Lake Oroville Update - November 7, 2025

Spillway Maintenance Activities

In early October, the Department of Water Resources (DWR) completed routine annual cleaning and inspections of Oroville Dam’s main spillway chute to assess the condition of the spillway’s concrete slabs, walls, joint sealant, and dentates (energy dissipators at the base of the spillway structure). Following inspections, minor concrete repairs, slab epoxy coating, and joint sealant work were identified in localized areas of the spillway. Maintenance activities are nearing completion with work expected to finish around Nov. 15 depending on weather conditions.

While the main spillway continues to perform well and operate as designed, periodic concrete and sealant repairs of the spillway are expected due to seasonal temperature variations, spillway releases, and sun exposure. The spillway was rebuilt to the highest engineering and safety standards with oversight and guidance by the Federal Energy Regulatory Commission (FERC), the Division of Safety of Dams (DSOD), and an independent board of consultants. DWR performed a significant amount of inspection and testing throughout construction to verify compliance with project specifications. DWR also provides regular updates to the Oroville Dam Citizens Advisory Commission, a public forum for discussing operations, maintenance, and public safety activities at Oroville Dam and its facilities.

Salmon Spawning Operations

DWR and the California Department of Fish and Wildlife (CDFW) continue spawning activities for fall-run Chinook salmon at the Feather River Fish Hatchery in Oroville. As part of their two- to five-year lifecycle, fall-run Chinook salmon traditionally migrate from the Feather River to the ocean and later return to the Feather River to spawn. Fall-run salmon typically start returning as early as July and continue through November. Many make their way to the Hatchery, where CDFW staff, in coordination with DWR, process salmon by collecting, fertilizing, incubating their eggs, then raising and releasing fish. 

Chinook salmon raised at the Feather River Fish Hatchery will later be released in Lake Oroville, the Feather River, and San Francisco Bay to support inland and ocean fisheries. In addition, DWR and CDFW continue thiamine treatments to combat B1 vitamin deficiencies. This treatment improves the health of the fish, increasing the survival of Chinook salmon from egg to juvenile.

Oroville Recreation Advisory Committee

The Oroville Recreation Advisory Committee (ORAC) met Nov. 7 at the Oroville Southside Community Center. ORAC was established by the Federal Energy Regulatory Commission (FERC) to review and provide recreation plan recommendations for Oroville Facilities owned by DWR. The 13-member committee is made up of representatives from state and local government, recreation groups, and business and community organizations. To obtain a summary of the meeting, send a request to oroville@water.ca.gov. 

Paving and Sealing Work Ongoing

DWR continues work on a paving and sealing project to rehabilitate several locations owned and maintained by the department that are heavily used by maintenance staff and members of the public. While improvements in most public areas have been completed, portions of the Thermalito Afterbay Dam Crest Road remain closed for ongoing pavement work. Vintage Paving Company, Inc. of Winters, Calif. is the project contractor.

Upcoming construction work will require closures to the following public areas and roads:

• Aug. 18 – Nov. 30: Afterbay Dam Crest Road/Brad Freeman Trail south of State Route 162 to the East Hamilton Road Trail Access
• Nov. 17: Canyon Drive from the four-way intersection at Oroville Dam Blvd. E./Royal Oaks Drive to Royal Oaks Drive near the Upper Overlook will have one-way traffic control from 6:30 a.m. to 6:30 p.m. for striping work

Additional locations for future paving and sealing work include:

• Thermalito Diversion Dam Powerplant

• Oroville Field Division Operations and Maintenance Center at Glen Drive

DWR will provide more details about scheduled work and potential public access impacts in future newsletters. Work schedules are subject to change based on weather and the availability of equipment and materials.

Golden Mussel Inspection Program

DWR is reminding the public that boat ramps at Lake Oroville are no longer open 24/7. Watercraft must be out of the water by ramp closing time or they will be locked into the facility overnight. Please plan ahead. More details about DWR’s mussel inspection program are available at water.ca.gov/mussels.

Watercraft Inspection Location/Decontamination Services

North Thermalito Forebay at Garden Drive and HWY 70 in Oroville 

Hours of operation: Daily from 8:30 a.m. to 4:30 p.m.

Sealed Vessel Launching 

Lake Oroville

Ramp hours: Daily from 7:30 a.m. to 6:30 p.m.

• Spillway  

Ramp hours: Monday-Thursday 7:30 a.m. to 6:30 p.m.; Friday-Sunday 7:30 a.m. to 8 p.m.

• Bidwell Canyon

Ramp hours: Monday-Thursday 5 a.m. to 6:30 p.m.; Friday-Sunday 5 a.m. to 8 p.m. 

• Lime Saddle

Ramp hours: Daily from 5 a.m. to 6:30 p.m.

• Loafer Creek/Loafer Point

Thermalito Afterbay 

Ramp hours: Daily from 1.5 hours before sunrise to 1 hour after sunset

• Monument Hill

Thermalito Forebay

Ramp Hours: Daily from 8 a.m. to sunset

• North Forebay (Non-motorized vessels only)

Oroville Recreation

DWR, the Department of Parks and Recreation (State Parks), and CDFW maintain over 92 miles of trails in the Oroville area. An interactive map of recreation facilities, including open trails and their permitted uses (hike, bike, horse, multi), is available on DWR’s Lake Oroville Recreation webpage. A paper trail map is available at various locations, including most entrance kiosks and the Lake Oroville Visitor Center. 

Staffed by knowledgeable guides, the Lake Oroville Visitor Center features interpretive displays on Oroville Dam, area geology, wildlife and habitat, hydroelectric power, and cultural and historical artifacts. View videos in the theater about the construction of Oroville Dam, walk or hike along nearby trails, and visit the 47-foot-tall observation tower that provides unsurpassed panoramic views of surrounding areas. Free guided tours for school and community groups are available by reservation. Parking and admission to the Visitor Center are free.

Between Jan. 30 and April 20, high flows in the Feather River required the temporary removal of fish monitoring equipment resulting in lower spring-run estimates. Upstream migrating fish totals through the Feather River Fish Monitoring Station between Jan. 1 and Nov. 3, 2025 are:  

• Spring-run Chinook salmon (April 16 through June 30): 17,712
• Fall-run Chinook salmon (July 1 through present): 39,587
• Steelhead: 1,040
• To see previous year data, visit CalFish.org.

Current Lake Operations

Lake Oroville is at 772 feet elevation and storage is approximately 1.80 million acre-feet (MAF), which is 53 percent of its total capacity and 100 percent of the historical average.

Feather River flows are at 650 cubic feet per second (cfs) through the City of Oroville with 1,800 cfs being released from the Thermalito Afterbay River Outlet (Outlet) for a total Feather River release of 2,450 cfs downstream. DWR continues to assess Feather River releases daily.

The public can track precipitation, snow, reservoir levels, and more at the California Data Exchange Center. The Lake Oroville gage station is identified as “ORO.”

All data as of 11:59 p.m. on 11/6/2025.