HTO Park

Challenge

As the first park to be developed on Toronto’s downtown waterfront, HTO’s most significant challenge was an almost complete lack of design or regulatory precedents for the development of public space on contaminated brownfields within the city of Toronto. However, the two main design priorities were to create a destination park on the waterfront and to address and remediate the environmental damage caused to the site by its industrial past. Another design challenge was emphasizing the value of the park’s proximity to the lake while discouraging direct contact with the water.

Solution

Although clear guidelines did not exist for the city at the time, the landscape architect reached out to nearby municipalities and contexts in order to understand precedents for how to address the complex challenges of the site. At the time of design and construction, traditional treatment of contaminated soil at the scale of a site on the Toronto waterfront consisted of either dig-and-dump, cleaning soil off-site, or capping the soil in place. Although capping typically costs as much as dig-and-dump per ton, two factors led to the decision to cap the site. First, the extent and composition of contamination on site was unknown, as several industrial uses had been there  before the site was paved over as a parking lot. Second, the high water table meant the soil was heavy, saturated with water, and would cost exponentially more to remove. Because the cost of removing contaminated soil would be beyond the budgetary scope of the project, designers decided to cap the site with additional soil to create a varied topography, which would both protect user health and create dynamic experiences and views within the park. As regulation prohibited water leaving the site while still contaminated, the stormwater management and irrigation systems were designed to hold and clean the water on site, rather than allowing it to flow into the lake untreated. To both connect the park to the water and maintain public safety, the design response was to change the edge condition, creating a wide boardwalk, and limiting access to the water.

• A series of 25 low rounded mounds create a sequenced experience within the park while safely capping contaminated soil. In total, the mounds contain approximately 5,250 cu yds of added soil – an adequate volume to support plant life.
• A total of 106 trees, 25 shrubs, and 3 types of grasses were planted in the park, including golden weeping willows (Salix alba ‘Tristis’), silver maples (Acer saccharinum), serviceberries (Amelanchier alnifolia), feather reed grass (Calamagrostis xacultiflora), purple silver grass (Miscanthus sinensis ‘Purpurascens’), and red switch grass (Panicum virgatum ‘Shenandoah’).
• The water’s edge is composed of 2 iconic elements; a “beach” of fine white sand, and 38 custom-made vibrant yellow all-season umbrellas.
• 5 large precast slab benches were placed along the edge of the grass and the beach to provide flexible seating.
• A 624-ft-long boardwalk was cantilevered over the water’s edge by 33 ft along the length of the site, allowing the construction of 19,160-sf of fish habitat within HTO and adjacent sites to encourage the return and proliferation of fish populations .Stones placed on the lake bottom under the boardwalk, along with a recycled concrete core, create the fish habitat and consist of 40% washed granular gravel (20-64mm), 30% cobble (170-250mm) composed of gabion and pit stone, and 30% boulders (larger than 250 mm) made up of riprap and small armour stone. This assemblage of stones offers space for aquatic plants to take root and increase shelter and improve foraging opportunities for fish.

As the first major public space to be built along the waterfront in years, HTO Park preceded Waterfront Toronto’s work, outlined below, and was funded by the city of Toronto. However, the park has an important role in the furthering of Waterfront Toronto’s plans as it was the first ‘new’ magnet for the waterfront, a district which has continued to grow and revitalize.

HTO Park is part of an ensemble of projects planned, designed and developed to rehabilitate and redefine the derelict waterfront of Lake Ontario as a new, vital district in downtown Toronto. This movement is part of a larger, coordinated effort to increase the environmental, social and economic value of formerly underutilized and restricted floodplain land that is being newly reintegrated into the city.

This ambitious urban endeavor has been almost entirely the work of Waterfront Toronto, an agency developed and funded by the federal, provincial, and city governments to revitalize the Lake Ontario shoreline. The agency’s strategy has been to create significant public spaces that catalyze the public and private development of new institutional, residential and commercial neighborhoods. Waterfront Toronto seeks to provide environmental, social and economic benefits within its area through its policies, such as its mandate that any development occurring adjacent to the parks include a minimum of 20% affordable housing. It also has its own Best Practice Guide for sustainability, which informs decisions about park design and maintenance. Residential, retail, office and institutional City Development Change fees are also applicable on development occurring around its projects to make funding available for future growth-related capital infrastructure. 

Traditional contaminated site soil treatment methods cost $24 million to dig the soil and recycle it off-site, or $25.3 million to dig and dump the soil. Instead, an estimated $22-23 million was saved by capping the site, which cost approximately $1.5 million. From the ground plane, the site was built up through the use of aggregate, concrete and varying soil dunes to cap the contaminated soil and allow safe use of the site. Capping the soil in place also avoided the 38,165 triple-axle truck trips that it would have taken to transport 534,308 tons of soil and debris off-site.

• The boardwalk design of HTO Park pushed the shoreline away from the former constructed edge of the lake, putting fish habitat at risk. To reconstruct some of this habitat, HTO uses a 19,160-sf base of reused and recycled construction materials. Because of the non-uniform materials, the design had to be open, with only approximate depths and material sizes specified. The constructed habitat has been successful, encouraging the return and proliferation of fish species, seeing an almost twofold increase in fish species types and triple the fish population. As a result of the experience at HTO park, city guidelines have been developed for the construction of fish habitats along the shoreline.
• The HTO design, which sought to invite people to the water’s edge without walls or bollards and chains, was previously unheard-of in Toronto’s downtown industrial core for reasons of risk management. The resulting design was allowed because a supportive city council member pushed for it and brought insurance companies into the process to establish guidelines for coverage for this new park type in Toronto. Precedents set by beaches to the west and east of the downtown core were also examined. As a result, steps down to the water were allowed. Utilizing ring buoys along the lake edge allowed for an acceptable level of risk for safety and water navigation, Additionally, the proximity of a fire station (and therefore water rescue boats) added a level of safety.

Stone Pavers: Ebel Quarry, Wiarton Stone paver units, beige pebble top finish
Waste Receptacle: Escofet, Morella bin series
Stone Benches: Escofet, Socrates stone bench series
Precast Slab Benches: Sky Cast Inc
Bicycle Racks: DRP Enterprises, Stainless steel wave bike rack
Umbrellas: Landscape Forms, Solstice Collection
Bollards: Urbaco USA, Vendome Stainless Steel bollard (fixed and removable)
Power Outlets: Midwest Electric, Dockhand metallic power outlet pedestal
Drinking Fountain: Most Dependable Fountains, 440 Direct bury stainless steel drinking fountain

Project Team

Landscape Architect: Janet Rosenberg & Studio Inc.
Landscape Architect: Claude Cormier Architectes Paysagiestes Inc. 
Architect: Hariri Pontarini Architects
Art Consultant: Rina Greer
Communications Consultant: Beth Kapusta
Contractor: Somerville Construction
Engineer: Carruthers & Wallace Ltd.
Engineer: Stantec Consulting Ltd.
Historian: William Greer
Lighting Designer: Leni Schwendinger Light Projects Ltd.

Role of the Landscape Architect

The design team, composed of two landscape architecture firms and an architect, worked closely with the client, the City of Toronto, as well as consulting specialty designers. The process included the primary landscape architect engaging in extensive public consultations in order to work with the city to create and deliver one of the first constructed urban beaches and public parks along Toronto’s still-developing central waterfront.