Cell One Wetland Creation Project

The three confined disposal facilities (CDFs) or cells at TTP 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.

Cell 1 A  cell 1 B

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.

cell 1 C  cell 1 D

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 TTP 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.


Tommy Thompson Park Habitat Restoration

Natural Area Enhancement Plan

Cell 1 Watershed Creation Project

Other Restoration Projects

Hours of Operation

Tommy Thompson Park is open to the public weekends and holidays, except Christmas Day, Boxing Day and New Year?s Day. Operating hours are 9 a.m. to 4:30 p.m. from November to March and 9 a.m. to 6 p.m. from March to November (coinciding with daylight savings time).



Tommy Thompson Park (TTP) is located at the base or foot of Leslie Street where it meets Unwin Avenue, south of Lake Shore Boulevard East.



Lake Ontario moderates TTP?s climate, with less heat & humidity in the summer and less snow in the winter than areas immediately north. Prevailing winds are westerly, with faster speeds and greater wind chill effects. Fogs forms twice as often at TTP than the rest of Toronto.