Work to accommodate the arrival of four new P-8A Poseidon aircraft will soon start at Manawatū air force base Ōhakea.

The Government has bought four new P-8 Poseidons, which cost $2.3 billion and will be in action by 2023, to be based at Ōhakea. The planes, which haven't been built yet, will replace the air force's aging P-3 Orions.

Ōhakea is in line for infrastructure upgrades expected to cost about $300 million, including a new hangar, extra accommodation and mess facilities, to accommodate the Poseidon maritime patrol aircraft, which should arrive in 2022.

Ōhakea will be home to four P-8A Poseidon aircraft from 2022.

Ōhakea base commander Shaun Sexton said work would soon start on a new hangar, which would run in an east-west direction, with one end near State Highway 1.

"They will put in water and electricity and all that important stuff, as well as roading and new tarmac space for the aircraft," he said.

"That work is going to start in October and then from there it will slowly progress to building the new hangar and training, maintenance and operational facilities.

"By some time in 2022, I don't think we have a hard date yet, but that will be all finished and up and ready for the aircraft to arrive."

Ōhakea base commander Shaun Sexton is looking forward to the arrival of the new aircraft.

He said it was a large and complex build and work needed to start early. Tender documents were out now, he said.

Sexton said the arrival of the Poseidons and No 5 Squadron, who will operate the planes, from Whenuapai in Auckland would have a big influence on the region.

"We've got some experience moving large volumes of people down to Ōhakea. We did it about 15 years ago with No 3 squadron and we'll leverage that experience.

"We're already starting to talk to the local communities, the mayors and the councils about the challenges and opportunities that it presents and we're starting to talk to our people a little bit about that as well.

"Of course, it's two to three years away so you don't want to start too soon, but certainly there's an awareness growing of the need to start progressing things for 2023."

Defence Minister Ron Mark said the arrival of the planes and shifting the new squadron to Ōhakea would be good for the local economy.

"It's good for Manawatū. There will be a hell of a lot of contractors and builders who are going to get the opportunity... Manawatū is going to see more families moving in, kids going to their schools and district health boards seeing more people."