VANCOUVER -- 'Tis the season for water main breaks in Metro Vancouver.

Two more pipes burst in the region Friday, bringing the total to five such incidents over the last four days. The reason? Many of Metro Vancouver's water pipes are aging and are vulnerable to bursting in cold weather.

Cold weather makes the pipes contract, said Daniel Roberge, director of water and sewer infrastructure at the City of Vancouver.

The older the pipes are, the more vulnerable they are to failing, Roberge said. This is true whether they're made of steel or cast iron, which is the case for some of the region's oldest pipes.

The result, as many residents found this week, can be a mess.

Crews closed traffic lanes on Nanaimo Street in East Vancouver Friday morning after a water main break near the intersection with Pandora Street.

Later in the day, the District of North Vancouver tweeted that there had been a "significant" water main break in a residential neighbourhood at the intersection of Hoskins and Draycott roads.

The district turned off water to roughly 20 homes as crews worked to repair the break. Water was expected to be restored by 11 p.m., the district said.

On Tuesday, a ruptured pipe in Surrey flooded several homes and turned streets near the intersection of 132 Street and 95A Avenue into rivers.

The following day, it was Vancouver's turn. A water main break near the Vancouver Art Gallery at West Georgia and Hornby streets delayed traffic for several hours.

Burnaby residents had their homes flooded early Thursday morning when a water main broke near the intersection of Gilmore Avenue and Dominion Street.

Friday's incident is the least severe of the bunch, with photos from the scene showing only a small amount of flooding.

The City of Vancouver tweeted that crews were en route shortly before noon to repair the ruptured pipe. Northbound traffic on Nanaimo Street was reduced to one lane while they worked. 

Roberge said the burst pipes underline the importance of replacing the region's aging pipes. When it comes to the City of Vancouver, the city was until recently only replacing pipes at a 0.5 per cent renewal rate – well below the industry standard of 1.2 per cent. The lifespan of a pipe is around 100 years, and the steel pipe that burst at Hornby and Georgia was around that age – and had rusted right through.

"If you do the math, if the pipe is supposed to last 100 years, we should do at least 1 per cent a year to stay ahead of it," Roberge said.

That's why the engineering department has been making the case to Vancouver city council to up the amount the city spends on pipe replacement. Last year, council approved a four-year plan to increase the pipe replacement rate to 0.7 per cent. In 2019, the city budgeted around $18 million to replace pipes.

If residents notice a flooded street, Roberge said they should report the incident to their municipality (in Vancouver, call 311).

"We send people right away to see if we can throttle some of the water and be of assistance," Roberge said. "Then we come in and assess what's happened and try to do repairs as quickly as possible."