The Lower Don Lands is a 125 hectare (308 acre) area that runs from East Bayfront (the Parliament Street Slip) east to the Don Roadway and from West Don Lands (the rail corridor) south to the Ship Channel. Waterfront Toronto plans to transform the largely underutilized industrial area into new sustainable parks and communities. The naturalization and shifting of the mouth of the Don River is the centrepiece of the plans for the Lower Don Lands.

The plans would see the Don River's mouth moved from its current location at the Keating Channel on the eastern side of Toronto’s inner harbour. The river would be re-routed through

the middle of the Lower Don Lands between the Keating Channel and the Ship Channel. This would result in the Don River once again becoming a major feature of Toronto’s waterfront and the centrepiece of new mixed-use neighbourhoods and parks and green spaces in the Lower Don Lands. The changes to the river mouth would also provide the flood protection necessary to enable development of the immediate area and the larger Port Lands.

Waterfront Toronto’s plans were developed through a comprehensive environmental assessment process which has included the examination of several alternative planning solutions. The plans are rooted in planning designs developed by Michael Van Valkenburgh Associates as part of the international design competition for the Lower Don Lands held by Waterfront Toronto in 2007.

Waterfront Toronto’s plans to transform the Lower Don Lands and renaturalize the mouth of the Don River are now official and binding. In August, Toronto City Council unanimously passed an Official Plan amendment for the Lower Don Lands and a new zoning by-law for the Lower Don Lands first precinct, the Keating Channel (West). The Official Plan Amendment paves the way for future revitalization of the area including rerouting the river, building flood protection and ultimately building new communities.

Until now, regeneration and development of the Lower Don Lands have been hindered by a number of factors including flood risk, isolation from the rest of the city, soil and groundwater contamination and insufficient infrastructure. The Lower Don Lands plans address and overcome all of these factors, and will transform this post-industrial area into a sought-after destination to live, work and play based on design excellence, ecology and economic sustainability.

The plans renaturalize the mouth of the Don River by rerouting it through the Lower Don Lands and at the same time protect more than 230 hectares (568 acres) of land currently at risk due to flooding. They also allow the current channelization of the river mouth to be reimagined as a dynamic urban canal neighbourhood. The flood mitigation measures in the plan eliminate a potential half-billion dollar flood risk, while simultaneously unlocking the economic development potential for the area.

Much of the Lower Don Lands is located in the Port Lands which was once the largest natural wetland on the Great Lakes. The Ashbridges Bay Marsh was created by the lower Don River as it emptied into Toronto’s inner harbour. The landscape in the area was dramatically altered in the late 19th and early 20th centuries. The Don River and the marsh it created posed many problems for the adjacent settlement of York and starting in 1870 a series of breakwaters, channels and other man-made structures were created to manage the area. Most failed or caused additional problems and in the 1910s plans were developed to change the area permanently.

In 1912, the Board of the Toronto Harbour Commission completed a plan for transforming Ashbridges Bay Marsh into a massive new industrial district with waterfront parks and summer homes. The mouth of the Don River was redirected into the concrete-lined Keating Channel in 1914 and infilling of the surrounding wetlands began. By 1922, more than 200-hectares (500-acres) of land had been created on the former marsh, with another 200-hectares soon to follow. These lands were quickly occupied by industry and plans for a major waterfront park and adjoining cottage community were never realized. After the Gardiner Expressway was built in the 1950s, the mouth of the Don River became lost amidst a tangle of off-ramps, bridges and abutments. Access to the river was virtually cut off. Over the past three decades, public calls for the naturalization of the mouth of the Don River have grown steadily stronger.