Prior to the 19th century, the Don River naturally entered Toronto Harbour in two mouths, one roughly near where Keating Channel now flows out and one further south. In the late 19th century, a public works program was started to straighten the lower part of the Don River south of the
Winchester Street Bridge. The project was called the "Don Improvement Project". The goal of the project was to alleviate floods on the lower Don that were periodically washing out bridges. It was also done to create additional wharf space for the Toronto harbour. When it was completed, the river was directed south into Ashbridge's Bay. At the time Ashbridge's Bay was still a lake-side (
lacustrine)
marsh. It was heavily polluted by local industry. The water from the Don river was diverted into the bay with the hope that it would flush the bay of the poor water. However the flow of river water introduced raw sewage into the bay. The bay water remained stagnant and was increasingly becoming a serious health risk. The Keating Channel was proposed as a method of directing the dirty river water into the harbour thus dispersing it more rapidly. The channel was planned to go from the northeast corner of the inner harbour east towards
Leslie Street and join up with the
Coatsworth Cut at the foot Coxwell Avenue. However, the portion east of the Don River was never completed and it was closed in 1916. The channel was completed in 1922 after eight years of construction. The completed channel now runs from the harbour east to the mouth of the river, a distance of about 800 metres. The original mouth of the Don is buried under infill near where the
Gardiner Expressway meets
Cherry Street. The original course from the mouth upstream now lies underneath railway tracks used by
GO Transit for storage. The channel is flanked on the north by the elevated
Gardiner Expressway and
Lake Shore Boulevard East. The south side is occupied by the
PortsToronto (also called the
Toronto Port Authority) works yard and the Keating Channel Pub. At the west end Cherry Street crosses the channel over a single-sided
drawbridge rarely used by ships. At the east end is the start of the
Don Valley Parkway. In the 1940s the
watershed further up the Don River became more urbanized. This caused an increasing amount of
silt to flow down the river. The silt collects in the channel where there is very little water flow. Since that time, the
Toronto and Region Conservation Authority (TRCA) has been
dredging the channel. The dredgeate material is barged out to the
Leslie Street Spit where it is dumped in a containment area built for this purpose. In 2005, the annual amount of silt dredged was about 35,000 cubic metres. The containment area has the capacity to take 50 years of Don River dredgeate . In 1980 Ontario's
Minister of the Environment was asked, during
question period, about an exemption from environmental regulations, granted to those who dredged the channel.
Member of Provincial Parliament (MPP) Bryden was quoting
Donald Chant's recommendation concerning the Keating Channel, and why the recommendation had been ignored, when she was interrupted by the Minister. Chant was then the chairman of the
Premier's steering committee on environmental assessment. According to the MPP, Chant's recommendations had questioned whether dredging the channel was worthwhile: ==Industry==