Lake Oroville Update - September 19, 2025

Routine Spillway Cleaning and Inspections Upcoming

Following another wet winter requiring flood control releases from Oroville Dam's main spillway, the Department of Water Resources (DWR) will perform cleaning and conduct routine annual inspections of the concrete spillway chute starting the week of Sept. 22. Members of the public should expect to see crews using pressure washers, brooms, and small cleaning equipment, followed by engineers traversing the spillway on foot conducting the inspections through Oct. 10.

Annual inspections of the main spillway are conducted by DWR engineers. During the inspections, engineers assess the condition of the spillway's concrete slabs, walls, joint sealant, and dentates (energy dissipators at the base of the spillway structure). Routine maintenance activities are expected this fall based on inspection results and reservoir levels.

The main spillway continues to perform well and operate as designed. The spillway was rebuilt to the highest engineering and safety standards with oversight and guidance by the Federal Energy Regulatory Commission (FERC), 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.

Lakeside Access Road to Open

Lake Oroville's water elevation has lowered enough to allow DWR to reopen the Lakeside Access Road on Thursday, Sept. 25, providing daily access to the Spillway Boat Ramp and Day Use Area between 7:30 a.m. and 9 p.m. These hours are consistent with DWR's invasive mussel screening program. Construction of Lakeside Access Road was completed in 2022 and provides a direct route to the Spillway Day Use Area from Oroville Dam Crest Road without requiring visitors to pass through California Highway Patrol (CHP) screening. The CHP kiosk will now be closed with Lakeside Access Road's reopening.

Oroville Salmon Festival

Join DWR at the Oroville Salmon Festival on Saturday, Sept. 27! Visit our booth at the Feather River Fish Hatchery from 9 a.m. to 3 p.m. We will have educational materials on water safety, a salmon gyotaku fish printing activity, and a photo opportunity. DWR Guides will also be giving free tours of the Hatchery, where DWR and the California Department of Fish and Wildlife (CDFW) raise Chinook salmon and steelhead to improve fish populations throughout the state.

Other Salmon Festival activities include Motor Mania, Salmon Run, a food and beer garden, Kid's Zone, and numerous shopping opportunities and vendor booths in downtown Oroville. DWR has also partnered with the Oroville State Theater to showcase videos about efforts to support vital salmon habitat restoration, fish health, and population growth.

View the full Salmon Festival schedule at Visit Oroville.

Paving and Sealing Work Ongoing

DWR continues work on a $1.9 million paving and sealing project to rehabilitate seven locations owned and maintained by the department that are heavily used by maintenance staff and public members. Project work is expected to continue through November 2025. Vintage Paving Company, Inc. of Winters, Calif. is the contractor for the project.

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

• Aug. 18 - Sept. 30: Afterbay Dam Crest Road/Brad Freeman Trail south of State Route 162 to the East Hamilton Road Trail Access

Additional locations for future paving, sealing, and guardrail work include:

• Thermalito Powerplant Access Roads
• Thermalito Diversion Dam Powerplant

• Oroville Field Division Operations and Maintenance Center at Glen Drive
• Canyon Drive from the intersection of Oroville Dam Blvd. E./Royal Oaks Drive heading north to the dam and upper overlook
• Oroville Dam Boulevard East near Oro Powerhouse Road

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

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 5:30 p.m.

Sealed Vessel Launching

Lake Oroville

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

• Spillway
• Bidwell Canyon

Extended Ramp hours: Daily from 5 a.m. to 9 p.m.

• Lime Saddle
• Loafer Creek

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)

Feather River Fish Monitoring Station

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 Sept. 16, 2025 are:

• Spring-run Chinook salmon (April 16 through June 30): 17,737
• Fall-run Chinook salmon (July 1 through present): 1,056
• Steelhead: 235
• To see previous year data, visit CalFish.org.

Current Lake Operations

Lake Oroville is at 808 feet elevation and storage is approximately 2.19 million acre-feet (MAF), which is 64 percent of its total capacity and 111 percent of the historical average.

Feather River flows are at 650 cubic feet per second (cfs) through the City of Oroville with 4,350 cfs being released from the Thermalito Afterbay River Outlet (Outlet) for a total Feather River release of 5,000 cfs downstream. On Saturday, Sept. 20, flows from the Outlet will increase to 4,850 cfs by 11 a.m. with total Feather River releases increasing to 5,500 cfs. On Sunday, Sept. 21, flows from the Outlet will increase to 5,350 cfs by 11 a.m. with total Feather River releases increasing to 6,000 cfs. 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 9/18/2025.