Tauranga Mayor Stuart Crosby said population projections were important when it came to planning ahead.
"We know we are continuing to grow and our over 65s are continuing to grow as well."
Mr Crosby said since the census, the city's population had already increased to more than 120,000 people.
To cope with the increasing and ageing population, Mr Crosby said Tauranga City Council had two key roles - to make sure there was adequately zoned and serviced land available for new residential development, and for new business development.
The statistics predict the city will attract more young people, with an extra 13,400 15 to 39 year olds expected to make Tauranga their home.
Mr Crosby said most of the city's growth would come from migration, not births.
"That's new people coming into the city from around New Zealand as well as from all over the world.
"It varies from year to year where they come from. The real estate agents tell us they're seeing a lot of people coming here from Auckland."
Mr Crosby conducted citizenship ceremonies as part of his civic duties.
Newcomers were from the UK, South Africa and Asia.
"We're also getting some from South America - Brazil and Chile.
"Tauranga has become quite multicultural."
GreyPower coastal Bay of Plenty and districts president Ruth Dekker said the city council was trying to put infrastructure in place for the ageing population.
"We have attended various meeting that have been council-backed about what sort of things would be necessary in our view to make it a more age-friendly place to live."
Mrs Dekker said some aged people could not use some services intended to be elderly-friendly, such as the bus service.
The service was no use to someone who was not mobile enough to walk the two roads to the nearest bus stop. Mobility was a big issue, Mrs Dekker said.
Colin has seen huge growth in the Bay since the 60s
Colin McLean moved to Tauranga in 1962 after doing a stint for radio in Hamilton for a short time.
He worked for 1ZB for four years before moving on to National Radio in Wellington.
"I retired in 1990, then came back here in 1992, I've got a daughter, her young family here and most of our friends were in Waikato, Bay of Plenty and Auckland at the time," he said.
Mr Mclean said Tauranga was beautiful and he too had noted the growth in the city over the years.
"When I lived here in 62 to 68, Tauranga was a borough, I think it was about 64 they got city status and bought Greerton county.
"The growth since I have been back here since 92 has been absolutely incredible."
Mr McLean said he loved living in the Bay because of the accessibility to the outdoors.
"I play indoor and outdoor bowls, I like trout fishing and go over to Rotorua and I've got a camper which I go away in," he said.