On the night of Oct. 15, 1954, Hurricane Hazel swept across southern Ontario, depositing more than 200 millimetres of rain and killing 81 people.
The Nottawasaga watershed was not spared from Hurricane Hazel’s destructive path; 18 bridges and dams were damaged or destroyed.
In the days leading up to Hazel’s arrival, southern Ontario had been drenched by days of rain. The first two weeks of October had been the wettest in recent memory, and the soil was saturated. Over the span of those two weeks, flood infrastructure in the province was tested but was still holding up to the near-constant rainfall.
Hurricane Hazel made landfall over the coast of South Carolina on Oct. 14, after battering the Caribbean the previous day. Meteorologists expected the tropical storm to quickly lose momentum and peter out once it made landfall, or follow the eastern coast as other comparable hurricanes had in times past.
Hazel, however, had other plans. Instead of pushing away from land or continuing to track along the east coast of the continent, it continued straight, accelerating north through the Virginias, across Pennsylvania, and straight toward our region.
When it arrived, it collided with another storm that had settled over the province earlier in the day on Oct. 15. While Hazel had depleted herself enough to be downgraded from a hurricane to an extratropical storm by the time it arrived, meeting another low-pressure system acted like fuel on an already raging fire.
Winds picked up as the two storms danced their destructive tango over our region. Temperatures dropped by several degrees and the wind accelerated to more than 120 km/h in several areas. Over the next few hours, more than 200 mm of rain was dropped on an already soggy southern Ontario.
In the Nottawasaga watershed, 350 people were stranded at a service station near the cloverleaf exit of Highway 400 at Cookstown. A 20-foot section of road to the south had washed out completely, leaving travellers with nowhere to go.
Highway 12 from Midland to Orillia was under four feet of water, and one officer noted there were several inches of water covering the ground at the top of the hill on Bayfield Street.
Across southern Ontario, many natural waterways, dams, crossings, and stormwater infrastructure had reached their breaking point around the evening hours of Oct. 15. As bridges collapsed and dams gave way, floodwater derailed trains and swept vehicles into streams. Entire houses were lifted and carried hundreds of metres from their foundations.
By the morning of Oct. 16, Hazel had expelled its energy but left behind the equivalent of more than $1 billion in damage to southern Ontario, impacting the lives of countless residents.
As we approach the 70-year anniversary of this extreme storm event, the stakes have only gotten higher. Our watershed’s population has increased, and so has the amount of developed land that is no longer as effective at infiltrating and slowing water from rainfall or snowmelt events. As a result, the need for flood forecasting and monitoring, as well as robust infrastructure designed to handle these events, has grown.
Since 1960, the Nottawasaga Valley Conservation Authority (NVCA) has been working to improve our watershed’s ability to handle large storm events. Today, the NVCA’s flood forecasting and warning program is responsible for monitoring the capacity of our rivers and streams during storm events, and maintaining critical infrastructure like our dams and dikes that help to control surges in flow and limit the chance for flooding. The NVCA also works with property owners to ensure development is not implemented in areas prone to flooding, erosion or other natural hazards.
The memory of Hazel is a stark reminder of the important role conservation authorities like the NVCA play in helping to keep communities safe from flooding and other natural hazards, and the significance of the work we do to protect the people and places of the Nottawasaga watershed.
Dalia Al-Ali is the manager of engineering services with the Nottawasaga Valley Conservation Authority.
