The US Army Corps of Engineers (USACE) and Cottrell Contracting have begun dredging the Norfolk Harbor inner channel and channel to Newport News in the US State of Virginia.
The USACE's Norfolk District will manage the operations and maintenance project as part of an effort to remove shoaling, allowing safe and unrestricted navigation for large commercial and military vessels transiting into and out of the Port of Virginia.
Officials expect it to take five months to complete the work.
The US$10.4 million contract, awarded in August 2019 to the Chesapeake-based company, permits the dredging of approximately 840,000 cubic metres of sediment from the federal channel. Cottrell will pump it by pipeline to the Craney Island Dredged Material Management Area in Portsmouth.
Cottrell is dredging to a depth of 15.8 metres below mean lower low water, a formula based on the lowest tide's average height measured over a 19-year period.
This dredging depth ensures that as the channel shoals in between maintenance cycles, the shoals will still be below 15.2 metres, the depth required to keep commerce flowing in the Port of Virginia.
Maintenance dredging is required every 12 to 15 months in Norfolk Harbor Channel and every three to four years in the channel to Newport News. Without it, the high rate of shoaling would severely restrict vessel movement within the port.