Dredging operation set to re-commence in New Year
Following a hold on operations earlier this month, dredging at the Whanganui Port is set to re-commence in January next year, as part of Te Pūwaha, the Whanganui Port revitalisation project.
A 40 tonne amphibious excavator, owned and operated by Murphy Civil Limited, is scheduled to create a clear channel from the Wharf Street boat ramp to the awa. This will improve access for the Whanganui Coastguard and recreational vessels, along with preparing for Q-West Boat Builders to move some of their operations on site next year.
Whanganui Port General Manager, Geoff Evans is looking forward to the arrival of the new kit to see what it can do first-hand.
“Murphy Civil is the dredging contractor for the Opotiki 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.”
“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 river bed, and float in deeper waters.”
“It has a traditional bucket mounted on the extended boom which removes material where the channel is required, and then deposits it either beside or behind the machine.”
“So rather than depositing the materials into the river channel, dredging will be by the side-casting method, which could be argued isn’t dredging but just moving material from one side to the other. However, it is the quickest method to opening up the navigable channels required for access by the Coastguard and other boat users.”
“The same method has been used by the Whanganui Port in previous years, but not as effectively or efficiently as what Murphy Civil will be able to achieve this time around.”
Once the dredge is on site, planned hours of operation are within the hours of 7am to 7pm each day, although the exact details are subject to current discussions and an application to Horizons Regional Council for a consent variation.
Whanganui Port will have a representative on site while the dredge is operating, to provide advice to boat operators on safe passage when moving from and to the ramp past the excavator. This person will also have direct communication with the excavator operator.
“While the dredge is in operation, we will continue to provide information and regular updates via the Whanganui Port and Te Puwaha social media channels,” says Geoff Evans.
It is also expected the Whanganui Port and Te Mata Pūau will maintain close contact and communication with Coastguard and the fishing club to resolve any issues that might occur during the operation.
“Boat operators and users of the boat ramp are asked to be patient, especially in the early days, as we get established and work out the best way to undertake the dredging operation with the movement of boats.”
In the meantime, Whanganui Port continues to work in the background on its long term dredging solution, in conjunction with Te Mata Pūau and interested parties.
To reduce the chance for river sediment being deposited back into the channels, planning and consultation is also underway to close the hole in the river wall adjacent to Q-West’s current premises in Gilberd Street. Whanganui Port are 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.
Once these requirements have been identified and agreed, it is likely that a resource consent application will be made early in the New Year so that closing off of the hole can be achieved sooner, reducing the risk of the planned dredging work being undone when the river is in flood.
Further information on the Whanganui Port dredging operation can be found here: Whanganui Port Dredging FAQs.
