquin Delta, a collection of waterways threatened by the mussels, supplies “fresh water to two-thirds of the state’s population and millions of acres of farmland,” according to the California Department of Water Resources.
Yolo County’s proclamation is the latest step in a months-long process to find an answer to the tiny-but-mighty threat. Besides their stubborn attachment to “rocks, docks, water intake structures, pipes, pumps and other key waterway infrastructure,” mussel colonies can become dense enough to clog pipes, engines and other “water-conveyance” systems, Yolo County officials explained.
If that weren’t enough, the mussels rapidly reproduce, and their tiny larvae can spread through vehicles and water without human detection, which amplifies the aforementioned attachment and clogging issues.
Although experts decided that total elimination of the mussels is impossible, county officials have urged residents to participate in efforts to slow the golden mussel infestation from progressing further.
The county gave the following recommendations to help prevent the mussels’ spread:
- Clean off all visible aquatic plants, animals, and mud from boats, trailers, anchors, fishing gear, and other equipment.
- Drain all water from bilges, live wells, motors, ballast tanks, bait buckets, and any other water-containing devices.
- Dry all equipment completely for at least five days before launching into another waterbody.
To learn more about how to prevent the spread of invasive aquatic species, visit the website stopaquatichitchhikers.org.