Lake Oroville Update - June 20, 2025

Prescribed Burns Anticipated Next Week 

CAL FIRE, in partnership with the Department of Water Resources (DWR) and the Department of Parks and Recreation (State Parks), is planning a prescribed burn next Tuesday, June 24, in the Loafer Creek Recreation Area near the Loafer Creek boat ramps and Day Use Area. To ensure public safety, the Day Use Area and nearby trails within the prescribed burn units will be temporarily closed during burn operations. Trail users should be cautious when recreating near work areas, obey all posted signage, and avoid active work zones. Smoke will be visible in the Oroville area during and after the burn. Prescribed burn operations are weather-dependent and may be rescheduled if conditions are not favorable.  

Over the past few weeks, the Butte County Sheriff’s Office (BCSO) and CAL FIRE have been preparing the burn units by trimming lower branches on trees and shrubs and creating small burn piles. These efforts help reduce fuel and promote a lower-intensity fire, which supports both safety and the health of the oak woodland ecosystem. Following the prescribed burn, crews will remain on-site to monitor conditions, extinguish any remaining hot spots, and continue creating small burn piles. These piles will be safely burned during the fall or winter months. 

DWR appreciates the public’s cooperation and understanding as we work to reduce wildfire risk, increase public safety, and support long-term land management goals. Vegetation management remains a top priority for DWR and its partners, including CAL FIRE, the Butte County Fire Department, BCSO, State Parks, the California Conservation Corps (CCC), the California Dept. of Fish and Wildlife (CDFW), local tribes, and the Butte County Fire Safe Council. 

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.    

• Spillway    

• Bidwell Canyon 

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

• Lime Saddle 

• Loafer Creek  

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.  

Spring-Run Chinook Salmon Mortality in the Feather River   

DWR is committed to the health and survival of California fish populations, which continue to be impacted by climate and ocean food supply changes. During high fish return periods in the Feather River, DWR environmental scientists perform regular monitoring surveys to track fish mortality. For the last two years, DWR scientists have observed increased spring-run Chinook abundance in the Feather River and, unfortunately, increased salmon mortality, which is unusual as spring-run mortality in the summer is generally low. Mortalities normally occur in the late summer and fall, when spawning begins. 

In 2024, DWR coordinated with the California Department of Fish and Wildlife (CDFW) to collect samples for pathology analysis and determined spring-run Chinook were infected with Columnaris, a bacterial infection that affects freshwater fish. It is believed Columnaris is once again causing increased fish mortality rates this spring.  

DWR’s Feather River Fish Monitoring Station has counted more than 17,000 spring-run Chinook salmon returning to spawn this year, the best return since 2013, with more fish passing the structure daily. The monitoring station began operating in September 2023 to accurately track the arrival timing, number, species, and origin (naturally or hatchery raised) of returning salmon and steelhead. As fish migrate up the river, they pass through the monitoring station that spans the river channel and contains chutes with underwater cameras that capture video of fish using motion detection software. Upstream migrating spring-run are not handled at the fish monitoring station.  

Since the installation of the monitoring station, numerous fish species have successfully passed through the fish monitoring station to migrate further up the Feather River. Population data for the Feather River Fish Monitoring Station is publicly available and updated regularly on CalFish.org.  

• 2023 Fall-run Chinook salmon (September – December): 31,125 

• 2024 Spring-run Chinook salmon: 7,115 

• 2024 Fall-run Chinook salmon: 40,338 

• 2024 Steelhead trout: 1,990 

• 2025 Spring-run Chinook salmon (ongoing): 17,235 

DWR has observed deceased spring-run Chinook salmon collecting on the Feather River Fish Monitoring Station, located near the bottom of the low flow channel. Moribund fish are also observed holding just upstream of the weir. These fish have already migrated upstream, most to the Feather River Fish Hatchery, but have dropped back downstream due to their weakened state. Any deceased fish floating downstream would be expected to wash up on the weir as the monitoring station naturally collects debris, including dead fish and vegetation, moving downstream. The monitoring station does not prevent fish from traveling upstream or downstream.  

Though spring-run are migrating upstream to hold over-summer in the deep, cold pools of the low flow channel, some fish have been observed going downstream through the monitoring station. Only net counts of fish passing upstream of the fish monitoring station are updated on CalFish.  

Spring- and fall-run Chinook salmon are successfully migrating up the Feather River to the Feather River Fish Hatchery, where they are tagged and spawned to support Central Valley and Pacific Ocean populations. DWR and CDFW continue to meet and exceed Hatchery production goals for Chinook salmon and steelhead trout, even with recent drought impacts.  

The Department also continues to maintain compliance with Feather River water temperature regulations required by the CDFW and the National Marine Fisheries Service for the health of fish populations. In fact, water temperatures in the Feather River this spring have met or been colder than required regulations.  

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 15, 2025 are:    

• Spring-run Chinook salmon: 17,235 

• Steelhead: 171 

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

Current Lake Operations 

Lake Oroville is at 894 feet elevation and storage is approximately 3.34 million acre-feet (MAF), which is 98 percent of its total capacity and 122 percent of the historical average.  

Feather River flows are at 850 cfs through the City of Oroville with 3,650 cfs being released from the Thermalito Afterbay River Outlet (Outlet) for a total Feather River release of 4,500 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 6/19/2025. 

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