Lake Oroville Water Operations
The Department of Water Resources (DWR) continues releases from Lake Oroville to manage storage levels along with water quality and flows through the Sacramento-San Joaquin Delta. Total releases to the Feather River amount to 5,500 cubic feet per second (cfs), with adjustments being made as needed. Over the past week, inflows into Lake Oroville have been in the range of 2,800 to 3,900 cfs and are projected to be lower for the coming week.
DWR will use the main spillway for water releases through early next week to manage storage within the Oroville complex and maintain Feather River temperature levels during river valve outlet system work near the Hyatt Powerplant. When the main spillway is not in use water may still be seen on the main spillway outlet as the seals on the eight radial gates are not designed to be watertight. The gate seals do not play a role in the structural integrity of the gates, which continue to operate as intended. DWR periodically maintains and adjusts the seals during low-reservoir conditions to improve their sealing capability. The radial gates were also last inspected and tested in Dec. 2022.
Visitors to Oroville Dam may also notice minor amounts of water flowing from drains built into the emergency spillway. As the reservoir level has increased, water flow from the drains has increased, which is normal and expected with the emergency spillway design. The dam and emergency spillway continue to operate as intended.
Driftwood and other floating debris on Lake Oroville are expected due to continued water inflows from tributaries and a high lake level, in combination with past wildfires impacting the watershed. Since January, DWR and California Department of Parks and Recreation (State Parks) staff have been collecting, containing, and pulling pieces of wood out of the lake and away from boat launch ramps using boom lines. However, boaters, water skiers, and other water recreationists should take precautions when operating boats on Lake Oroville and should remain alert for floating debris.
The Lake Oroville reservoir is the largest storage facility in the State Water Project (SWP) and supports environmental and water delivery needs to 27 million Californians and reduces flood risks to downstream communities. DWR continues to closely monitor lake levels and will adjust releases accordingly to optimize operations for water storage and environmental protection while allowing for carryover storage into next year.
Car-Top Boat Launches
State Parks reopened the Nelson Bar Car-Top Boat Launch this week due to receding water levels at Lake Oroville. The lake has dropped below 891 feet, which has uncovered the parking lot, providing safe vehicle access. The Nelson Bar Car-Top Boat Launch is open daily from 8 a.m. to sunset and is located along the west branch of the north fork arm of Lake Oroville; accessible via Pentz Road and Lime Saddle Road. There are three other car-top boat launches open at Lake Oroville – Vinton Gulch, Stringtown and Foreman Creek.
Supporting Salmon Health
California’s Central Valley is home to four runs of Chinook salmon: spring, fall, late-fall, and winter. From climate change to loss of habitat, salmon are faced with a number of threats, and one of the latest to emerge in recent years is a thiamine deficiency.
Thiamine is vitamin B1, and it is a crucial vitamin for neurons and immune systems in salmon. Evidence of a thiamine deficiency in spring-run salmon started showing up in 2019. Salmon typically get adequate levels of thiamine from their food supply in the ocean, but for the last several years that hasn’t been happening due to changes in the ocean food web.
Spring-run are unique from other runs of salmon because they return to rivers in the spring and spend the summer in cold water pools before spawning early in the fall. In the Feather River, many of these fish enter the Feather River Fish Hatchery, where they are tagged for identification and released back into the river. In 2021, DWR started injecting these fish with thiamine as they passed through the hatchery in order to decrease thiamine-related mortality of their offspring.
Visit our YouTube channel for a video about DWR’s collaboration to help spring-run Chinook salmon.
A Restorative Winter
At only 29 percent capacity in December 2022, the Lake Oroville reservoir has made an astounding recovery thanks to numerous atmospheric rivers that delivered heavy amounts of rain and snow to California this winter. Lake Oroville gained more than 2.5 million acre-feet of water after Dec. 1, bringing the reservoir to its full capacity – a marked difference in just seven months.
See the difference in water levels between Dec. 21, 2022, when the reservoir was at 29 percent capacity, to July 3, 2023, with Lake Oroville at 99 percent capacity. It’s a welcome sight!
A full reservoir delivers numerous opportunities for water recreation at Lake Oroville and is also a prime location to beat 100-degree weather. Water enthusiasts were out in full force at Lake Oroville during the week of July 4. Whether you enjoy swimming, boating, kayaking, jet skiing, fishing or several other water activities, don’t miss your opportunity to relax and recreate at the lake! The marinas at Bidwell Canyon and Lime Saddle are open daily and provide a variety of services such as a shuttle and boat rentals.
DWR, State Parks, and the California Department of Fish and Wildlife also maintain over 92 miles of trails in the Oroville area. An interactive map of recreation facilities, including open boat ramps, 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 Visitor Center.
The Lake Oroville Visitor Center is open Monday through Friday between 9 a.m. and 5 p.m. The Visitor Center offers numerous educational exhibits, a theater featuring videos about the building of Oroville Dam, walking and hiking trails, and a 47-foot-tall observation tower providing unsurpassed panoramic views.
Current Lake Operations
Lake Oroville is at 890 feet elevation and storage is approximately 3.38 million acre-feet (MAF), which is 96 percent of its total capacity and 137 percent of the historical average.
Feather River releases are at 5,500 cfs today to meet downstream Delta water quality and outflow. Flows through the City of Oroville are at 1,700 cfs and releases from the Thermalito Afterbay Outlet (Outlet) are at 3,800 cfs for a total of 5,500 cfs downstream of the Outlet. DWR continues to assess releases to the Feather River 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 7/20/2023.