A High Court decision has cleared the way for dredging work to start on Tauranga Harbour, giving access to larger ships and expanding trade by tens of millions of dollars a year.
The Port of Tauranga says the $80 million project to deepen and widen the harbour should start late in 2013 after the court dismissed an appeal against the plan.
In 2011, the Environment Court upheld a decision made by a panel of commissioners to grant the port consent to dredge the harbour to a maximum depth of 17.4 metres.
Local iwi and hapu - including Ngati Ruahine - lodged an appeal in the High Court against the Environment Court decision, but that was dismissed on Tuesday.
Port of Tauranga chief executive Mark Cairns says the High Court decision is crucial to the industry.
"The Shippers' Council and a lot of New Zealand exporters are calling for a design class vessel which requires 14.5 metres draft - a very large vessel up to 1000 containers.
"We think that's some way off, so we've agreed in the Environment Court that we will do the dredging in stages. Part of that work we need to do over the next year is to determine with our customers what's the most likely class of vessel in the next five years.
"We think that will be a 4500 to 5500 container vessel and will require us to dredge to handle vessels of around 13.2 metres depth. If we do that, that could be a six-month construction project once we start the work."
Mr Cairns says the decision still has to be approved by the Conservation Minister and the company will spend the next year consulting with iwi and clients on the dredging plans.
The first stage will give access to ships carrying 5000 containers and further work will allow vessels with up to 8000 containers.