The $US37 billion Inpex natural gas project is now in its final construction phase.

The giant site near Darwin is scheduled to start processing LNG by next year, and with very little building work left, there will soon be far fewer workers at the site.

The last three modules — enormous pieces of machinery and processing equipment — have arrived at the Inpex-led Ichthys project in Darwin Harbour.

The delivery is the last of 230 modules, signifying the end of the module delivery and final construction stages, ahead of testing, commissioning, and start-up phases.

Ichthys will take natural gas from off the coast of WA and pipe it 900km to a processing plant in Darwin Harbour.

There are currently just over 8,000 people working at the site every day, with another 4,000 local contracts as well.

When Inpex starts on its ramp down procedures after construction completes, it will whittle down to a continuous operations staff of about 400 people.

The company says the plant will be shut down for maintenance each year, which will involve some local contractors.

Greg Bicknell from the Northern Territory Chamber of Commerce has told reporters that the loss of jobs was expected, but will hurt.

“We won't see the same number of people visiting through the airports … there'll be some impacts on accommodation, the general retail spend,” he said.

“It's a fair impact over the period that they've been doing the construction and at a very welcome time.”

Mr Bicknell said construction projects including defence infrastructure, a new five-star hotel, and parts of the Darwin Port will help fill the void left by the completion of Ichthys.

“We've got the defence infrastructure build-up that's been talked about so that is a major spend over the next long term so that's very important in terms of the construction sector,” he said.

“Further out of Darwin, we have the Tennant-Creek-to-Mount-Isa gas pipeline.”