Bentway Leckie-Lake Shore Triangle (LLT) Staging Grounds

Toronto, Canada

In partnership with the City of Toronto, the Leckie-Lake Shore Triangle (LLT) site features a long-term development plan to provide open public spaces including a dog walking park, enhanced circulation, and new connections to the waterfront.

The most innovative experiment has taken an unused and polluted stretch of land beneath a raised highway to create a new public space, complete with planters and interpretation screens to educate the community around climate change and biodiversity issues. Opened in September 2023, visitors are invited into a “living laboratory for urban ecology”, with experimental gardens that use rainwater runoff from the highway above to support the growth of flowering plant species.

Bentway Staging Grounds is a temporary installation that unlocks an expanded public realm and programming opportunity for a city centre neighbourhood in Toronto.

The project seeks to use the site as a testbed for climate-ready urban design that integrates environmental benefits with the creation of new public realm.

Our experts conducted hydrologic analysis and provided technical advice related to stormwater retention, rainwater filtration and material design.

Self-watering stormwater planters support the management of runoff from the expressway, while providing education on water filtration, retention and plant growth.

Challenge

Bentway Staging Grounds is a temporary installation that unlocks an expanded public realm and programming opportunity for the CityPlace/Fort York neighbourhood in Toronto.

Through its Under Gardiner Public Realm Plan, the Bentway Conservancy has created a model for converting underused transportation islands beneath the Gardiner Expressway into productive, engaging, and accessible public spaces that bring communities together.

In this first phase of the LLT development, the Bentway Conservancy sought to use the site as a testbed for climate-ready urban design that integrates environmental benefits with the creation of new public realm. Physical conditions at the LLT site, such as the annual “highway flush”, which introduces sludge and debris to the project area, the limited sunlight coverage throughout the space, and the poor soil quality which constrain the uses of the site, all had to be contended with and solutions needed to be integrated into the design of the stormwater planters. The ground soil itself is contaminated by previous industrial usage, meaning that longer term remediation work will need to take place, with large planters being used as a short-term solution.

Solution

Designed by Agency — Agency (New York City) and SHEEEP (Toronto), with specialist water engineering and environmental advisory input from Buro Happold, graphic design by Neil Donnelly Studio, and horticultural consulting by Brother Nature, Bentway Staging Grounds collects and leverages runoff water from the highway above to irrigate oversized planters in the space below. These planters support the growth of diverse, flowering native plant species such as Milkweed, Agastache and Yarrow, while passive water filtration and retention helps to reduce the risk of local flooding.

The design introduces a network of ramps and elevated walkways that allow visitors to travel deep into the space as an extension of Canoe Landing Park to the north.

Working closely with the client and the wider design team, Buro Happold conducted hydrologic analysis and provided technical advice related to stormwater retention, rainwater filtration and material design, culminating in the design of self-watering stormwater planters to manage runoff from the Gardiner Expressway above, while providing opportunities for public education on climate action, stormwater management.

Our team integrated a filtration system to each planter, which removes debris, waste and pollutants from the water.

Bentway Staging Grounds is an interim intervention that will remain in place until the City of Toronto’s Gardiner Expressway Rehabilitation work commences in the area (currently scheduled for late 2025). This will include longer term soil remediation work, which could allow the new public realm to be more permanently expanded.

Over the project’s two-year duration, the Bentway Conservancy will commission artists to present original, rotating artworks on a series of scaffolding towers set to line the site facing Lake Shore Boulevard. 

Buro Happold calculated local rainfall accumulation patterns and water-flow rates from individual Gardiner Highway downspouts. They also assisted us to develop bespoke solutions for native ecologies, from the type of aggregate used to filter heavy metals to the thickness of soil required for drought-resistant plantings. The knowledge and foresight provided by the Buro Happold team created a foundation for our design to excel in unknown territories.

Jake Rosenwald, Agency—Agency

Value

Bentway Staging Grounds is a new type of public infrastructure that blends art and education, public space and experimentation, repositioning the Gardiner as a site of environmental regeneration.

The project continues the Bentway Conservancy’s ongoing efforts to transform the expressway into a better connector for pedestrians and cyclists. It delivers a piece of vibrant placemaking that will play a role in the wider regeneration of the neighbourhood, responding to the dynamic conditions of the site and educating visitors about urban ecology and stormwater management. Our team of experts delivered insightful guidance on how the innovative vision could be realised – creating new public realm beneath a busy expressway at the heart of the city.

Buro Happold’s expertise in developing the experimental garden prototypes provided us with an arsenal of tools we did not know were even needed. Starting with a range of precedent references, we worked with Buro Happold’s team to develop a conceptual model for remediation that could be deployed throughout our site.

Jake Rosenwald, Agency—Agency