Overview
The Oroville Dam is a 770-foot earthen embankment dam on the Feather River, impounding Lake Oroville. Heavy rainfall during the California floods damaged both the main and emergency spillways, prompting the evacuation of more than 180,000 people and the relocation of a fish hatchery.

Scope of Work
Ballard responded to the emergency call from the Department of Water Resources (DWR) to mobilize the barge, equipment, and personnel to the Oroville Dam Spillway. The call was received on February 10, 2017, at 19:58, and Ballard began immediately mobilizing equipment and personnel to the site at 20:14, that same evening. Due to our expertise in mobilizing personnel and equipment to our national and international clients on a 24/7 basis, Ballard was able to quickly respond on February 11, 2017, at 02:34 with a modular barge, two cranes, and a team of personnel who began assembling the equipment.

Innovative Solutions
As the emergency at the Oroville Dam Spillway increased over the next couple of days, Ballard was tasked with providing additional equipment. This included five modular barges, hydraulic dredge pumps, dewatering pumps, and a crane for clamshell dredging. The Ballard team worked 24/7 to assemble all the equipment, and Ballard was staged at the bottom of the spillway when the DWR turned off all flows.

Results
Ballard exceeded DWR’s schedule and began excavating with one clamshell barge, two excavator barges, and three material barges on the upstream side of the spillway. Outfitted with complete dredging equipment, survey equipment, and real-time dredging software, personnel continued to remove material from the spillway on a 24/7 basis. Ballard’s primary goal was to dredge material from the river’s left side of the spillway to allow the upstream water to recede and prevent flooding of the powerhouse. During the project, Ballard removed approximately 20,000 yards of material, opening the original channel on the river left, preventing the powerhouse from flooding. Dredged material was transported to the shore and offloaded from the material barges, using a land-based clamshell crane. Once the powerhouse was no longer in jeopardy of flooding, Ballard demobilized from the site.