Lake Oroville Update - May 31, 2024

DWR Maintaining Storage Capacity at Lake Oroville

The Department of Water Resources (DWR) continues to maintain Lake Oroville at its peak storage capacity while adjusting water releases as needed to account for increasing or decreasing inflows into the reservoir and maintaining flood protection for downstream communities. Releases are closely coordinated with the U.S. Army Corps of Engineers and other water operators and adjusted as needed to maintain balance throughout the water system. DWR continues to monitor Lake Oroville levels to optimize water storage while meeting environmental requirements and allowing for carryover storage into next year.  

 

With Lake Oroville at full capacity, windy periods are likely to cause water to splash onto and over the crest of the emergency spillway. This will result in minor surface wetting of the downstream side of the emergency spillway crest and the very upper sections of the splash pad. Visitors to Oroville Dam may also notice minor amounts of water flowing from drains built into the emergency spillway. Both conditions are normal and expected given the emergency spillway design. The dam and emergency spillway continue to operate as intended.

 

The information below reflects current reservoir level estimates. Forecasts can change quickly and may affect the estimates provided.

 

• Current Oroville Reservoir Level: 899 feet elevation
• Current Storage Capacity: 100 percent
• Total Releases to the Feather River: 3,600 cubic feet per second (cfs)

 

Total releases to the Feather River amount to 3,600 cfs with 650 cfs being routed down the Low Flow Channel through the City of Oroville. An additional 2,950 cfs is being released from the Thermalito Afterbay River Outlet, located 5 miles downstream from Oroville. DWR continues to assess Feather River releases daily.

 

As the largest storage facility in the State Water Project, Lake Oroville helps provide water to 27 million Californians and 750,000 acres of farmland, while providing flood protection to downstream communities along with environmental and recreation benefits. Spring is an important time for water project operators to fill reservoirs like Lake Oroville ahead of dry months. It also is an important migration window for many native fish species. DWR is using the best available science to protect fish species. However, SWP operations have faced significant restrictions in the Delta this year that have impacted the ability to capture and store the water needed if California sees a return to drought conditions.

 

Prescribed Burns Scheduled Next Week

For the fourth straight year, DWR, CAL FIRE/Butte County Fire Department, and the California Department of Parks and Recreation (State Parks) will conduct a series of prescribed burns throughout the Thermalito Forebay and Thermalito Afterbay for vegetation management. The first prescribed burn is scheduled Wednesday, June 5 and will target approximately 100 acres along South Wilbur Road near the Afterbay. During the burn, a portion of Wilbur Road will be closed south of State Highway 162 due to low visibility and for the safety of fire crews. Further prescribed burns around the Forebay and Afterbay are also planned for June 20 and June 21. Burn activities are dependent on favorable weather conditions with the schedule subject to change.

 

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.

 

Upcoming prescribed burns also have the added benefit of reducing dry brush near the Thermalito Forebay in preparation for the City of Oroville’s Fourth of July fireworks showcase. Smoke from prescribed burning activities will be highly visible in the Oroville area in the coming weeks.

 

Oroville Recreation

DWR, State Parks, and the California Department of Fish and Wildlife (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 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.

 

Lake Oroville is one of the State Water Project’s premier recreational destinations and one of California’s best fishing spots. The lake provides both warm-water and cold-water fisheries and is a popular destination for bass tournaments. Below the Oroville Dam, the Thermalito Afterbay and the Feather River offer additional excellent fishing opportunities. The marinas at Bidwell Canyon and Lime Saddle are open daily and provide a variety of services including a convenience store, gas, and boat rentals.

 

Upstream migrating fish totals through the Feather River Fish Monitoring Station between Jan. 1 and May 26 are:  

• Spring-run Chinook salmon: 4,021
• Fall-run Chinook salmon: 42
• Steelhead: 839
• Due to higher flows in the low-flow channel of the Feather River between Feb. 26 and March 18, some fish swam over the monitoring station and were not counted in upstream migration totals.

 

Current Lake Operations

Lake Oroville is at 899 feet elevation and storage is approximately 3.53 million acre-feet (MAF), which is 100 percent of its total capacity and 125 percent of the historical average.

 

Feather River flows are at 650 cfs through the City of Oroville with 2,950 cfs being released from the Thermalito Afterbay River Outlet (Outlet) for a total Feather River release of 3,600 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 midnight 5/30/2024.

 

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