Toronto wants to free the Don River from its concrete corset.
The city's eastern river, which often resembles a plugged and polluted drainage ditch, could be turned back into a more natural state, according to a plan to be unveiled next Wednesday at a meeting of the Task Force to Bring Back the Don.
A marsh alive with plants and wildlife is envisioned to replace vacant oil-stained fields beneath the Gardiner Expressway. The original marsh at the mouth of the river was filled in nearly a century ago as part of an unfinished plan to create a barge canal to Northern Ontario.
The new plan calls for eliminating the Keating Channel, which now creates a silt-collecting dogleg at the end of the river. Lake Shore Boulevard could then be moved south to where the channel now runs.
This would create a space of about 15 hectares, much of it formerly covered with oil-storage tanks, which could be restored. The river would be allowed to flow in a more natural sweeping curve lined with cattails, shrubs and shallow ponds.
"I think this dream will work. It makes sense to have marshland rather than the whole mess at the end of the Don," said Michael Hough, a landscape architect preparing concept sketches to be presented on Wednesday.
The plan includes public walkways and will provide a gentle slope that will keep silt flowing toward the lake rather than having to be dredged annually out of the constricted river.
Over time, the Don would form a new delta at the eastern corner of the harbour, but Mr. Hough estimates that would take a century or more.
"Certainly this is something that should be done," said Tanny Wells, chairwoman of the Don task force, which has been studying a river cleanup for 10 years. "It will help with floodproofing. It will clean up the water before it goes into the lake, and it will be beautiful," Ms. Wells said.
There are still many unknowns, she said, including how much polluted soil has to be cleaned or removed.
A consultant is still forming an estimate of the cost for rebuilding the large area, which is likely to be at least as high as the $38-million estimated for a 1994 proposal to restore the Don to its original channel. Where the river flowed a century ago industries are now situated that would have to be moved.
The latest plan is a compromise that is smaller in scope, and most of the land is owned by the city and now vacant. Still, there are multiple problems with a site so crisscrossed by roads, pipelines and rights of way, Ms. Wells said. Pieces of the land are owned by two city departments as well as the province. The railroads are also affected, although the rail lines won't have to be moved.
"We're pretty excited that it is on the front burner," said Ms. Wells, who feels confident the time is right to try to make it happen.
The naturalization of the mouth of the Don is included in Toronto's vision for the waterfront and another plan for redevelopment of the port lands and is also mentioned in plans for the city's bid to host the 2008 Olympic Games.
The challenges are still formidable, said John Wilson, an executive of Pollution Probe and vice-chairman of the task force.
"There are some pretty nasty toxins there because it was a petroleum refinery and an oil-storage yard for 50 years. We still don't now what we'll find or where," he said.
While the new mouth of the river would be considerably smaller than it was when the land was filled in early in the 1900s, it is still a large area for an urban river, he said.
"Can it be maintained? I think so," Mr. Wilson said, noting that San Diego successfully restored a river in a similar industrial zone.
"I am optimistic that something wonderful can happen. I would see a series of little marshy ponds and a meandering river."
The scene would change with time as sedges, cattails and shallow-water plants grow in. He believes ducks, cormorants, herons and other water birds similar to those on the Toronto Islands will make it their home.
Mr. Wilson said it is difficult to fault Toronto for filling in the river's original marsh. It was the dump for the city's raw waste and at the time was considered a public-health hazard.
The river's original mouth formed Ashbridges Bay, which stretched to the east as far as the Scarborough Bluffs. Most of it was filled in to become the industrial area known as the port lands on the eastern edge of today's harbour.