A scenic section of the Bow River pathway in southeast Calgary will reopen soon after three years of work and 236 massive concrete piles to shore up the slumping hillside — but the city won't yet say what the project has cost.

It has taken three years to reshape the hillside high above the Bow River along the communities of Douglasdale and McKenzie Lake, with crews drilling 236 holes down into bedrock, each one metre wide and 30 metres deep. Enormous tubes made of steel rods were inserted into the holes, which were then filled with concrete. A 300-metre-long retaining wall was built featuring a new paved pathway on top.

That section of the pathway, closed since 2016, is set to reopen next month. As many as 2,000 people a day used the pathway before it was closed.

It's a massive project with a multimillion-dollar price tag — although just how much it cost isn't being made public, for now.

Jason Lin, a structural engineer for the city who's manager of the project, says the budget is part of a confidential report that went to members of Calgary's city council and is being kept under wraps.

So did the project come in under budget? Over budget?

"That's all part of the budget that is confidential," said Lin.

The Douglasdale-McKenzie Lake slope before restoration work started in 2016 to stabilize the escarpment on the east side of the Bow River. (Google)

The Douglasdale-McKenzie Lake slope stabilization project is listed on a Government of Alberta webpage that highlights major projects.

The estimated cost is pegged at $13.3 million, which the city would not confirm.

It's been reported the cost could run as high as $25 million.

Peter Demong, the city councillor for the area, says the project cost can't be revealed until all of the work is done. He says that could happen sometime next year.

37 Calgary Towers

The scale of the stabilization project is hard to grasp since most of the work can't be seen.

The 236 piles would stretch as high as 37 Calgary Towers if the piles were stacked up on top of each other. That's just over 7,000 metres.

One of the 30-metre-long tubes inserted into 236 holes along an escarpment in the southeast community of McKenzie Lake. (City of Calgary)

Some of the piles have been anchored into bedrock with the tie-ins cut diagonally, deep underneath private property lines.

The retaining wall along Mount Alberta View S.E. is about 300 metres long and about three metres high.

The city has been exploring different options to fix the problem since 2005. Heavy rainfall over the years has caused slope movements along the escarpment, damaging a 3.5-kilometre section of the Bow River pathway.

Steven Graupe, who lives on Mt. Douglas Close S.E., looks out over a section of the Bow River pathway, which is set to reopen next month. It's been closed for three years while the hillside was stabilized as part of a multimillion dollar project. (Bryan Labby/CBC)

"It's finally coming to an end," said Steven Graupe, whose house backs onto the ridge in McKenzie Lake.

Graupe's house isn't as close to the edge of the hillside as some of his neighbours' homes, but he's relieved the city finally committed to finish project.

"The people that were most affected, at least they can sleep at night knowing that they're not going to fall off the edge of the cliff into the river," said Graupe.

"It's been noisy, it's been smelly, it's been dusty, It's been very difficult selling real estate along the ridge while all this is being done," he said.

Graupe's house has been on the market for a few months and he's hoping to get a few offers now that the project just beyond his backyard is winding down.

Several houses on the ridge are listed for sale, ranging anywhere from $1 million to 1.4 million.

He says he would like to know how much money was spent on the project, not just for him but for all Calgarians.

"It has to be in the tens of millions, but I really have no idea," he said.

"Three years of work, sometimes crews 30-40 people here, lots of heavy equipment, just the drilling and cement trucks — there was a parade of cement trucks," Graupe said.

Crews are now focusing their attention on stabilizing the hillside below Douglasdale Point S.E. The city expects that section of new pathway to reopen next spring. (Bryan Labby/CBC)

Construction continues farther north

Crews working on the slope stabilization project are now focusing their attention on the hillside just north of 130th Avenue S.E., west of Douglasdale Point S.E.

The hillside is being flattened. Piles will be driven at least 15 metres into the slope and the pathway will be rebuilt. Lin says it should reopen next spring.

"I definitely appreciate the homeowners' patience throughout this whole process," he said.

Bryan Labby is an enterprise reporter with CBC Calgary. If you have a good story idea or tip, you can reach him at bryan.labby@cbc.ca or on Twitter at @CBCBryan.