Tauranga city's population could rise to 168,400 by the year 2031, according to figures released by Statistics New Zealand.
The medium number of people living in Tauranga last year was estimated at around 115,800.
This was expected to hit 121,700 in 2016, 131,800 in 2021, 142,000 in 2026 and 151,900 in 2031. The highest forecast figure for Tauranga in 2031 was 168,400. The lowest projection for 2031 was 136,000. Tauranga Mayor Stuart Crosby said the city was, for now, in a "sweet spot" in terms of growth.
"That's where we want to be. Excessive growth creates problems and no growth can mean you are going backwards," he said.
"My goal is to create a city for all ages and create an environment for everybody to want to live here, feel safe here and enjoy life here."
Mr Crosby said there were "weaknesses" that were being addressed, such as the SH2 traffic congestion between Katikati and Te Puna, and congestion at 15th Ave and Turret Rd.
"I think the key issue for me with population growth is growing our economy. That means good productive jobs, so a lot of our planning is about securing and creating an environment to attract and retain productive jobs."
A Statistics New Zealand spokeswoman said a summary of regional population projections in 2010 suggested Tauranga would experience a faster population growth but the latest figures, although an increase had been projected, were less dramatic.
Overall, the Bay of Plenty population was forecast to rise by 6 per cent, (317,400) by 2031.
The region, along with Canterbury, was predicted to have the second highest average growth rates in New Zealand over the 25-year period.
No other main centre was expected to grow as much as Auckland, which was forecast to reach 1,968,100 people - a growth of 38 per cent.
The figures were collated by using information from New Zealand's 16 regional council areas and 67 territorial authority areas based on boundaries at January 1, 2013.
The information supersedes the equivalent projections released in 2010, which were based on boundaries at June 30, 2009.
Photo: A view looking over the Tauranga Harbour and suburbs Otumoetai and Matua - Mark McKeown.