Auckland's population is about 1.7m, home to just over one-third of the country's population (34 percent) and by 2048, it could make up 37 percent.
"Auckland will likely have the highest average annual growth of New Zealand's 16 regions over the next 30 years, from net migration and natural increase (more births than deaths) in relatively equal shares," population estimates and projections manager Hamish Slack said in a statement.
