With construction season around the corner, Grande Prairie is gearing up for the third phase of a multi-year project to replace downtown storm and sewer pipes.

The city launched its redevelopment of downtown infrastructure in 2013. The first phase of construction started in 2016, with a second phase ending in 2017.

"For many years, our downtown core maybe hadn't received the attention it needed," Mayor Bill Given told CBC News.

"This kind of infrastructure is absolutely not sexy, but it's completely necessary. These are the types of things that, until a problem happens, people don't think about. And that's why I think it didn't receive the attention it deserved for many years."

This kind of infrastructure is absolutely not sexy, but it's completely necessary. - Bill Given, Mayor of Grande Prairie

Severe weather in recent years has emphasized the need for updated infrastructure to handle storms and flash floods, Given said.

"During those kind of rain events, it became very obvious that the infrastructure was inadequate for both the growth that we've seen in our community and the severity of storm events that we're seeing today," Given said.

"Some of this infrastructure would have been in place at the time when Grande Prairie attained village status. Much of it hadn't seen attention since that time, so it's not a surprise to me at all that it was time to do something."

A summer rainstorm submerged areas of downtown Grande Prairie in August 2016, prompting an emergency alert from the city as water seeped into homes and businesses.

"It was the heaviest rain I had ever seen," recalled Matthew Olsen, manager of the Wonderland Toy store in Grande Prairie's central business district.

The store's basement flooded within minutes, after a toilet backed up, he said.

"There was a bubbling, crazy amount of water coming out of there," Olsen said. "Puddles turned into a good six inches everywhere."

Water wiped out about 80 per cent of the store's inventory, which was kept in the basement. Olsen estimates the damaged stock was worth at least $150,000.

Wonderland Toy was forced to shut down for eight months during repairs. More than once, the 26-year-old business teetered on the brink of closing for good, Olsen said.

The store reopened in May 2017. Olsen hopes the city will complete its redevelopment project before another storm can sink the business.

"It's extremely important," he said. "It's important because the downtown shops are what bring people here, and this really is the centre of Grande Prairie."

Pipes from the 1930s and '40s

Grande Prairie's downtown infrastructure is the oldest in the city, said Jeff Johnston, chief operating officer for Aquatera Utilities.

The company, which is responsible for maintaining the city's sewer system, is co-owned by the City of Grande Prairie, the County of Grande Prairie and the nearby town of Sexsmith.

Though some of Grande Prairie's downtown pipes are more than 75 years old, Johnston said an assessment completed by Aquatera in 2014 showed they could last another 30 years.

"If the city had not had this initiative, we wouldn't have gone in and replaced these pipes," Johnston said. "We haven't had a large amount of maintenance problems with it, so it's really not on our immediate radar to do any replacement."

The downtown sewer pipes are made of clay tile, while the water pipes are a mixture of asbestos and cement, something Johnston said is normal for older infrastructure.

Aquatera is replacing the aging material with PVC pipes, which have an expected 100-year lifespan.

Where possible, the company will also separate storm systems from sanitary systems to reduce the risk of storm water backing up the sewers, Johnston said.

"It should reduce the impact of any storm event," he said.

"If it's viable, we'll do it," he said. "But there's a limit to what we can do, especially in a retrofit and redevelopment kind of situation.

"Ideally, the storm system and the sanitary system are independent of each other, and that's not always necessarily the case in older areas."

A third phase of construction will begin in 2018. Redevelopment will also include updates to streets and sidewalks, the mayor said.

"The intention of council is to create opportunities for us to grow upward by attracting some new density into the downtown core," Given said.

"Ensuring that we have a vibrant, urban centre that is truly reflective of a city of 100,000 people, which we will be, soon."

The city has allocated $20 million for the downtown rehabilitation project.

@ZoeHTodd