Manuherekia Valleys Charitable Trust chairman Andrew Paterson said the first emails about the project were exchanged with Paula Penno at the Central Otago District Council in 2016.
Breen Construction will start excavation work on the site today.
Site preparations had already started, including removing trees to make way for the new building.
The new hub was a collaborative effort between the council and the community, led by the trust.
Mr Paterson said he was delighted to see work beginning.
"We’re over the moon to think that we’ll soon be turning the turf on a project that has been so long awaited and needed by the community."
The project had taken off over the past three or four years and the committee tasked with the project had worked really hard to get to this stage, he said.
After a feasibility study funded by the Central Lakes Trust, initial funding came from a crop challenge run by Poolburn and Omakau Schools and the Central Otago Collie Club, which raised about $35,000.
Other funders ranged from the council to the Central Lakes Trust and Central Otago businesses.
"Council support has been awesome," Mr Paterson said.
"The Vincent Community Board has backed us the whole way too. With the council funding $1million of it, that’s a pretty good start."
There was even a donation from the Wakatipu Rugby Club, which was a real surprise.
"They rang up and said, look, we love coming to Omakau to the rugby club. We’d love to help you."
With $3.5m already raised towards the expected total build cost of up to $4.1m, the project was approved to proceed in July, after the council promised to fund the remaining shortfall on top of the $1m already approved from Vincent ward reserves.
"It’s been a real collaboration. And we’ve tried to find ways of keeping the costs down.
"And when we went out to the building community ... we essentially aimed it at local builders.
"And the three local builders that put in tenders, put in amazing tenders. You know, even the highest one still would have been a good tender for us to get. We had expected ... it was going to be a bit higher," Mr Paterson said.
"And so, we know that those building companies priced it with the community in mind."
With a good deal on the price, the building would be completed in one stage to "turnkey" — immediate use — which was more than the committee had anticipated.
The committee was still fundraising for the internal fitout and landscaping.
The next part of the project would include a new campground kitchen and removal of the rugby clubrooms.
It was estimated the build would take a year, but it might be faster than that, depending on the weather during winter, Mr Paterson said.
For construction company Breen, it was a "back to the future" moment.
Managing director commercial Peter Breen said the company and the domain went a long way back.
"The Breen Construction team is thrilled to be back at the Omakau Domain constructing this community hub 70 years after completing the original pavilion."
Mr Paterson said there would be a golf tournament at Omakau on December 28 to raise more money, and planning was under way for a big fundraising event in the new year.
