Port Otago chief executive Kevin Winders said the new ''stringent requirements'' of the consent included the banning of discharges to air or water, and the company had no plans to spend ''millions of dollars'' covering the slipway.
It was unlikely the large tourism vessels which had frequented the slipway for sometimes major refits, or private fishing boats or any of Port Otago's fleet of tugs or dredges would be accommodated again, other than for mechanical jobs such as replacing drive shafts or other equipment.
''We consider this a 'sunset consent' as we're looking to relocate the slipway, given the [proposed] harbourside development,'' he said.
The former Otago Harbour Board installed the slipway and a boat cradle in 1978, upgraded it in 1984 to handle its suction dredge New Era, before ownership of the slip was transferred from the harbour board to Port Otago Ltd in 1989.
In September 2013 Port Otago built a new 17-tonne cradle at a cost of $80,000.
Mr Winders said he expected it to take about two years to decide on a location for a new slipway, potentially in the upper harbour or at Port Chalmers.
He also did not rule out Port Otago using the facilities at Lyttelton Port of Christchurch or South Port and sending its own vessels there for maintenance.
''It's the commercial realities of either major slip capital expenditure [here] versus using Lyttelton or South Port's existing services,'' he said.
Mr Winders said Port Otago was not planning any major upgrades or refurbishments to any of its own fleet of vessels at present.
During the next two years, Port Otago's focus was on the estimated up to $3million ''demolition and cleanup'' of its upper harbour Fryatt St wharf sheds, opposite the slipway, which had hundreds of degrading asbestos roofing sheets needing removal, he said.
