Lake Oroville Update - May 14, 2025

Watercraft Inspection Program at DWR’s Oroville Facilities    

With the discovery of the highly invasive golden mussel in California waterways, DWR is starting a mussel inspection program in Oroville to protect State Water Project (SWP) infrastructure. Starting Monday, May 19, mandatory watercraft inspections will be required prior to launching at the Oroville Facilities (Lake Oroville, Thermalito Forebay, Thermalito Afterbay). One of DWR’s primary responsibilities is to maintain the SWP and its associated storage, conveyance, flood protection, and power generation facilities that deliver water to 27 million Californians and approximately 750,000 acres of farmland annually. DWR’s Upper Feather River and Lake Oroville reservoirs provide water to several municipal water agencies, produce hydroelectric power generation, and provide flood control. These reservoirs also supply water to the Feather River Fish Hatchery, which critically supports Central Valley and Pacific Ocean salmon fisheries and is one of the most productive hatcheries on the west coast.  

DWR recognizes the impact this will have on boaters and recreation users at Lake Oroville and is not closing the reservoir to implement a mussel inspection program. DWR aims to minimize recreation impacts by keeping Lake Oroville open and implementing an inspection program before Memorial Day, one of the most popular holidays for outdoor recreating. Ahead of Memorial Day weekend, DWR encourages watercraft owners to take advantage of early inspection and decontamination opportunities and have their vessel sealed to be ready to launch for the holiday weekend.  

DWR is not the only reservoir operator in California to implement a watercraft inspection program this year to protect reservoir infrastructure. Due to their water chemistry, many reservoirs in northern California are suspectable to golden mussel invasion including Folsom Lake.  

Starting May 19, all trailered vessels and personal watercraft launching at DWR’s Oroville Facilities will require a properly attached seal - a wire with a blue-colored tag specific to the Oroville Facilities that connects the watercraft to the trailer or, in the case of a jet ski, seals the steering unit to the back of the vessel. Once the seal is connected, it cannot be removed without cutting the wire so seal checkers at designated boat ramps will know that the vessel has not been launched elsewhere since being sealed. This prevents watercraft users from launching in an infested waterbody and unintentionally transporting mussels or their larvae. Records will be kept of each inspection and will include the date, seal number, watercraft CF number, and trailer license plate number.       

Blue Oroville launch seals will only be applied if the watercraft passes inspection. To pass inspection:  

1. Mussels cannot be present.    

2. All water-containing areas of the watercraft and trailer must be 100 percent dry. This includes, but is not limited to, the live well, bilge, ballast tanks, cup holders, low depressions in the hull, anchor storage area, coolers, life jackets, bait buckets, ropes or lines, or any area in the watercraft or trailer that can hold water.   

To avoid inspection failure, follow these steps before arriving at the Inspection Station:    

• Clean off aquatic plants, animal material, mud, dirt, and other debris from your watercraft, trailer, and equipment.     

• Drain the ballast, bilge, live-wells, and other water-containing areas of the vessel.    

• Dry water-containing areas of the watercraft, trailer, and equipment, including bilge, interior, hull, live well, and other areas where water could collect.  

Early Inspection and Launch Seal Opportunity  

North Thermalito Forebay at Garden Drive and HWY 70 in Oroville   

Hours of operation starting Friday, May 16: 8:30 a.m. to 5:30 p.m.  

Vessel owners may volunteer to have their watercraft inspected and sealed prior to the start of the mandatory watercraft inspection program which begins Monday, May 19, 2025. Watercraft that pass inspection will receive a blue Oroville launch seal and be permitted to launch when the mandatory program begins on May 19, 2025. A DWR Decontamination Station will be available to decontaminate a limited number of boats. The intent is to reduce the amount of congestion that may occur once the mandatory program begins on May 19.  

NOTE: Between Friday, May 16 and Sunday, May 18, inspection staff will not be at boat ramps to provide an Oroville re-entry seal when leaving. It is recommended that watercraft that pass an inspection during this period wait to launch at the Oroville facilities until the mandatory inspection program begins on May 19.   

Watercraft Inspection Location  

North Thermalito Forebay at Garden Drive and HWY 70 in Oroville   

Hours of operation: Daily from 8:30 a.m. to 5:30 p.m.  

Watercraft inspections at DWR’s Oroville facilities will be free. Watercraft that pass inspection will be sealed with a blue Oroville launch seal and permitted to launch at the three Oroville reservoirs. Available boat ramps and hours of operation are provided below. Vessels that fail inspection can undergo decontamination or return for a follow-up inspection the next day but must be clean and 100 percent dry.  

Decontamination Services   

North Thermalito Forebay at Garden Drive and HWY 70 in Oroville   

Hours of operation: Daily from 8:30 a.m. to 5:30 p.m.   

Watercraft with ballast tanks or other components that cannot be drained will automatically fail an inspection. Owners have the option to have their vessel decontaminated at a DWR-designated decontamination station where these water-containing areas will be flushed with hot (120 F) water to kill mussels and their larvae. Watercraft will then receive a blue Oroville seal and may launch immediately if desired.  

If a boat owner chooses not to have their vessel decontaminated, the vessel can be sealed with a red quarantine tag and will not be permitted to launch at the Oroville facilities for a minimum of 30 days. After completing the 30-day quarantine period, the vessel is eligible for launching.  

Sealed Vessel Launching   

All trailered and motorized watercraft with an intact blue seal and watercraft with a red seal that have not launched for 30 days will be permitted to launch at the following boat ramp facilities during the hours listed. Boat ramps at the Oroville facilities will no longer be open 24/7. Launching trailered boats or personal watercraft is not allowed at any other location.      

When a vessel is leaving the Oroville facilities, staff at designated launch ramps will offer to re-seal all departing watercraft with a blue Oroville seal. During the next visit, sealed Oroville vessels can proceed directly to the ramp for launching where a seal checker will remove the seal. Reinspection is not required as long as the seal is not broken.   

Launching Locations and Hours  

Starting May 19, 2025, the launching of sealed watercraft will be limited to the following locations and hours.   

Lake Oroville   

Ramp hours: Daily from 7:30 a.m. to 7:30 p.m.    

• Lime Saddle  

• Loafer Point   

• Spillway      

Extended Ramp hours: Daily from 5 a.m. to 10 p.m.    

• Bidwell Canyon   

Thermalito Afterbay   

Ramp hours: Daily from 7:30 a.m. to 9:30 p.m.   

• Monument Hill  

Thermalito Forebay  

Ramp Hours: Daily from 7:30 a.m. to 7:30 p.m.  

• North Forebay (Non-motorized vessels only)  

DWR is assessing opportunities to increase boat ramp operation hours or open additional ramps for trailered or personal watercraft launching. Physical barriers will be placed at all other launch locations and only hand-launching of boats will be allowed.  

Reduced Ramp Hours for Launching/Retrieving Trailered or Personal Watercraft   

While Lake Oroville will remain open 24/7 for recreation, boat ramps will have limited hours of operation and will be closed at night to watercraft launching and retrieving. The marinas at Lake Oroville provide overnight moorings. This provides boaters the option to remain on the lake after the ramps close for the night. For more information, contact the marinas - Bidwell Canyon or Lime Saddle.   

Re-entry seals will only be offered to departing vessels during ramp hours. Please plan ahead.   

Inspection Failure due to Visible Mussels   

Any watercraft with visible mussels will automatically fail, receive a red seal, and be reported to the California Department of Fish and Wildlife (CDFW) for a mandatory decontamination and quarantine period. These vessels will not be permitted for re-inspection or launching at the Oroville facilities without approval from CDFW.     

For more information about invasive mussels, visit https://water.ca.gov/mussels.  

### 

Know someone who would like to receive Community Updates? They can email their request to oroville@water.ca.gov.