Safety reviews of Oroville Dam's emergency spillway relied on two unpublished studies by the Department of Water Resources' Division of Engineering.

San Luis Dam is known to need an operating restriction of at least 50 feet to be within Reclamation's Dam Safety Public Protection Guidelines. However, because the dam is operated by the California Department of Water Resources, there appears to have been no formal consideration of an interim operating restriction to protect lives and property. The reservoir is full and is currently endangering over 200,000 people.

FERC records show the Department of Water Resources repaired 7,000 square feet of Oroville dam's main spillway in 2009, including injecting epoxy resin into large cracks.

As of Saturday, February 11 2017, the crisis with the damaged main spillway at Oroville is continuing to unfold. The reservoir  began to spill over the 1,703 foot auxiliary spillway lip this morning, and as of 2:00 pm, the California Data Exchange Center elevation sensor shows 0.9 feet of flow over the spillway lip. Engineers for the Department … Continue reading Oroville’s auxiliary spillway – crisis engineering

Oroville dam is the tallest dam in the United States, but it has an auxiliary spillway that consists only of a 1,730 foot long spillway lip, that spills directly onto bare hillside.  Yuba County Water Agency (YCWA) raised concerns in 2002 about the damages that could occur from using the auxiliary spillway: The discharge area below the emergency … Continue reading YCWA concerns about Oroville’s auxiliary spillway