On this Earth Day, we honour those nurturing folks who have invested their energies into reviving our jewel of a waterway. How can we return the battered river to the caring arms of nature? These pictures show what can be achieved with a little imagination, even along the heavily degraded lower Don.
Don by the numbers
Total size of the Don River watershed: 360 square kilometres
Length of the Don: 38 kilometres
Percentage of the Don River valley that's forested: 7
Percentage of the valley that was forested before industrialization at the turn of the 20th century: 91
Number of trees and shrubs planted since restoration efforts began in 1991: More than 40,000
Number of areas within the Don watershed that have been designated as environmentally significant: 20
Number of wetlands created: 8
To create a web of wetlands and wildlife habitats from the Don's headwaters at the Oak Ridges Moraine to its mouth at Lake Ontario.
Why time is of the essence
Encroaching urbanization: Currently, 80 per cent of the Don watershed is urbanized. By 2021, the figure will be 91 per cent. More people means more pollution.
A history of decline
1793: Mills, quarries and factories begin lining the Don's lower reaches.
1850: Spread of gasworks, petrochemical and other heavy industries follows.
At the end of 19th century
A section of the Don below Gerrard is straightened to halt damage to buildings and bridges caused by annual spring flooding and to open a shipping channel and provide room for rail lines and roads.
Ashbridges Marsh, a 6-square-kilometre wetland teeming with wildlife at the mouth of the Don, is drained and landfilled to create more space for industrial development in the port lands.
After the second world war
The Don Valley Parkway and Bayview extension are built through the valley, without regard for geological or natural features, to service the new suburbs of Don Mills and Scarborough.
Heavy industry departing the valley for greener pastures leaves behind pollution and contaminated soil.
1954: Hurricane Hazel causes death and destruction but also proves a godsend when the provincial government responds by banning future development in the Don flood plain, preserving what's left of the valley's natural space.
The 50s and 60s
Much of the valley remains an urban wasteland, inaccessible, cut off by storm fences and used for little except to dump garbage and store city equipment.
1969: Pollution Probe holds a mock funeral for the Don, reigniting public interest in valley preservation efforts.
1989: A public meeting on the future of the Don leads to the appointment by city council of a citizen task force to Bring Back the Don.
Major restoration efforts
Don Valley Brick Works: A quarry and factory that supplied the bricks to build the city has been transformed into wetlands and wildflower meadows, with boardwalks and interpretive signs.
Chester Springs Marsh: A former landfill covering three hectares just south of the Bloor Viaduct now plays a major role in regulating the Don's water quality by cleansing unwanted pollutants from runoff.
Riverdale Farm Ponds: Nearly 2,000 trees and 3,000 wildflowers and other wetland flora were planted in this naturalization project that provides habitat for local and migratory birds as well as viewing platforms for educational purposes.
Beechwood Wetland: After years of disturbance from oil and gas and industrial activities, 50 centimetres of topsoil was removed from this site to create a more varied topography, and 6,500 native trees were planted to replace invasive species choking native plant life.
Weirs have been modified along the Don to allow salmon to reach spawning grounds upstream, making possible the largest migration of salmon in more than a century.
Large sections of the Don watershed have been extensively replanted in an effort to create natural wildlife corridors, the most significant the 15-kilometre-long Bartley Smith Greenway.
Encouraging signs of life
Renaturalization efforts have attracted larger wildlife like great blue herons, beavers, muskrats, snakes, wood ducks and even deer. But more exciting for Don lovers is the presence in wetlands of benthic invertebrates, bottom-dwelling organisms that are an important link in the food chain for fish and waterfowl and indicate that the Don's water quality is improving.
Combined sewer systems in older parts of the city continue to spew untreated sewage directly into the Don when they overflow.
Greater runoff caused by erosion warms river water to temperatures intolerable for many fish species.
Invasive plants like dog-strangling vine, knotweed, purple loosestrife and Norway maple continue to spread, crowding out native vegetation.
Redevelopment plans for derelict lands along the west Don and upstream on the Oak Ridges Moraine - "Toronto's rain barrel," whose rolling hills and porous gravels cleanse some 30 Ontario rivers - threaten the valley.
Heavy off-track use by cyclists exacerbates erosion problems.
Plans for the future
Major plans are afoot to renaturalize the lower Don and Keating Channel by recreating the marsh that once teemed with wildlife at the mouth of the river. Broader naturalized green space will be brought back along the river's edge. This "centrepiece of the port lands" includes rerouting a section of Lakeshore Boulevard further south to create "a place of mystery, discovery and spiritual rejuvenation; a place to feel the fresh mud... amid the hum and bustle of city life."
Sun Valley tree and shrub planting, Saturday, May 1, across from the Beechwood Wetland. Access from the Lower Don bike trail or from Beechwood Drive, off Pape. 416-392-5323.
Paddle the Don, Sunday, May 2, 9 am to noon, from Ernest Thompson Seton Park (west off Leslie, north of Eglinton). Pre-register at 416-661-6600 ext 5283.
Crothers' Woods spring tour, Saturday, May 8. Meet in the Loblaws parking lot at Redway Road.
19th annual Don River Walk, Sunday, May 9, noon to 3 pm, from Chester Springs Marsh to the Don Narrows. Rain or shine. 416-392-0401.
Bring Back the Don meet-and-greet spring event, Sunday, May 16, 2-6 pm, Mill Street Brewery (55 Mill). 416-392-0401.
Bike Week Don trail tour, Sunday, May 30. Meet at the Riverdale Park East wetland (north end of the park). 416-392-0401.