Dredging to restart at Whanganui Port in January

The 40-tonne excavator will begin work in January. Photo / Supplied

Dredging will resume at Whanganui Port in the form of a 40-tonne amphibious excavator.

An incident this month involving a barge forced a temporary pause to dredge operations, with port general manager Geoff Evans saying its load had become unbalanced.

The vessel “tilted on its port side until it sat on the bottom of the river – about 35 degrees to the vertical".

Until now, dredging has been undertaken using a digger on a barge.

In a statement, the port said the excavator, owned and operated by Murphy Civil Ltd, would create a clear channel from the Wharf St boat ramp to the Whanganui River, improving access for the Coastguard and recreational vessels.

Evans said he was looking forward to the arrival of the new kit “to see what it can do first hand”.

It will begin work in January, with operating hours expected to be between 7am and 7pm each day.

“Murphy Civil is the dredging contractor for the Ōpōtiki Harbour Development project, where they are creating a new harbour entrance and closing off the old river channel, so they have considerable experience in river dredging,” he said.

“The amphibious dredge is much bigger than our current dredging operation and we are expecting that it will move the silt more efficiently.

“In basic terms, it is a track excavator with large pontoons on either side which allows it to track on both sand and the riverbed, and float in deeper waters.”

The excavator had a traditional bucket mounted on an extended boom to remove material where the channel was required and deposit it beside or behind the machine, he said.

“This is the quickest method to opening up the navigable channels required for access by the Coastguard and other boat users.”

Evans said the channel would also allow Q-West Boat Builders to move some of its operations to the port site next year.

In October, port chairman Mark Petersen said the plan was to have Q-West’s electric-hybrid ferry – a 34.5m vessel being built for Auckland Transport – on the port’s hardstand in the first quarter of 2025.

Once finished, the navigable channels were expected to remain open for the summer season, subject to extreme weather events, Evans said.

“To reduce the chance for river sediment being deposited back into the channels, planning and consultation are under way to close the hole in the river wall adjacent to Q-West’s current premises in Gilberd St.

“Whanganui Port is also relooking at reclamation in this area as a location for dredged material to be deposited, rather than into the main river channel which risks causing issues at the river mouth or bar with a build-up of material.”