West Coast Hopper, CA
The West Coast Hopper contract consists of three individual dredge projects: San Francisco Entrance Channel, Humboldt Bay Entrance Channel and the entrance to the Columbia River from Astoria to Longview. eTrac has been contracted as a third party surveyor for the USACE and conducts conditional surveys throughout the project duration in various locations. Surveys provide the dredgers with updated material surface conditions to optimize their operations and to assist in efficiently dredging to project grade. eTrac utilizes survey vessels outfitted with R2Sonic multibeam sonar equipment and Applanix POSMV position and motion systems. Dredge locations in San Francisco and Humboldt utilize RTK base stations to broadcast corrections to the vessel as opposed to operations on the Columbia River where tide monitoring stations are implemented for vertical accuracy to correlate CRD (Columbia River Datum). Survey episodes are coordinated around weather conditions as well as sea state as most areas are located in challenging open water environments. The Columbia River Bar and Humboldt Bar are considered two of the most dangerous bars on the west coast. In addition the dredge survey site, eTrac was also tasked with surveying offshore disposal zones for these projects to monitor material placement.