During five to 10 percent of operations fish screen caught specimen from the end of the pipeline for monitoring and analysis.
At the end of August Vortex Marin Construction Inc. of Oakland California began maintenance dredging in the Sacramento and Stockton deepwater ship channels. The Corps of Engineers Sacramento District will likely ask for an extension past the dredge window to finish in December.
Vortex used the dredge Voracious on this $6.4 million contract which is an indefinite delivery indefinite quantity IDIQ contract. Vortex dredged in 2012 and will likely dredge during next year’s window.
The Stockton channel runs along the San Joaquin River and out to San Francisco Bay. The San Francisco District handles the first 40 miles of the channel. Then Sacramento District picks up the maintenance dredging from the city of Antioch to the port. The Sacramento District maintains the manmade upper portion of the Sacramento Ship Channel and the San Francisco District maintains the lower portion.
Sacramento District Project Manager Gary Kamei said the Sacramento channel will be dredged to 30 feet and the Stockton channel to 35 feet. The Corps won’t have exact numbers until after the dredging is complete in December but Kamei estimated that between 200000 and 300000 cubic yards will be dredged from Stockton channel and between 100000 and 200000 cubic yards in the Sacramento channel.
Vortex’s hydraulic cutterhead dredge will work in both channels. The Corps is responsible for dredging the channel and its non-federal sponsors the ports are responsible for providing the placement site for the ockton dredged material.
At the Port of Stockton sand from the channel will go to the Antioch Dunes National Wildlife Refuge where an endangered butterfly habitat needs sand to restore its dunes. Other placement sites for the duration of the dredging include sites parallel to the shipping channel that belong to the Port of Sacramento and along the Sacramento River near Rio Vista on the lower San Joaquin River at Sherman Island Scour Pond McCormick and the Port of Stockton’s site on Robert’s Island.
During the dredge window NOAA Fisheries requires the Corps to perform fish monitoring which has two parts – fishing the river for a population count and a fish screen at the end of the pipeline at the placement site used during five to ten percent of operations to capture fish specimen. Fisheries sends two biologists to identify the fish.
Kamei said he anticipates the district will get its extension. The Corps has a programmatic agreement with Fisheries regarding this maintenance dredging project which includes initial verbal communication that an extension may be requested.
“When we work with the agencies they like to see that we’ve made a good faith effort to complete the dredging on time” Kamei said. “If we didn’t start dredging until October then they’re less likely to grant an extension.”