Hydrilla in California: Eradication and Quarantine
Learn about California's strict zero-tolerance policy for hydrilla, rapid response eradication programs, and the threat to the state's water infrastructure.
The Western Threat
While Southeastern states have largely accepted Hydrilla verticillata as a permanent, albeit incredibly expensive, resident, California views the plant as an existential threat to its economy and water infrastructure.
The state operates under a strict mandate: total eradication. The California Department of Food and Agriculture (CDFA) leads rapid-response teams to quarantine and destroy any population of hydrilla as soon as it is detected.
The Infrastructure Risk
California's agriculture industry (which supplies a massive portion of the nation's produce) relies on thousands of miles of concrete-lined irrigation canals and aqueducts.
- Flow Restriction: If hydrilla were to establish in the Central Valley Project or the State Water Project, the friction from the biomass would drastically reduce the volume of water the canals could move.
- Pump Clogs: The massive pumps required to move water over mountain ranges would be continually fouled by floating fragments.
- The Clear Lake Battle: One of the most famous eradication efforts occurred in Clear Lake, where the state spent over a decade and millions of dollars using heavy fluridone treatments to eradicate a stubborn infestation.
Prevention and Quarantine
Because eradication is so difficult due to the plant's tubers, California relies heavily on prevention. Border agricultural inspection stations routinely inspect boats being trailered into the state from infested areas like Texas or the Southeast.
If an infestation is found, the CDFA will close the lake to all boating and recreation to prevent fragmentation, and they will implement a multi-year protocol using herbicides and benthic barriers. For more details on why California prohibits mechanical harvesting, see our California removal regulations guide.
Explore Related Topics
Professional Hydrilla Removal Services
Dealing with a severe hydrilla infestation? DK Aquatic provides commercial-grade mechanical harvesting, pond removal, and comprehensive lake management services across the United States, specializing in California and high-priority zones.
Contact DK Aquatic for a ConsultationReferences
Information presented on this page is supported by peer-reviewed research, federal agencies, and state resource management programs.
- U.S. Geological Survey (USGS) – Nonindigenous Aquatic Species Databasehttps://nas.er.usgs.gov
- U.S. Army Corps of Engineers – Aquatic Plant Control Research Programhttps://www.erdc.usace.army.mil
- NOAA Aquatic Invasive Species Programhttps://www.noaa.gov