Project Overview

The Broadway Avenue project in downtown Winnipeg represents a transformative step toward combining green infrastructure with traditional streetscape renewal. Completed in two phases — East Broadway in 2023 and West Broadway in 2024 — the initiative married sidewalk and roadway reconstruction with the integration of Silva Cells, a system that supports both trees and stormwater management. By installing more than 2,500 Silva Cells beneath the reconstructed sidewalks, Winnipeg created an underground environment where trees have the soil they need to thrive and, for many of the new plantings, bioretention media for at-source stormwater management.

This dual objective — healthy trees and cleaner water — makes Silva Cells an ideal fit for a high-profile corridor like Broadway. As Urban Forester Martha Barwinsky explained, “Broadway is a real iconic roadway in the downtown area. This whole iconic stretch downtown is really just a full rejuvenation of that whole stretch.” The city’s vision extended beyond simply adding new trees: it was about reimagining how infrastructure can work with natural systems to improve long-term resilience, beauty, and function in one of Winnipeg’s most visible downtown arteries.

Broadway Avenue Objectives

The City of Winnipeg set out to accomplish more than just surface-level improvements with Broadway Avenue’s redevelopment. A key objective was to provide long-term soil volume for trees — something not possible in traditional four-by-four pits — while also integrating green stormwater practices that reduce the burden on the combined sewer system. Approximately 80 new trees were planted, each supported by 30 cubic meters of soil within Silva Cells, ensuring better root development, stormwater filtration, and overall tree viability.

Stormwater Management

One of the most innovative features of the Broadway project is the integration of stormwater into the Silva Cell system. For many of the trees, stormwater runoff from the roadway is directed into the soil via a 150mm perforated pipe, allowing filtered water to irrigate the trees while helping reduce peak flows into Winnipeg’s combined sewer system. Other trees, meanwhile, are supported by an automated irrigation system. This dual approach creates an opportunity to monitor tree health and stormwater outcomes under two different strategies in the coming years.

The system itself works by using Silva Cells as a suspended pavement system that holds lightly compacted soil while bearing the load of the sidewalk and road above. Stormwater is dispersed evenly through the soil volume, where it undergoes natural processes of infiltration, filtration, and storage. The result is improved water quality, reduced flooding risk, and healthier trees. As Barwinsky put it, “Silva Cells provide an opportunity to have trees in impermeable settings, which helps manage stormwater and reduces the urban heat island effect.”

Silva Cells in Winnipeg

Broadway Avenue is not Winnipeg’s first experience with Silva Cells — far from it. With more than 60 projects already incorporating the system across the city, Winnipeg has established itself as a Canadian leader in pairing urban forestry with green infrastructure. From downtown plazas to residential corridors, Silva Cells have repeatedly proven their value in creating healthier trees and managing stormwater in challenging urban settings.

The “Made in Canada” aspect of Silva Cells also carries weight for municipalities nationwide. Manufactured domestically, Silva Cells align with Canada’s mandates to prioritize Canadian-made products while delivering resilient, sustainable results. This means cities like Winnipeg can meet infrastructure and climate objectives while also supporting the national economy. For Canadian municipalities balancing climate goals with local procurement priorities, Silva Cells provide a uniquely strong fit.

Federal Funding

A significant portion of the Broadway Avenue project was made possible through support from the federal Natural Infrastructure Fund. This funding partnership highlights how green infrastructure initiatives like Silva Cells are increasingly recognized as essential investments in climate resilience and urban sustainability. For cities across Canada, the project stands as a model for how to leverage federal programs to bring forward-looking solutions into public works projects.

By demonstrating how Silva Cells contribute directly to stormwater management, urban forestry, and climate resilience, Winnipeg has unlocked a path that other municipalities can follow. Projects that combine hardscape renewal with sustainability outcomes can align closely with federal priorities, making them strong candidates for funding. In this way, Broadway not only improved a key corridor in downtown Winnipeg but also set an example for other cities to lobby for (and secure) federal support for green infrastructure projects.

Tree Health

Early signs from the Broadway Avenue project show that trees planted in Silva Cells are already performing well, even in a corridor with heavy traffic, salt exposure, and downtown heat. The generous soil volumes and uncompacted conditions below ground allow roots to expand naturally, supporting healthier canopies and longer lifespans. This aligns with observations from other Winnipeg projects where Silva Cells have been used.

As Barwinsky explained, “The trees planted in the Silva Cells are doing better than new trees planted in traditional wells. It’s a matter of better soil volume, better soil quality, and better root development. Trees don’t grow well in a four-by-four-foot pit in concrete. Even with de-icing salt spray, trees in Silva Cells are much more robust.” Beyond aesthetics, these healthier trees contribute to reduced urban heat, improved air quality, and climate resilience — benefits that will only compound as the canopy matures along Broadway.