Hurricane Hazel’s Legacy

70 Years Ago, the Storm Transformed Flood Management in the Region

October 3, 2024, Toronto, ON — October 15 marks the 70th anniversary of Hurricane Hazel, a historic storm that significantly impacted Southern Ontario and fundamentally reshaped the region’s approach to flood protection and management.

Hurricane Hazel originated in the Caribbean in early October 1954. The storm’s power, combined with saturated ground from heavy autumn rains, caused widespread ruin in the Toronto region.

Homes and businesses were destroyed, highways washed out, and rivers – notably the Humber – overflowed. The impact was devastating:

• 285 mm of rainfall over 48 hours in the Toronto region
• 81 lives lost in the Greater Toronto Area (GTA), with nearly 1,200 lives lost in total due to the storm’s destruction
• Thousands were displaced
• Most bridges on Toronto’s west side were destroyed or badly damaged
• Over $135 million in damages, equivalent to C$1.3 billion today (CAD)

Hurricane Hazel’s aftermath, 1954. Source: TRCA

Hurricane Hazel served as a catalyst for change, revealing the urgent need for an overhaul of flood management practices. A coordinated approach involving Conservation Authorities (CAs), municipalities, and the provincial government was established to enhance flood prevention and preparedness.

This effort marked a turning point for Ontario conservation authorities such as Toronto and Region Conservation Authority (TRCA), redefining and expanding our roles and responsibilities in flood management.

Hurricane Hazel highlighted the dangers of allowing development in flood plains, leading to a shift in land use planning practices intended to keep vulnerable areas free from new buildings or homes.

In response, regulations were introduced, and updates were made to the Conservation Authorities Act aimed at preventing future tragedies, including stricter zoning laws to restrict development in high-risk areas.

Additionally, flood plain mapping was expanded, making it a crucial tool for land use planning decisions.

Alongside these regulatory measures, the introduction of the Lands Acquisition Program enabled the transfer of private flood plain lands to CAs, reducing liability and facilitating the development of flood protection projects.

This initiative played a crucial role in removing at-risk homes from flood plains and converting these areas into green spaces.

Building on these efforts, key changes were made to strengthen flood management, including the establishment of new flood control structures and a comprehensive rainfall observer network, greatly enhancing flood forecasting and warning systems.

In the years that followed, the construction of dams, reservoirs, and channels became a priority to control flooding, with significant projects completed between 1959 and 1995.

These initiatives significantly improved flood resiliency in the Toronto region, positioning it to better protect communities from the growing threat of extreme weather events.

Today, the legacy of Hurricane Hazel is evident in Ontario’s flood management policies and the ongoing efforts to mitigate flood risks.

While CAs and governmental agencies are working on protecting the GTA from severe flooding events, public awareness is also crucial to disaster preparedness.

TRCA helps enhance public safety through our flood plain mapping and land use planning to limit development in flood-prone areas. To determine if you live in an area prone to riverine flooding, use our Flood Plain Map Viewer.

The public can stay prepared by making an emergency plan, signing up for TRCA flood messages and/or following @TRCA_flood on X, and monitoring water levels by visiting TRCAgauging.ca.

As we commemorate the 70th anniversary of Hurricane Hazel, we honour the memory of those who lost their lives and recognize the progress made in flood management since then. Reflecting on these lessons helps us to be better prepared for the challenges ahead.

DOWNLOAD TRCA’S HURRICANE HAZEL FACTSHEET

Quotes:

“Hurricane Hazel was a pivotal and tragic moment in Toronto’s history that reshaped Ontario’s approach to flood protection and management, driving significant changes in how conservation authorities operate across the Province. Recent extreme weather events, including summer floods in Mississauga and Toronto and other extreme weather events across Canada, are a sobering reminder of the critical importance of ensuring our region is well-prepared for future flood challenges. TRCA will continue to work alongside our government and community partners to build resilient communities, so we will never again have to experience the devastation of an event like Hurricane Hazel in our region.”
— John MacKenzie, CEO, Toronto and Region Conservation Authority (TRCA)

About Toronto and Region Conservation Authority (TRCA)

Since 1957, Toronto and Region Conservation Authority (TRCA), as enabled through the provincial Conservation Authorities Act, has taken action to enhance our region’s natural environment and protect our land, water, and communities from the impacts of flooding and increasingly extreme weather events – Ontario’s leading cause of public emergencies.

As the region’s first line of defence against natural hazards, TRCA maintains vital infrastructure and provides programs and services that promote public health and safety, protecting people and property.

TRCA mobilizes a science-based approach to provide sound policy advice, leveraging its position as a not-for-profit operating in the broader public sector to achieve collective impacts within our communities and across all levels of government.

TRCA’s jurisdiction includes nine watersheds and their Lake Ontario shorelines, spanning six upper-tier and fifteen lower-tier municipalities and representing almost five million people, approximately 10% of Canada’s population.

To learn more about TRCA, visit trca.ca.

Media Contact

Afiya Jilani
Specialist, Communication and Media Relations
Toronto and Region Conservation Authority (TRCA)
afiya.jilani@trca.ca