Europeans are settling and developing present day Toronto. The Don River flows into Ashbridges Marsh, one of the largest freshwater marshes on the north shore of Lake Ontario. This marsh is home to birds, mammals, reptiles, amphibians and fish.

Urbanization continues in the Toronto harbour. Hard to imagine today, it was very mucky and dirty. Gooderham & Worts Distillery establishes on the bank of the Don River, a booming distillery business along with cattle feedlots. Waste is disposed directly into the river and Ashbridges Marsh. The environmental conditions in the marsh are declining and by 1911 a decision is made to fill the marsh to create lands that will serve more economical purposes.

Filling of Ashbridges Marsh is mostly complete; the marsh habitat is long gone.

The St. Lawrence Seaway opens to improve commercial navigation through the Great Lakes. Toronto anticipates a boom in port activity and begins a new lakefilling project at the foot of Leslie Street to create land for port related infrastructure. Click the poster below to download the pdf.

The Baselands are constructed first, followed by the start of the ‘Spine Road’ (i.e. Multi-Use Trail). The fill material in these areas is made of brick and concrete rubble from demolition and construction sites across Toronto.

The peninsulas and embayments are created through a hydraulic dredge of the outer harbour. They are made of the sand-silt material from the lakebed that provide a different growing medium than the rest of the landform. Port activities have not taken off as anticipated in the late 1950s. The provincial government awards Toronto and Region Conservation the responsibility of developing a Master Plan for a public park on the lands.

With the binational Great Lakes Water Quality Agreement of 1978 new regulations were put in place for a minimum quality of material that could be disposed of in open water. Dredged materials from the lower Don River and Keating Channel did not meet these regulations, and as such, construction starts on three Confined Disposal Facilities that will permanently hold the contaminated sediments.

Trees and shrubs are establishing on the peninsulas. The Confined Disposal Facilities are built and the north cell, Cell 1, is filled to capacity. Lakefilling continues south of Cell 3.

The landform is nearing its final footprint. Lakefilling continues on the lakeside, north of the lighthouse to create the Toplands.

Lakefilling is complete. TRCA has implemented Master Plan phase I including habitat creation and enhancement projects, trails and buildings. The park is designated as an Environmentally Significant Area and an Important Bird Area. It provides critical habitat for wildlife and unique recreation opportunities minutes from downtown Toronto.

Junior Birders Camp
Aug 20 @ 8:00 am – Aug 24 @ 3:00 pm

young birdwatcher at Tommy Thompson Park

Send your young bird-lover to Junior Birders Camp for five days of exploring Tommy Thompson Park by bike, as we look for birds living in the park and those beginning their migration south.

Campers will hone their bird ID skills and learn from experts in the field about bird monitoring, sketching, and identification tricks. For ages 10 – 16.

Campers will use bicycles to travel around the park. Participants must supply their own bikes and helmets. Tommy Thompson Park offers indoor spaces in case of inclement weather.

Junior Birders Camp is led by professional environmental educators, with years of experience delivering programs for kids. A detailed information package will be sent to registrants, including information about what to bring and where to meet.

Need a more flexible start time for camp or have further questions? Email Raja at

Cancellation notices provided in writing at least 14 days before the start of camp will receive a 90% refund. Cancellation made within a 14 day period will not receive a refund. There is no refund for camp days missed.

August 20 to 24, 2018 
8:00 am to 3:00 pm (option to bring participants as late as 9 a.m.)

Early-bird pricing, until May 31, 2018: $240 (plus HST, if applicable)
After May 31, 2018: $275 (plus HST, if applicable)

Children (ages 10 to 13): BOOK ONLINE  »

Youth (ages 14 to 16): BOOK ONLINE  »

Cancellation notices provided in writing at least 14 days before the start of camp will receive a 90% refund. Cancellation made within a 14 day period will not receive a refund. There is no refund for camp days missed.