A special suction hopper dredger will be stationed off Northport, at Marsden Pt, from today to dredge the seabed for the first time in 17 years.
Maintenance dredging is due to start at Northport today.
The work to remove sediment build-up in the ship turning basin near Snake Bank, along Northport's linear berth and at Refining NZ's Jetty 1 berth pocket, will continue for most of the month.
Northport said the work has nothing to do with either its vision for growth, unveiled earlier this year, or Refining NZ's channel deepening programme.
"The operation will be highly visible so we wanted to head off at the pass any concerns that it has anything to do with either of those projects," said Northport chief executive Jon Moore.