Starting this month, Toronto begins removing 847 trees as part of a flood mitigation project aimed at protecting the flood-prone Rockcliffe-Smythe neighbourhood. Residents and community advocates, however, urge a halt, arguing the plan to widen Black Creek and replace Jane Street and Scarlett Road bridges lacks scientific validity and could exacerbate flooding.
Residents Demand Upstream Fixes
“Fixing the bridges over here without knowing how to fix the problem upstream is like putting the cart ahead of the horses,” states Antia Gonzalez Ben, a member of the Black Creek Flood Coalition (BCFC). Gonzalez Ben, Sarah McVie, and fellow BCFC members highlight that nearly 2,500 residents suffer repeated floods and sewage backups, incurring thousands in damages each time.
The city and Toronto and Region Conservation Authority (TRCA) acknowledged the issue through a 2013 environmental assessment that shaped the current plan. Yet, the strategy overlooks the primary concern: a 12-metre upstream channel in Black Creek from Weston Road to Hilldale Road, home to most affected residents, notes McVie.
McVie points to flaws in the project’s computer model, identified by independent water resources engineer Tim Mereu. The TRCA confirmed modeling software issues during a recent meeting with McVie, Mereu, and others, though the project now falls under city oversight.
Community Rally Against the Plan
Residents rallied at Smythe Park last weekend, where tree removal looms, calling for plan revisions before work proceeds. The three-phase project labels Rockcliffe-Smythe among Toronto’s most flood-vulnerable areas, with first-phase construction slated for late summer or early fall.
McVie advocates for a redesigned approach and a city-appointed coordinator. “Every house needs an emergency preparedness kit and we need a coordinator … someone managing the situation,” she says.
City Stands Firm on Modeling
City spokesperson Krystal Carter affirms commitment to the environmental assessment. “Modelling results are consistent with the environmental assessment,” she states in a recent email. “Work to increase the span of the Jane Street bridge will begin first, as it provides flood risk relief to the greatest number of properties, as identified in the Environmental Assessment.”
Carter adds that widening Black Creek and replacing the bridges will significantly reduce flood risks. The city pledges ongoing resident engagement.
Engineer’s Critique Reveals Model Gaps
Engineer Tim Mereu scrutinized the project after learning of local flooding claims. He found the model neglects friction and water speed changes, inflating flow rates unrealistically.
“Both the physical model I created and reflecting on the error of friction … it is very clear that this little section of channel will continue to flood and therefore the 200 homes will continue to be at risk of flooding,” Mereu explains. His physical model replicates the project, underscoring persistent upstream risks.
Mereu traces errors to overreliance on software without physics fundamentals. “A model is just a tool to come up with an answer. There’s physics involved, and the solution has to adhere to the laws of physics,” he asserts.
In December, the city issued terms for an engineering consultant, including a clause to verify calculations. A January TRCA meeting admitted a model “anomaly,” per Mereu.
TRCA Addresses Concerns
TRCA’s Sameer Dhalla, director of engineering services, recognizes raised technical concerns and commits to resolution in the design phase. Additional resident meetings follow the consultant’s review, as the project advances to construction, prioritizing bridge upgrades.
