The auditor-general has suggested such investment by port companies to take bigger ships could be working against the sector.
The annual report of the Office of the Auditor-general (OAG) into port companies was tabled in Parliament earlier this week and, while it did not make any recommendations, it observed competition was driving investment decisions which was not necessarily best for some smaller ports.
New Zealand’s 12 port companies were required by the Port Companies Act to operate as a successful business and the auditor-general acted as its independent auditor.
In the past five years, port companies invested about $2billion in their assets, mostly to accommodate the increasing size of visiting ships.
"This is a trend that has gone on for many years," the report said.
It noted the number of container ships carrying between 4000 and 6000 containers had increased to 62%, from 34% in 2014, while ships carrying smaller numbers of containers had significantly declined.
When contacted, Port Otago chief executive Kevin Winders said investment into accommodating larger ships was well worth it.
Port Otago was the last port of call in shipping giant Maersk’s existing Southern Star network.
"It needed the depth to get into port and to leave New Zealand in order to cater for the lower South Island exports.
"Without that depth we couldn’t cater for those ships so when we made that investment a number of years ago, it was a wise decision so our customers could have good access to markets overseas and the larger ships could get in to port," Mr Winders said.
The OAG’s report expected port companies investment into their assets to remain significant.
Mr Winders said most of Port Otago’s capital expenditure was complete.
"We have a very good consent to enable our harbour to be dredged to 15m if we have to.
"Our wharf infrastructure is in very good shape at Port Chalmers to accommodate larger ships so our capital expenditure is relatively complete in respect to that," he said.
The port was still battling with ongoing effects of the global shipping delay caused by Covid-19.
"There is plenty of disruption in the supply chain and the variability of the ships arriving and departing is quite wide.
"We have had a good flow of ships lately but we had a week of no ships, so we go from feast to famine.
"We’re hopeful it may settle down in the future but it may stay like this for a little longer," Mr Winders said.
