The Government is to spend up to $29 million on improvements to the Opotiki River in a bid to unlock aquaculture investment in the Eastern Bay of Plenty.

After years of lobbying, Economic Development Minister Steven Joyce and Associate Economic Development Minister Te Ururoa Flavell travelled to Opotiki to announce $3m for a final design and geotechnical study.

The Government has said it will contribute up to $29 million on a project to develop the Opotiki River, which aims to unlock aquaculture investment in the region. Photo: Stacy Squires.

If the study proves the project is feasible, the Government has indicated it would consider up to another $26m for river mouth work to improve its navigability, as well as the building of a commercial harbour. All up the project would require investment of more than $200m.

The Bay of Plenty Regional Council has already committed $20m towards the project.

Problems with the river mouth are believed to be holding up substantial investment in the region, including plans for a 3800 hectare mussel farm to the east of Opotiki. However locals have said they cannot possibly fund the project without outside help.

Opotiki has been calling for Wellington to help fund the project for years, and had already had indications of high level support from both Labour and National.

In 2013 then Opposition leader David Cunliffe named the river development among a group of regional projects he wanted a Labour-led government to consider supporting.

Then in July 2014 John Key revealed that the National-led Government was already looking at contributing funding the project.

Just moments after dismissing Labour's plans for a regional development fund as a "slush fund", John confirmed that National was looking at special support for Opotiki.

"From time to time on an ad hoc basis the Government does get involved and we can see logic about what they're talking about there," says John.

On Thursday a deal was announced to fund a final study on the river project.

"The Opotiki Harbour Development Project is an exciting, community-led strategy to revitalise the economy of the eastern Bay of Plenty through the development of aquaculture, related industries and most importantly, jobs," Joyce said in a statement.

The Government claims the project has the potential to create 220 jobs in the region and boost economic output by up to $55m a year. Te Ururoa says the study would look at options to make the river navigable year-round.

"The engineering assessment will be completed within the next two years in parallel with industry testing of the commercial viability of the mussel farm.”