Vaughan Cooper, acting CEO of Northland Inc, said this scale of job creation would have positive ripple effects across the region's communities.
His claim was backed by Otago University Economics professor Dorian Owen, who said job creation in a region was always good for the wellbeing of residents, "because it creates income and then that gets spent locally and it sort of acts as a multiplier effect on the local economy".
Owen confirmed very few opportunities existed in New Zealand to create as many employment opportunities as were forecast with the expansion.
He said that was because the country being was dominated by small and medium-sized enterprises that tended to generate dozens or hundreds of employment opportunities rather than thousands.
And Northport's vision for growth wasn't an opportunity to be snubbed.
"I guess it's because employment is not evenly distributed in some areas and can end up with batches of unemployment which won't necessarily disappear," Owen said.
Northland's most recent annual unemployment rate was 3.6 per cent in the year to March 2022 - down 5 per cent from the previous 12 months but still higher than the national average of 3.4 per cent.
Jobs were not the only positive impact pegged in the report as the expansion was estimated to pump $160 million into the national GDP figures within the next 38 years, alongside $290m from the drydock and shipyard.
Cooper said Northport's growth would bolster the marine manufacturing sector, as well as infrastructure that would add to the region's "economic resilience for the future".
"The potential economic benefits of the expansion identified in the report are contingent on supporting infrastructure being completed, several of which rely on central government decisions," Cooper said.
"A rail spur to Northport and better roading connectivity to Auckland, as well as patient capital for the shipyard are outlined as influencing factors, as are the development of a marine skills cluster and full consultation around Te Tiriti o Waitangi conditions," he said.
Northport chief executive Jon Moore said they have openly shared how the port can play an integral role in the "resilient, geographically astute" supply chain strategy for the upper North Island.
"But only if decision-makers open their eyes to this potential and back our region with modern, 21st century transport infrastructure that Northland community and business leaders have been crying out for," Moore said.