No More Boat Inspections at This Major Northern California Lake; Here’s What Changed

Mussel checks at Lake Oroville, the Thermalito Forebay, and the Thermalito Afterbay has been halted, the California Department of Water Resources (DWR) announced.

Starting April 29, boats would no longer need inspection, cleaning, or special seals. People can remove the blue seals themselves, and there would be no inspectors at boat ramps.

Boat launch areas that were closed will reopen. Some may take a little time to fully open. At Lake Oroville, boats can launch any time, day or night.

Reason For This Change

According to the DWR, it began conducting checks in May 2025 to stop the spread of golden mussels. The risk, now, has become lower than expected, the department stated.

Studies have shown the water is often too cold for the mussels to grow and spread easily. These mussels need warm water to survive and reproduce. At Lake Oroville, this only happens near the surface.

Cold water, deep lake levels, and dam releases also make it hard for mussels to survive. So far, no golden mussels have been found at these sites.

DWR will still keep testing the water and checking for mussels.

Where Were the Mussels First Found?

Golden mussels were first found in North America in October 2024 in the Sacramento-San Joaquin Delta, according to the California Department of Fish and Wildlife.

Following this, they cropped up in more places in the Delta and nearby water systems. This included water plants, canals, and forebays connected to the State Water Project.

Some places found only a few mussels, while others found many. This raised concerns about damage to water systems and the environment.

What’s Next?

Even though inspections have stopped at Oroville, DWR is still working with the California Department of Fish and Wildlife and California Department of Parks and Recreation to track and control the spread.

Boaters are still asked to clean their boats and gear, drain all water, let everything dry before using it in another lake or river. According to authorities, these steps help stop the spread of invasive species.