OTTAWA 芒鈧珺次元官网网址� Colin Basran is having growing pains.

In some ways a victim of his own success, the mayor of Kelowna has been struggling in recent years to rein in his city as it slowly spreads across the B.C. interior, testing his ability to provide core municipal services and build badly needed infrastructure.

Nor is the city's middle-aged spread at all unique, according to the 2016 census data released Wednesday: Canada's population of 35.15 million is settling in the bigger cities, ensuring they and their suburban neighbours keep growing, while small cities get smaller.

The three biggest metropolitan areas in the country 芒鈧珺次元官网网址� Toronto, Montreal and Vancouver 芒鈧珺次元官网网址� are now home to more than one-third of all Canadians with a combined population of 12.5 million, with almost one half living in Toronto and its suburban neighbours, the data shows.

Canada is once again the fastest growing country in the G7, Statistics Canada says in the first of what will be seven tranches of 2016 census data to be released over the course of the year. Wednesday's release focused on population and dwellings; the next one, in May, will be focused on age and sex.

The latest figures also show that the once yawning gulf in growth rates between the spreading suburbs and their urban centres has continued to narrow, with young professionals and aging baby boomers alike opting for the downtown-condominium life.

The census shows that 82 per cent of Canadian population live in large and medium-sized cities across the country, one of the highest concentrations among G7 nations. Immigration has driven that change with new arrivals settling in urban centres as opposed to rural communities.

"The municipalities located on the edge of the (census metropolitan areas) are growing faster than the municipalities located (in the centre) of the census metropolitan area," said Laurent Martel, director of the demography division at Statistics Canada.

"Also the rural areas located outside the census metropolitan areas, but close to them, are also growing faster than rural areas much farther away, so that's also a sign of an urban spread phenomenon."

Canada's rural population is aging at a much faster rate than those in the urban centres, which tend to attract younger families, said Michael Haan, a sociology professor at Western University in London, Ont.

"Demographers call cities population sinks for a reason," Haan said. "Imagine you had all sorts of water on a counter and it all just runs into the sink and it never comes out again."

How to keep those sinks from overflowing has become an increasing concern for urban planners.

It's why suburban lots over the years have become smaller, circuitous streets designed for cars are being replaced with a transit-and-foot-friendly grid system, and dwellings are increasingly being designed to allow young families to age in place.

"If we have a whole bunch of really young population, now we know that they're going to start to age in our communities," said Eleanor Mohammed, president of the Canadian Institute of Planners, and chief planner in Beaumont, Alta., which grew at a rate of 31 per cent between 2011 and 2016.

"So, if you're community is really suburban, how do you create more density and a different built form that can help people age in place in the community they're in right now so that they don't feel they have to move somewhere else?"

In Kelowna, officials are encouraging people to live in areas that are already built out, as opposed to pushing the boundaries of the community further and further with new subdivisions.

The city's growth rate over the last five years was 8.4 per cent 芒鈧珺次元官网网址� the sixth highest among metropolitan areas in the nation 芒鈧珺次元官网网址� pushing its population to 194,882, the census found.

"What we're trying to do, as many communities are, is really trying to stop or limit sprawl and densify the areas that we already have because we know infrastructure is expensive," Basran said.

Not all cities and towns in Canada are looking to keep their borders from expanding. Many are simply trying to hold on.

Several small towns in Nova Scotia not attached to an urban centre, such as New Glasgow, Cumberland and Digby, watched their population figures drop in the census.

Saint John, N.B., was one of only two metropolitan regions across Canada that saw a drop between 2011 and 2016 芒鈧珺次元官网网址� from 70,065 to 67,575 芒鈧珺次元官网网址� mirroring a larger provincial trend. New Brunswick's population declined by 0.5 per cent, the only province to post negative growth since 2006.

Across the rest of Atlantic Canada, growth slowed largely because fewer immigrants came into the region and more people left the area to seek their fortunes elsewhere.

That elsewhere continued to be the West with Alberta growing at more than twice the national average, leading provincial growth for the third straight census cycle. Manitoba's population increased by 5.8 per cent, surpassing the national average for the first time in 80 years largely on the back of new immigrants.

Almost one-third of Canadians now live in the West, the region's largest share ever. Calgary and Edmonton were the fastest growing cities between 2011 and 2016, with Calgary leap-frogging Ottawa for fourth-largest overall behind the big three of Toronto, Montreal and Vancouver.

Quebec's population surpassed the eight million mark and Ontario's growth slowed to hit 13.4 million, still giving the two most populous provinces 61.5 per cent of the nation's population.

Nationally, growth slowed to about one per cent annually between 2011 and 2016, an extra 1.7 million people. That would have been even lower if not for an influx of new immigrants, which Statistics Canada says accounted for about two-thirds of the latest increase.

Statistics Canada projections suggest natural, fertility-fuelled growth will decline in the coming years, thanks to an aging population and a declining birth rate, to less than one per cent, making migration by far the dominant source of growth by 2056.

Those numbers and projections are why the federal government's economic growth council has recommended increasing immigration levels to 450,000 from 260,000 to ensure there are enough workers in the country to keep Canada's economy humming along.

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Jordan Press, The Canadian Press

Note to readers: This is a corrected story. An earlier version misspelled Colin Basran's last name.