The Western Bay population is expected to swell to nearly 194,000 by 2026.
Figures from Stats NZ predict by the time New Zealand's population reaches five million in 2026, there will be 193,700 Western Bay residents.
The region's population stood at 162,100 last year, according to Stats NZ estimates.
Tauranga City Mayor Stuart Crosby said numbers in the Western Bay had increased steadily over the years, and higher numbers of young people and families moving into the region meant Tauranga was slowly beginning to shake its retirement-city status.
In the past five years, five schools had opened to cater for families, Mr Crosby said.
However, Tauranga's ageing population continued to be a significant factor in city planning.
"That's not bad - older people are a lot more active these days," Mr Crosby said.
"But at the end of the day, it's also one of the reasons why our council has a relatively high proportion of debt, because we are putting in infrastructure and services, not just for today but also for the future."
Tauranga City council debt was about $400 million, Mr Crosby said.
Tauranga MP Simon Bridges said a growing population meant the city would attract more resources.
"It means it's easier for small and medium-sized businesses to grow themselves because they get more customers. It means we can have better infrastructure and amenities in the city such as play grounds, sport facilities and museums. I'd be really happy if Tauranga continued to grow and grow."
Mr Bridges said he was looking forward to the results of the census to see how Tauranga's population had fared throughout the recession.
Western Bay of Plenty Mayor Ross Paterson said he was positive about the growth expected in his region.
"A lot of regional areas around the country are looking at a decline and we're looking at growth - that's a great thing."
Massey University sociologist Paul Spoonley predicted many of New Zealand's regional areas would struggle in the next 20 years.
"The challenge for regions is how do you keep jobs and how do you keep people?"
Professor Spoonley said more people were looking to New Zealand's largest city for better opportunities - a pattern set to continue.
According to Stats NZ, by the time New Zealand's population reaches five million in 2026, about 38 per cent (1.9 million) of the population will live in Auckland.
Currently, about one in three Kiwis call the City of Sails home.
He warned that "one industry" towns would face the biggest battle for survival in the next two decades.
Bay of Plenty town Kawerau, which has struggled with high unemployment, Projected population boom offers hope to region
Future Bright: There will be 193,700 Western Bay residents by 2026.Bay's melting pot, A15
job losses and teen suicides, was a prime example, he said.
Keeping the birth rate high was also important, he said.
Nationally, 61,178 babies were born last year, of which 2178 were to Western Bay mothers.
About 30,000 people died - 1284 were from the Western Bay.
But without job opportunities, younger people would be hard-pushed to find reasons to remain in many provincial areas.
And despite predicted increases in immigration numbers, which are expected to help overall population growth, Professor Spoonley warned that regional areas were unlikely to benefit.
"Our focus on migrants is on skilled people, so 60 per cent of our migrants come in the 'skilled and business' categories and they're really big town people."
One of the biggest challenges facing national population growth was competition from across the Tasman.
Stats NZ senior analyst Kim Dunstan said the mass exodus to Australia was one of the greatest contributors to last year's population growth of just 0.7 per cent - the lowest in 10 years.
And a New Zealand in Profile 2013 report, released earlier this week, predicted growth would continue to slow.