A third of Toronto's hydro infrastructure is past its best-before date.

Toronto Hydro says billions of dollars worth of power lines, heavy-duty fuses, and transformers need to be refurbished or replaced.

Officials say unless the necessary improvements are made, blackouts like the one that left hundreds in East York in darkness over the weekend will become more common.

The city's power problem is a perfect storm, of sorts.

Toronto Hydro spokesman Blair Peberdy says its partly due to the sheer amount of infrastructure that was built in the 1960's and 70's.

"Because most of this infrastructure was put in many decades ago, it all seems to be coming to the end of its life at about the same time," he says.

Peberdy points out that the issue is not unique to Toronto's power grid.

He says evidence of a lagging maintenance be seen in the city's bumpy, pockmarked roads, decaying subway stations and the chunks falling off the Gardiner Expressway.

"I think it is a symptom of underspending from decades before that has now come home to roost," Peberdy says.

Adding municipalities across North America are having the same challenges, he says governments perform a difficult balancing act of investing in proper up-keep on infrastructure while managing what taxpayers can afford.

Peberdy says 'several billion dollars' are needed over the next few years to get caught up on the required improvements.

In the meantime, he expects power outages will become more common in Toronto until the system gets out from behind the 8-ball.

"This is a problem we've seen increase over the past 5 or 6 years ... the longer we put [replacing infrastructure] off, I think the worse the problem is going to be and the more expensive it will be to fix it," Peberdy says.

To raise money for repairs, Toronto Hydro has asked the Ontario Energy Board for $1.4 billion over the next 3 years, which means a possible $2 per month hike the average hydro bill.

That could come as soon as May.

However, Peberdy expects there are more increases to come.