Lake Oroville Update - June 6, 2025

Golden Mussel Inspection Program 

DWR’s mussel inspection program in Oroville is underway to protect State Water Project (SWP) infrastructure. Mandatory watercraft inspections are required prior to launching at the Oroville Facilities (Lake Oroville, Thermalito Forebay, Thermalito Afterbay). Watercraft that pass the inspection will receive a seal and can launch during designated ramp hours.       

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.   

Watercraft inspections and decontamination services at DWR’s Oroville facilities are free. To pass an inspection, watercraft and trailers must not have any attached mussels and be clean and 100 percent dry. Watercraft with ballast bags/tanks, bilge, and motors must have a working battery and be operational to complete required inspections. Be sure to bring your vessel’s keys! 

Sealed Vessel Launching   

All trailered and personal watercraft with an intact blue seal 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.      

Lake Oroville   

Ramp hours: Daily from 7:30 a.m. to 10 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 one hour after sunset 

• Monument Hill  

Thermalito Forebay  

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

• North Forebay (Non-motorized vessels only)  

More details about DWR’s mussel inspection program are available at water.ca.gov/mussels.  

CAL FIRE Burning Grasses Around Thermalito  

For the fifth straight year, CAL FIRE Butte County, DWR, and the California Department of Parks and Recreation (State Parks) are conducting a series of prescribed burns around the Thermalito Forebay and Afterbay. Prescribed burning is continuing June 9-10 at the North Thermalito Forebay along Garden Drive and South Thermalito Forebay along Grand Avenue.  

DWR’s Thermalito Vegetation Management Project was first conducted in 2021 to improve valley grassland and vernal pool habitat. Invasive annual grasses and other invasive species like the yellow starthistle degrade native grasslands and fire is a valuable tool to combat this degradation. Because invasive species have abundant seeds and dry material called thatch that build up on the soil, it is important to burn the same area multiple years in a row. When completed during the right stage in these species' growth cycle, the prescribed burns eradicate the current crop, reduce the dry residual thatch, and decrease the spread of seeds. The area has seen a significant decline in the volume of invasive grasses and starthistles since the project began. The burns also allow DWR to continue post-fire studies on vernal pool habitat.  

Oroville Dam Citizens Advisory Commission 

The California Natural Resources Agency is hosting its 20th Oroville Dam Citizens Advisory Commission meeting on Friday, June 13 from 10 a.m. to noon. The virtual public meeting will include presentations and an opportunity for public comment. Presentations will cover advancements in research on atmospheric river, snowpack, and storm runoff forecasting (recently documented in the Yuba-Feather Forecast-Informed Reservoir Operation (FIRO) Final Viability Assessment) and how this may inform the future update of the U.S. Army Corps of Engineers’ Oroville Water Control Manual; an explanation of how the California Nevada River Forecast Center forecasts inflow to California reservoirs; and an update on the Commission’s 2025 Legislative Report.  

The Citizens Advisory Commission is a forum for questions and feedback from communities surrounding Oroville Dam. For information about the meeting, please visit the Oroville Dam Citizens Advisory Commission website. 

Project Upgrading Power and Fiber Communication Lines 

DWR is starting construction on a project to replace power and fiber optic communication lines that support the Hyatt Powerplant and Thermalito Diversion Dam Facilities. Starting Monday, June 9, construction crews will begin clearing and grubbing trees and vegetation near the Lakeland Boulevard Trailhead access point. Vegetation work is anticipated to last approximately three weeks.  

During construction, portions of the Dan Beebe and Brad Freeman Trails near the Diversion Pool will remain closed for the safety of the public. Trails in this area are expected to remain closed for approximately one year during power and fiber optic line upgrades.   

Oroville Recreation  

Between Jan. 30 and April 20, higher flows in the Feather River required the temporary removal of sensitive fish monitoring equipment or may have impacted counting operations. Upstream migrating fish totals through the Feather River Fish Monitoring Station between Jan. 1 and June 1, 2025 are:    

• Spring-run Chinook salmon: 14,881 

• Steelhead: 160 

• To see previous year data, visit CalFish.org.  

Current Lake Operations 

Lake Oroville is at 899 feet elevation and storage is approximately 3.42 million acre-feet (MAF), which is 100 percent of its total capacity and 122 percent of the historical average.  

Feather River flows are at 950 cfs through the City of Oroville with 1,850 cfs being released from the Thermalito Afterbay River Outlet (Outlet) for a total Feather River release of 2,800 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 6/5/2025. 

###  

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