PortsToronto is in the process of removing up to 40,000 tons of debris and sediment from the mouth of the Don River, with the goal of preventing future flooding and stemming the flow of unwanted material into Toronto’s Harbour which can pose a risk to boater navigation and public safety.
Each year, thousands of tons of sediment build up where the Don River empties into the Keating Channel which, if not removed, could cause the river to backup and flood, or, in some cases, debris to spill into Toronto’s Harbour. As stewards of the waterfront, PortsToronto, in conjunction with the Toronto Region and Conservation Authority (TRCA), provides the important service of removing the sediment in a process called “dredging” which helps to maintain a river depth that allows for the smooth flow of water and ice through the Keating Channel.
The dredging process involves scooping large amounts of material from the bottom of the channel using a clam bucket on a machine called a “dredger.” Once removed from the channel bed, the muddy mixture of debris and sediment is then transported by barge to the Leslie Street Spit (the Spit) for proper containment in what is called a “cell” or Confined Disposal Facility.
The Spit features three “cells,” all of which were designed by PortsToronto to properly and safely contain dredged material. As each cell reaches its capacity for dredged material, PortsToronto seals it with a layer of soil and clay – which is then innovatively used by the TRCA as a base upon which to build acres of new wetland habitat for fish, birds and wildlife.
The first cell, “Cell 1,” was converted into wetland in 2013, successfully resulting in a new home for marsh birds, including nesting Common Terns, turtles, amphibians, small mammals and native fish. In September 2016, PortsToronto, together with TRCA, completed work on “Cell 2” to provide a second nine-hectare habitat that will benefit fish, migratory birds and various other species of wildlife. The final cell, “Cell 3,” continues to be used for dredged materials, with approximately 30 to 40 years of capacity remaining.
PortsToronto dredges on an annual basis and removes between 20,000 and 40,000 cubic metres per year from the mouth of the Don River. The current dredging is scheduled to continue for approximately eight weeks, through to the middle of November.
Additional information about the wetland creation project is available at: www.tommythompsonpark.ca/cell2