A History of Tommy Thompson Park

Human Ingenuity Meets Natural Resiliency

Tommy Thompson Park (TTP), situated in the heart of Toronto on the Leslie Street Spit, highlights the resilience of nature and human ingenuity.

This constructed peninsula serves as a unique example of urban coexistence with nature, illustrating our ability to harmonize with the natural environment and create something extraordinary.

TTP: A History

Before the establishment of the City of Toronto, the lands along the central waterfront were once composed of mixed forest and marsh ecosystems.

A 560-hectare marsh complex, known as Ashbridges Marsh, was located at the mouth of the Don River and provided habitat for hundreds of species of plants and animals.

The area was significant for Indigenous peoples and European settlers, offering rich biodiversity and resources for activities including fishing, hunting, trapping, boating, and ice skating.

1815 map of York Harbour by Joseph Bouchette
Map (1815) by Joseph Bouchette. Source: Toronto Public Library.
1793 painting of York Harbour by Caroline Simcoe
Painting by Caroline Simcoe (1793): Looking west from near the mouth of the Don River. Source: Digital Archive Ontario.

In the late 19th century, human activity, including waste disposal from nearby industries, resulted in the pollution and degradation of the marsh.

In response, the Toronto Harbour Commissioners was established in 1911 to create a modern port, industrial sector, and recreational areas.

They developed the Ashbridges Bay Reclamation Scheme, which saw the filling of the marsh by 1922 and the creation of 200 hectares of land for industrial purposes. It was the largest engineering project in North America at the time, and is known today as the Port Lands.

1904 black and white photograph of Ashbridges Marsh
City of Toronto Archives, Fonds 200, Series 376, File 4, Item 63. 1904.

Building the Spit

Following the growth of the city and with the opening of the St. Lawrence Seaway in 1959, a project was undertaken to expand the Toronto Harbour.

The Outer Harbour East Headland (aka the Leslie Street Spit) was constructed from the foot of Leslie Street to create additional sheltered water, known as the Outer Harbour.

Close to 9.5 million cubic meters of various materials, including rubble and debris from old buildings and subway construction, were used to create the land.

black and white 1959 aerial photograph of Leslie Street
Leslie Street, 1959 Source: Ports Toronto.

In 1973, dredging took place in the new Outer Harbour to achieve navigational depths for large watercraft and freighters.

The sand material removed from the bottom of the lake was deposited on the city side of the Spit, forming the peninsulas.

black and white aerial photograph of Outer Harbour East Headland under construction in 1969
black and white aerial photograph of Outer Harbour East Headland under construction in 1970
black and white aerial photograph of Outer Harbour East Headland under construction in 1973

Outer Harbour East Headland construction in (left to right): 1969; 1970; and 1973. Source: Ports Toronto.

Following the bi-national Great Lakes Water Quality Agreement in 1978, three confined disposal facilities were constructed on the lake side of the Spit. These facilities are used to store contaminated sediments removed from the Lower Don River and the Keating Channel.

Today, two are full and have been decommissioned with a cap to isolate the contaminants, and wetlands have been created at the surface. Cell 3 remains an active confined disposal facility.

The Creation of Tommy Thompson Park

By the early 1970s, it became evident that the Leslie Street Spit was no longer essential for port-related industries, as changes in shipping practices resulted in less substantial growth in port activity than anticipated.

In weighing options for the future for the Spit, parkland use emerged as the obvious choice. Metro Toronto and Region Conservation Authority – now Toronto and Region Conservation Authority (TRCA) – was charged with developing a Master Plan and implementing an interim management program.

In 1984, the Spit was officially named Tommy Thompson Park, in honour of Toronto’s first Commissioner of Parks.

While the original concepts for the park had focused on active recreation and boating, environmental conditions had changed drastically since the initial planning, so a greater emphasis was placed on the natural environment.

The Revised Tommy Thompson Park Master Plan, approved in 1995, owes its complete focus on the natural area to the dedication and persistence of local advocacy and interest groups, such as Friends of the Spit and Toronto Field Naturalists.

Aerial view of Tommy Thompson Park in 2013
Aerial view of Tommy Thompson Park, 2013.

Today, Tommy Thompson Park is focused on preserving significant species, protecting environmentally significant areas, enhancing habitat, and providing recreational opportunities such as bird watching, walking, jogging, and cycling.

Since 1995, TRCA has created, enhanced, and restored over 70 hectares of aquatic and terrestrial habitat at the park.

Through these efforts, coupled with natural succession, TTP has evolved into an Environmentally Significant Area and a globally significant Key Biodiversity Area, returning some of the habitat lost from Ashbridges Marsh to the waterfront.

view of the Toronto skyline from Tommy Thompson Park
Tommy Thompson Park and the Toronto skyline.

Today, as visitors walk the trails and witness TTP’s thriving ecosystems, they may not be aware of the many twists and turns that led to its creation – a saga spanning decades of restoration efforts, differing visions for the future, and ultimately, a model of environmental stewardship.

Above all, TTP reflects what can be achieved through a collective commitment to a greener, more sustainable future.

Watch this “TTP Talks” webinar to learn more about the creation of Tommy Thompson Park: