Introduction
| The
Don is a 38 km long river that drains a 360
square kilometer watershed in Ontario, Canada.
Its headwaters are in the exurban Oak Ridges
Moraine and the suburban Peel Plain, a relatively
impervious till. The river ends in downtown
Toronto where it flows through the Keating Shipping
Channel into the Inner Harbor, and then into
Lake Ontario.
The Don’s streams and valleys still vary,
but most have been replaced with expensive engineering
intensive solutions. This is most evident in
the lower channel of the Don where it becomes
a classic urban river in a concrete canal. This
reach of the river is relatively straight, lacks
grade, and has no natural connectivity to the
floodplain.
This case study briefly presents three projects
in this lower section of the Don. The first
project is the mouth of
the Don, the second is a proposal for the
lower channel, and
the final project is the Chester
Spring's Marsh. It also presents what is
innovative about the
projects and closes with evaluation
of what is transferable or successful about
each project. |
 (TRCA) |
|
Infrastructure and Water Quality
The Don watershed used to manage water quality
through a network of streams, rivers, ponds, lakes,
and marshes. This infrastructure has been buried,
straightened, and lined with wood, steel, rock,
or concrete in the process of building the city
and suburbs. Overall, the watershed is 80 percent
urban and 70 percent of this development occurred
prior to stormwater management regulations. For
example, the map to the right shows the high concentration
of storm sewer outfalls in the lower channel of
the Don.
The cumulative impacts of the new infrastructure
are significant. Bacterial concentrations of 60
to 500 times the guidelines for recreational swimming
are routinely recorded in the Don's waters. Approximately
59,500 tons of seriously degraded sediment is
deposited and dredged annually from the the Keating
Shipping Channel, the artificial mouth of the
Don. |
(Hough 1993) |
| Toronto
and the Don: 1842, 1873, 1910
Mapped below is the Don's relationship with the
City of Toronto. In 1842, the Don is a meandering
edge to the city. In 1873, the river retains much
of its pre-settlment condition--the rivers meanders
are still in place and so is Ashbridge's Bay,
the large wetland at the mouth of the Don, but
pollution in the river becoma a chronic source
of public health and flooding related concerns.
By 1910, the meanders have been channelized and
Ashbridge's Bay has been filled to create the
portlands, an industrial district. Today, the
Don has lost all of its presettlement character,
but much attention is being devoted to regenerate
the Don's postindustrial landscape. |
 (Careless
1984) |
 |
 |
| Who is working for the
Don?
It is hard to tell the story of the Don without
including its social and political infrastructure.
There are numerous organizations working to revitalize
the Don River--the City of Toronto, the Metro
Toronto Conservation Authority, the Toronto Waterfront
Revitalization Corporation, the Waterfront Regeneration
Trust--but the efforts of tireless citizen activists
have been the driving force behind improving the
Don's ecological and human health. The Task Force
to Bring Back the Don has been the primary organization
that channeled this bottoms up momentum into a
force of change.
The Task Force is a citizen's group that works
in support of the City of Toronto to regenerate
a healthy and accessible Don River watershed.
Central to its success is being able to work in
cooperation with public and private organizations
to broaden the support for the Don. The organization's
founding principles illustrate the goal of making
the Don a healthy place in which the residents
can enjoy urban life and experience nature simultaneously.
1. We want the Don to belong to the public
2. The river must become accessible
3. We must let the river return to a natural state
4. We want clean water, air, land
5. We would like the river to be seen, in the
minds of Torontonians, in its broader context
6. We want the Don to be seen in its geographic
context
Community organizing has been central to the
Task's Force success in establising political
support for its "many small acts of regeneration."
Such acts includes organizing nature walks, clean
up days, mass tree plantings, fund-raising, conducting
acquatic and terrestrial research, and activism
to improve the Don.
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