In January 2015, HDR was awarded a master dam safety services contract by the California Department of Water Resources (DWR), Dam Safety Branch, to provide engineering services throughout the State Water Project.

On February 7, 2017, during routine visual inspections, DWR discovered damage to Oroville’s main spillway. At 770 feet high, Oroville Dam is the tallest dam in the United States, serving primarily as a water supply (1 trillion gallons of water), a source of hydroelectricity, and for flood control.

In just over three days, HDR mobilized 50 staff from across the U.S. to conduct services around the clock, 7 days a week supporting DWR’s mission at the dam. Our role focused on monitoring and reporting various elements of the Oroville Dam Spillway Incident Response project, serving as an extension of DWR’s Operations and Maintenance Division. We reported up through the Dam Safety Services Office and the Incident Command structure.

The primary objective of our monitoring activities at the flood control outlet was to provide data and information regarding the condition of the spillway structures and erosion areas as input for emergency response decision-making by DWR. Not only were we tasked with monitoring the Oroville Dam, but also the Oroville-Thermalito Complex (a group of facilities and structures around the City of Oroville), including the Thermalito Diversion Dam to observe and report possible large debris, such as logs, that could affect gate operations and dam safety.

During the monitoring effort, we led staffing, scheduling, resourcing, and safety for 150 staff, including 26 rotating positions (52 staff per day). Our support to DWR’s Dam Safety Service Office included around-the-clock coverage for several months for all monitoring positions, including Chief Monitoring Engineer, Monitoring Lead, Monitor, Roving Monitor, Safety Lead and Coordinator, Communications, Data Analysis and Reporting. Our staff included engineers, inspectors, construction experts and safety advisors who covered all aspects of geology, geotechnical, structural, civil and scour elements.