Toronto Tree Canopy and Waterfront Project

In 2019, the City of Toronto submitted the Tree Canopy and Waterfront Shoreline Project, in collaboration with the Toronto and Region Conservation Authority (TRCA), to the Disaster Mitigation Adaptation Fund, to support the city’s efforts to adapt to increasing and intensifying weather events and reduce the impacts of natural disasters such as flooding. This was done in response to significant erosion and damage that had occurred to the shoreline during the 2017 high lake level event and April 14-15, ice storm event. The federal government contributed $11.9 million through the fund and the City of Toronto another $17.9 million to cover the costs of the project which include; repairs and enhancements to shoreline erosion control infrastructure, remedial flood protection, path/boardwalk repairs, and an expansion of the City’s newly planted tree program to increase tree maintenance and natural area restoration. The City’s proposal recognizes that healthy trees provide an essential stormwater management service that can proactively mitigate the risk of floods by reducing peak flows. The project will reduce the number of residents without essential services and it is expected to save over $6 for every $1 invested in long-term savings on recovery and replacement costs. It is also projected to ensure the resilience of 19,335 people across an area of 9 km2 exposed to flooding.

Read the Summary Link to Full Case Study

Understanding and Assessing Impacts

The city worked closely with the TRCA to observe and monitor the changes to Lake Ontario water levels. Their observation showed that currently, Lake Ontario water levels are more than 12 centimetres above those recorded at the same time last year. Record high levels are anticipated again this year meaning that there is an increasing flood and erosion risk facing the Toronto waterfront. Additionally in the spring of 2017, Lake Ontario saw an unprecedented rise in water level, as snowmelt and an exceptionally rainy spring season increased water supply causing lake levels to reached their highest water level ever recorded in over 100 years of tracking levels of Lake Ontario. The effect of this flooding event was felt along the entire length of Toronto’s waterfront, especially Toronto Island Park, resulting in flooding and erosion damage. This was further exacerbated during the April 14-15 ice and windstorm event that same year which worsened the shoreline damage. The damage was most pronounced along the perimeter of waterfront parks, such as Bluffer’s Park, Ashbridges Bay Park, Sunnyside Park, Marie Curtis park and Humber Bay Park East and West.

Identifying Actions

As a result of the damages caused by the extreme weather events, the project identified repairs and resiliency enhancements to shoreline erosion control infrastructure as being the primary action of this project. These repairs stretch from Marie Curtis Park in the west to Bluffer’s Park in the east and includes 11 TRCA erosion control assets within Ashbridges Bay Park, Bluffer’s Park and Humber Bay Park East and West. The City’s proposal also recognized that healthy trees provide an essential stormwater management service that can proactively mitigate the risk of floods. By expanding the City’s newly planted tree program and increasing tree maintenance and natural area restoration, the proposed projects aims to increase the number of healthy trees that provide this service. Native plantings along the shoreline will also provide erosion control, proactively addressing erosion post floods.

Implementation

The project identified a list of sites where repair and resiliency improvements would take place as well as the predicted target years which are listed below:

  • Colonel Samuel Smith Park: 2019
  • Len Ford Park: 2019
  • Marie Curtis Park: 2021-2022
  • LenFord Park: 2019
  • Silver Birch Boathouse: 2022
  • Palace Pier Court: 2021
  • Humber Bay park East: 2021 – 2024
  • Humber Bay Park West: 2023-2025
  • Sunnyside Park: 2021- 2022
  • Toronto Island: 2022-2025
  • Tommy Thompson Park: 2023-2025
  • Cherry Beach: 2023-2025
  • Ashbridges Bay Park: 2021
  • Bluffers Park: 20219-2022

It important to note that these components of this DMAF project, represent only the sites prioritized as most impacted/vulnerable to flooding and windstorm damage. With over 46 kilometres of shoreline, not including the TO Islands, and over 11,000 ha of ravines/open space, there are numerous other site candidates that will require protection and climatic resiliency improvements as funding becomes available.

Outcomes and Monitoring Progress

As of early 2022, approximately 50% of the projects, by value, have been completed.
The focus on added resiliency to mitigate increased predicted lake levels has resulted in shoreline erosion structures being increased by an average increase of 1.1 metres in elevation over existing elevations. Post-construction monitoring, including fisheries where applicable, is incorporated in the project improvement program for a period of three years. All completed resiliency improvements monitoring is carried out by the City of Toronto and the TRCA. Upon completion of the initial three-year monitoring, all shoreline and tree canopy improvements will be included in the regular semi-annual monitoring program carried out as a component of asset condition reporting.

Next Steps

Utilizing monitoring and asset condition (Life Cycle) data collected, it the City of Toronto’s intent to continuously develop and improve shoreline and tree canopy resiliency implementation in additional shoreline and valley lands as funding becomes available. An extensive program of asset condition and life cycle analysis will be carried out by the City’s Parks, Forestry & Recreation Department over the next two years to identify vulnerabilities and evaluate the “Health” of our indoor and outdoor assets. This information will then be utilized to include in our 10 year capital plan and seek further opportunities for partnership funding. The City will be looking for improvements, through lesson learned from materials and construction methods utilized, for the reduction of greenhouse gases through the entire life-cycle of these resiliency improvements to meet the City’s NetZero carbon strategy. The City will also be utilizing a climate lens, combined with an ethical community commitment to prioritize new shoreline projects to provide equitable distribution of recreation and environmental enhancement across the City.

Resources

Link to Full Case Study

Additional Resources:

Using climate change projections enables better adaptation decisions, as it allows you to better understand how the climate may change. To learn how to choose, access, and understand climate data, visit ClimateData.ca’s Learning Zone.
For more information on variables that may be useful in work related to Great Lakes shoreline, visit ClimateData.ca and click “Explore by Variable”. Here you will find pertinent future climate projections related to:

  1. Total precipitation
  2. Maximum 1-day total precipitation
  3. Standardized precipitation evapotranspiration index (3-months)