Wetland Creation Project at Tommy Thompson Park


Pedestrian trails, nature trails, lookouts and a recreation node will be open for public use in spring 2018!

This project is supported by the Government of Canada through the Canada 150 Community Infrastructure Program.

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Cell 2 Confined Disposal Facility Restoration and Wetland Creation Project

There are three confined disposal facilities (CDFs) or cells at Tommy Thompson Park that were created to contain the contaminated materials dredged from the Keating Channel and the Inner Harbour. Cell 1 was filled to capacity in 1985; it has since been capped to isolate the contaminated sediments, and a wetland was created above. Click for more information about the Cell 1 Wetland Creation Project. Cell 2 was filled to capacity in 1997 and the CDF Restoration and Wetland Creation project is now underway.

Existing Conditions

Cell 2 is a 9.5 hectare CDF that is largely of uniform depth and lacks substrate diversity and cover. The shoreline is steep, lacks riparian cover and has low structural diversity. These conditions do not provide adequate opportunities for reproduction and foraging for fish and other wildlife. Further, the dredged sediment in Cell 2 contains contaminants that do not meet Canadian Environmental Quality Guidelines and could provide a threat to fauna that live or spend time in the cell.

Project Description

Cell 2 will be capped with clean fill to physically and biologically isolate the contaminated sediment from the ecosystem, thereby improving water and sediment quality. A 9.3 hectare coastal hemi-marsh ecosystem will be created to restore fish and wildlife habitat to the cell. In-water, shoreline and riparian treatments will focus on providing a diversity of habitats to allow fish and wildlife species better reproductive, nursery, foraging and overwintering opportunities.

The ecological value of Tommy Thompson Park will continue to increase dramatically as the habitat communities mature, and as the lands are improved through new and continuing restoration projects. The conversion of the Cell 2 CDF to a 9.3 ha wetland complex provide long term conservation benefits and will further enhance the ecological value of the site as a biological centre of organization within Toronto. Additionally the site will provide Torontonians with increased recreational opportunities. Bird watching, nature appreciation and angling are all activities that will be encouraged at the restored Cell 2 wetland.

Implementation Timeline

The capping and wetland creation is scheduled to take 3 years to complete. Construction will begin late 2014 and should wrap up in winter 2017-18.

Habitat features will include deep pockets for overwintering fish and herpetiles; in-water shoals, root wads and other submerged structures for fish reproduction; nursery and foraging habitat; aquatic emergent and floating vegetation areas; islands for Common Tern nesting and turtle nesting; an isolated area for amphibian reproduction; a robust riparian area with meadow and shrub vegetation communities; and a fish and water level control structure to prevent large common carp from entering the wetland and damaging the habitat. Since the establishment of emergent vegetation is sometimes difficult, management of the site will be adaptive in its nature to ensure success. Techniques to ensure success include fencing to protect newly planted vegetation from herbivory and silt fencing can be added to fenced vegetation quadrants to improve water clarity if required.

Project Partners

The Toronto and Region Conservation Foundation (formerly The Living City Foundation) and Toronto and Region Conservation Authority (TRCA) graciously acknowledge the contributions of our partners. If you are interested in contributing to this innovative wetland creation project please contact us!

City of Toronto | Coca Cola Bottling Company | Environment and Climate Change Canada | Fisheries and Oceans Canada | PortsToronto

For more information please contact Karen McDonald at kmcdonald@trca.on.ca or 416-661-6600 ext. 5248

Cell One Wetland Creation Project

The three confined disposal facilities (CDFs) or cells at Tommy Thompson Park were created to contain the contaminated dredging material from areas within the Inner Harbour. Eventually the CDF becomes too shallow for the barge to enter and deposit the dredged materials. Cell One was filled to capacity in 1985 and plans were initiated to create a wetland.

The Cell One capping project began in 2003 with the draining and capping of the north end of the cell. Traditionally, when CDFs are capped the land created is terrestrial; however, Cell One is an innovative “wet cap”, meaning that after the cell was drained and clean fill placed over the dredgeate to contain contaminants, the cell was graded to create the correct contours needed for the establishment of a healthy wetland and water was pumped back into the cell. The primary goal for the Cell One Wetland Creation Project is to create a wetland that supports functional fish and wildlife habitats and contributes to the ecological integrity and biodiversity of Tommy Thompson Park. To achieve this goal additional grading was undertaken to attain proper slopes and shoreline conditions; different substrates and structures were added to increase functional habitat; critical habitat features targeted for certain species were installed and various terrestrial and aquatic plants were planted.

Construction of Cell One was completed in 2005, however both aquatic and terrestrial planting continues and habitat features are still being modified. This 11.5 hectare complex of terrestrial and aquatic habitat includes a 7.7 hectare coastal hemi-marsh that is the largest wetland gain in the Toronto waterfront. Cell One is already providing functional habitat for a wide variety of fish and wildlife species. Juvenile fish species, as well as adults have been recorded in the completed Cell One wetland. The newly created tern island was home to almost 300 nesting pairs of Common Terns in 2005 and a created Bank Swallow habitat hosted a colony just days after completion. Depending on water levels shorebirds are often seen foraging in exposed mudflats during migration. Midland painted turtles and Northern map turtles have been observed in and around the cell. Muskrats and mink have also been documented foraging in Cell One. The site also marks the reintroduction of native wild rice communities on to the Toronto waterfront.

The environmental monitoring program for Cell One is extensive and includes sampling sediments, water, benthic invertebrates and fish and wildlife surveys. For more information on environmental monitoring at Tommy Thompson Park please click here.

Carp attempting to enter a wetland at Tommy Thompson Park

This fish and water level control structure was installed in spring 2011 to prevent non-native common carp from accessing the Cell One wetland. The structure allows all fish, except large carp, access to the wetland. Carp destroy wetlands through their spawning and foraging behaviours by uprooting vegetation and creating murky water conditions that limit plant photosynthesis. This video, shot in May 2011, shows carp trying to access the wetland to spawn. The high lake level made jumping over the first gate possible for a few individuals, but none were able to jump over the second gate. Smaller carp that access the wetland cause less damage and they exit the wetland before winter freeze up. Please NEVER transfer fish from one waterbody to another, especially carp.