Early works on the $23.5-million Bentway public space project under the Gardiner Expressway in Toronto are well underway with project managers predicting Torontonians will be gliding along a new skating trail and taking in cultural events at new outdoor performance spaces by the end of the year.
Originally known as Project Under Gardiner and facilitated through a $25-million donation from philanthropists Wilmot and Judy Matthews, the four-hectare space will run 1.75 kilometres between Strachan and Spadina Avenues, connecting seven downtown neighbourhoods with a total population of 70,000 people. It will link up with such recently completed and proposed projects as the Fort York Visitor Centre, public facilities at CityPlace, the William G. Davis Park and Trail and the Lower Garrison Creek Park and Trail.
Key features will include the skating/walking trail, a performance space at Strachan Avenue with bench seating for 250 people, another lawn amphitheatre to seat 500, an extension of the Fort York Visitors Centre to house skating refrigeration infrastructure, extensive art displays, landscaping and links to existing walkways.
Construction to accommodate underground utilities including water, sewer and stormwater pipes began in April with substantial completion of the whole project expected next June, though it is contemplated that additions to accommodate newly created programming ideas will extend the timeline.
Waterfront Toronto senior project manager Shannon Baker described a construction management structure that she said is new and innovative but working smoothly.
Kiewit is the construction manager. The funding party, the Matthews Foundation, and the future administrator, the Bentway Conservancy, are actively involved in overseeing the project as it is being built out, she said, while the City of Toronto as the owner and Waterfront Toronto as the delivery agent play central roles.
Designer Ken Greenberg and landscape designers Public Work are also integral players. Artscape, a cultural consultant, also plays an ongoing role as programming ideas become incorporated into the build.
"It is important to keep everyone involved in how the project is developed," said Baker.
"The way it is set up, Kiewit is the construction manager. That type of delivery model was chosen for its efficiency and for the effectiveness of the project because there was such a drive to have the project finished within a certain time frame, because everyone is so excited about seeing the project come to fruition."
The Bentway is named after the support columns, or bents, holding up the expressway.
The Gardiner, of course, is the star of the space. Kiewit project manager Navid Ganji noted the expressway plays a practical role during construction keeping rain off the worksite.
Even with wet weather this spring and summer, Ganji said groundwater has not been a major issue for the constructors. There was, however, a soil problem unexpectedly encountered during excavation for the skating building that required a change of plans.
"We were excavating and we encountered soft soil conditions," he said.
"It's adjacent to the slope, the Fort York grounds are at a higher elevation, and we had to install shoring in support of excavation, so we quickly mobilized with the foundations contractor to install a soldier piles and lagging system and we were able to quickly work through that and get back on track."
Overall, water management is a good story, said Baker.
"One of the innovation pieces of this project from a stormwater and water management perspective is that it integrates bioswales and water retention systems into its stormwater approach, and it also manages the runoff from the Gardiner Expressway, so the stormwater system for our site will be incorporating that runoff and using bioswales and Brentwood tanks to collect stormwater and to manage it before outletting it into the city's stormwater system," Baker explained.
The outcome will be improved water treatment and quality, said Baker.
The water works and underground utilities will be completed this month, Ganji indicated. It was a major concern during the design phase late last year that there might be unexpected utilities uncovered during excavations, he said, so a subsurface utilities investigation company was engaged to investigate, test and document the underground spaces.
By the end of phase one, this December, the bleachers at Strachan, the skating trail with coolants piped underfoot, the skating building and the lawn amphitheatre are expected to be completed; the second phase including decking, lighting, furnishing and landscaping will be completed in 2018.
Phased openings of new art spaces and the park infrastructure will be scheduled throughout 2017 and 2018.