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Lower Don River West Remedial Flood Protection Project

This undertaking is producing a flood protection solution that will eliminate the risk to life and property to ~210 hectares of land west of the lower Don River.

This undertaking is producing a flood protection solution that will eliminate the risk to life and property to ~210 hectares of land west of the lower Don River. Through the use of computer models, this area has been identified as being within the Regulatory Floodplain, which is defined as the area of land that is anticipated to be flooded if a storm the size of Hurricane Hazel were to occur over the Don Watershed. Currently, two levels of development restrictions have been placed on the flood prone lands west of the Don River: Special Policy Areas (SPA) and Holding 'H' Areas.

Lower Don River West Remedial Flood Protection Project Study Area

Approximately 172 hectares have received a SPA designation, which allows new development to occur after appropriate flood proofing measures have been approved and incorporated into the design. The remaining 38 hectares, located immediately west of the Don River between the CNR bridge and Queen Street (which are known as the West Don Lands), possess an 'H' designation. Due to the very high degree of risk to flooding, this designation prevents any redevelopment to occur until a comprehensive flood protection solution for all 38 hectares can be implemented.

Flooding west of the Don River, resulting from a storm the size of Hurricane Hazel, would be enhanced by the damming effect of a too-narrow stream crossing under the Canadian National Railway (CNR) and other utility bridges, and the absence of a confining valley around the Don River. High water levels in Lake Ontario and ice jams during the winter and spring could also exacerbate the degree of flooding. Additionally, any flood protection solutions devised in the West Don Lands need to consider options to treat contaminated soils and groundwater within the area, which resulted from past industrial activities.

This undertaking is located in the heart of Toronto. As such, many cultural, social and economic issues had to be addressed to design flood protection for this area when it comes to devising a design that will provide flood protection for Toronto. Railway operations and infrastructure, land use planning, municipal infrastructure, recreation, the natural environment, the local economy, and public health are issues that were examined through the environmental assessment process.

Project Objective

The objective for the Lower Don River West Remedial Flood Protection Project is to protect human life and infrastructure from flooding by permanently removing approximately 210 hectares of Toronto from the Regulatory Floodplain, west and north of the Don River Mouth.