The iwi had not looked at the port as an area of involvement before but the reality was around building "a strong community relationship with an economic focus", Mr Mair said.
The first step will see about $1.5million being spent on upgrading the derelict and, in parts, dangerous infrastructure at Castlecliff. That money will come from the harbour endowment fund and work should be completed during the summer.
The first stage will focus on No1 wharf where the occasional coastal vessel berths. It will be upgraded to the equivalent of a class 1 highway standard, meaning it will be able to handle truck and trailer units.
There will also be work done in areas where cranes could operate in future. Some of the decking will be replaced and the sea wall under the wharf repaired.
No2 wharf would be restricted to handling light vehicles only while the third wharf, nearest the recreational boat slipway, would be looked at in the future.
Mayor Annette Main said focus was on No1 wharf and developing coastal trade, albeit in a small way. A business plan was being prepared and should be ready by the end of the year.
"Certainly there would be opportunities with existing businesses around here," said Ms Main.
"Things are happening here and it's how they could link in. We'd love to see the rail line re-instated and coming all the way to the port."
She said the joint venture was indicative of the confidence that was being felt in Wanganui and what could be happening at the port. "I'd like nothing more than seeing a mix of uses here ... "
Matt Doyle, chairman of Wanganui District Holdings, said earlier discussions with Port Taranaki had not made progress.
However, he said, the council-Tupoho deal did not lock it out.
"At the moment Port Taranaki's focus is on other matters, so we've decided to do our own thing and get on with it," Mr Doyle said.
Mr Mair said the deal represented council and Tupoho working together to benefit the community.
The council bought back control of the port and harbour endowment lease from private company River City Ports for $2.75million in September 2010, ending several years of legal wrangling over ownership.
Ms Main said Wanganui's port would never compete against New Zealand's major deep water ports but there was potential cargo in and out of the district that could be shipped through Castlecliff and these would be targeted by the port company.
Council will retain responsibility for recreational activities in the river basin and, jointly with Horizons Regional Council, for river management and the moles.