Building a new port at the Firth of Thames has received support in principle by the district's leaders.

A long-awaited report has suggested Manukau harbour as the best place to relocate Auckland's port, which will soon reach capacity.

It favours the Firth of Thames as a second choice.

Provided it meets environmental requirements, district mayors from Hauraki and Thames-Coromandel would be happy to see the port moved closer to home.

According to the report, a new port on the Firth of Thames has some perceived advantages in that its east coast location would be close to current shipping routes and close to landside supply chains around South Auckland and the Bay of Plenty.

There is sufficient natural depth and although the route has complexities, navigating large vessels into the Firth of Thames is likely to be straightforward, it says.

The port's C-shape design and breakwaters would provide protection from waves in a relatively unprotected environment, and while this would raise the construction cost, it is balanced by the lack of need for dredging.

Waikato regional economic development agency Te Waka says the port could provide significant economic opportunities.

'Subject to meeting environment and cultural requirements, a port located in the Firth of Thames offers significant economic opportunities for Waikato and builds on its natural advantages around transport and logistics hub locations,” chief executive Michael Bassett-Foss says.

Hauraki District Mayor Toby Adams agrees.

'Provided it meets all the environmental requirements I would be happy to see it closer to our region as it opens the door for employment opportunities and could also increase migration from Auckland to our communities,” he says.

Thames-Coromandel Mayor Sandra Goudie says the port would be a game changer for wherever it goes.

'If they think the conditions are going to be suitable for it, then bring it on.”

The focus of the report was on creating a new port in Kawakawa Bay, south of Waiheke Island, although other sites were not ruled out.

A new road connection would be needed, likely a four-lane road from the Mill Rd area with a bypass of Clevedon, with an improved connection from Mill Rd to the Southern Motorway.

A new rail line, connecting from the North Island Main Trunk, would traverse some complex topography near Kawakawa Bay that would require some high-cost tunnelling, the report says.

-Stuff