Australia’s Natural Population Growth Hits Historic Lows as Immigration Drives 80% of National Expansion
New demographic data reveals a widening gap between Australia’s "natural" internal growth and its overseas migration intake, with birth rates falling to record lows while net migration accounts for nearly 4 out of every 5 new residents.
Harry Taruva 
Canberra - Australia is undergoing a fundamental demographic transformation, as new data from the Australian Bureau of Statistics (ABS) confirms that the nation's internal natural growth has plummeted to its lowest level in decades.
While the total population expanded by over 423,000 in the year to September 2025, the vast majority of the increase m driven by overseas arrivals rather than local births.
The data reveals a scissors effect in Australian demographics; as the number of births minus deaths, natural population increase, continues to shrink, net overseas migration has surged to fill the void.
Over the last four years, approximately 1.58 million of the 2.02 million new residents added to the population, roughly 78.2 percent, were the result of migration.
Sustainable Population Australia (SPA) argues that this heavy reliance on migration to drive the economy is creating a lopsided society.
The group points out that natural increase has become a secondary factor in national planning, leaving the country’s growth almost entirely dependent on federal visa policy rather than domestic family expansion.
“The government is running an ‘ad-hoc’ immigration system at a time when our natural growth is already under pressure,” said Peter Strachan, National President of SPA.
“We are seeing a future where our food, water, and fuel security are being traded away for short-term migration numbers that the current housing market simply cannot sustain,” he said.
The disparity is particularly visible in the housing sector.
While natural population growth is predictable and allows for long-term urban planning, the sudden influx of 310,991 net migrants in a single year, more than triple the long-term average, has overwhelmed the construction industry.
Analysts note that while local growth usually involves infants who do not require immediate additional housing, every adult migrant arriving on a temporary or permanent visa requires immediate accommodation, further inflating the rental and property markets.
"Every person residing in Australia at any time needs food, water, housing and access to infrastructure," noted SPA spokesperson Michael Bayliss.
He argued that the current 1.5 per cent annual growth rate is physically impossible to match with new builds, leading to the current protracted housing crisis.
The shift also has significant environmental implications.
Advocates for a stable population argue that while a lower natural birth rate could eventually lead to a more sustainable environmental footprint, the replacement of that lower growth with high-volume immigration cancels out any ecological gains.
