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Oroville Spillway Incident

A steady barrage of storms in early 2017 resulted in serious damage to the Lake Oroville spillways. This included a concrete failure on the lower chute of the gated flood control spillway, severe erosion under the gated spillway, and erosion in the areas on the hillside beneath the emergency spillway.

Oroville Dam Remains Safe, Fully Operational

DWR has successfully managed outflow and Lake Oroville levels while crews work 24 hours a day to repair erosion areas, place large rocks and pour concrete into the eroded gullies, remove large amounts of eroded debris, and construct or improve access roads.

We're also actively monitoring the status of the Oroville Dam, the gated flood control and emergency spillways, Hyatt Powerplant, related structures, and progress of emergency response and repair activities. This work will continue throughout the spring, summer, and into the fall of 2017 to ensure both spillways are safe to operate by the next flood season.

Read more about the spillway recovery effort.

Record Rainfall

The efforts and achievements above occurred following the wettest January and February in 110 years of Feather River hydrologic record. Lake Oroville received an entire year’s average runoff of 4.4 million acre-feet in about 50 days during those two months.

This winter over 3.6 million acre-feet volume of reservoir inflow (equivalent to the entire storage capacity of Lake Oroville) has been safely released from Lake Oroville through the significantly damaged gated flood control spillway.

Collaborative Operations

Full state, federal, and local resources have been marshaled to help manage Lake Oroville operations, assess the problems, and rapidly fix them. Dam experts with the U.S. Army Corps of Engineers, Federal Energy Regulatory Commission Dam Safety, the California Division of Safety of Dams, and independent dam safety engineers remain actively engaged in managing the situation. Public safety is DWR’s top priority.