Port Lands Flood Protection Program

For thousands of years, the Don River has flowed into Lake Ontario through one of the largest freshwater marshes in the Great Lakes region. Home to a diverse array of plant and animal species, this wetland long served as a gathering space for Indigenous peoples, but was radically impacted by industrialization in the 19th century, altering the river and removing its natural resilience.

Beginning in the 1880’s, large sections of the wetland were gradually drained and infilled to support industrial and shipping operations, creating what is now known as the Port Lands. This significantly degraded the natural ecology and disrupted the hydrology, impacting the river's connection to Lake Ontario. Industrial pressures eventually forced the mouth of the Don River into a narrow 60-foot-wide channel that became heavily polluted. In 1954, Hurricane Hazel revealed Toronto's vulnerability to flooding and other climate change related impacts, pushing stormwater management to the forefront of the City’s planning agenda. In 1989, public pressure and increased environmental awareness led to early discussions on re-naturalizing the Don River to remediate the Port Lands.  

Today, 290 hectares of southeastern downtown Toronto, including the Port Lands, are at a significant risk of flooding from the Don River when prolonged or intensive rainfall causes the river to overflow its banks. These risks are compounded by the increasing intensity and frequency of climate change related extreme weather events. The PLFP Project was initiated to mitigate these risks. Once complete, the project will provide flood protection to 174 hectares of vulnerable lands, and transform over 30 hectares of brownfield into a naturalized river valley system, including 13 hectares of new coastal wetland and 4 hectares of terrestrial habitat. 

Reconciliation and reconnection serve as the project’s driving themes: reconnection between the land, river and lake, and reconnection between people and nature. The PLFP Project is therefore a tremendous act of reconciliation — both with the Indigenous peoples involved with the project, and with the land and water that have been so significantly altered by industrialization. This renewed relationship is notable particularly for many residents in the city who have limited access to green space, presenting new opportunities to engage with nature, improve public health, and strengthen communities ties with the revitalized landscape that holds rich cultural and historic significance. 

This project aims to restore the landscape’s natural resilience lost through urbanization by using bioengineering and nature-based systems to restore the river valley and recreate valuable habitat. In doing so, the project will not only establish flood protection, but also help to mitigate effects of urban heating due to global warming by creating microclimates and providing access to cooler natural areas.

Climate projections and data availability, such as revised lake levels and storm intensities, directly informed design decisions. Recognizing that extreme rainfall events associated with the historical 100-year storm return period are becoming more frequent and intense, the design team adopted higher elevation thresholds and higher built-in safety margins or “fail-safe” measures. The project’s boundaries and standards were directly informed by the benchmarks and guidelines provided by the Toronto and Region Conservation (TRCA). 

The eight-year duration of the PLFP Project demanded adaptability to evolving climate information and data. For instance, during the design phase the 100-year lake level was revised twice, particularly after flooding events that occurred in 2019. The uncertainty about the impact of climate change on the water level in the Great Lakes reinforced the need for design measures that are fail-safe and adaptable. The new climate data required redesigning the stormwater systems and infrastructure to meet updated elevation projections where possible. 

To establish long-term flood protection, the average grade of the Port Lands was raised by approximately two meters through an extensive ground improvement strategy. Design decisions also responded to anticipated prolonged inundation from high lake levels by incorporating landscape features that can adapt to variable conditions. For example, flood-resilient materials, such as stone dust paths were used instead of asphalt for lower-lying areas to enhance durability and reinforce long-term functionality under varying water levels. 

The integration of nature-based solutions was central to the project’s strategy and was also informed by climate data and projections. An adaptive planting strategy was adopted to establish ecological flexibility to accommodate changes in species migration patterns expected under warming temperatures. To foster biodiversity recovery and the return of native ecological communities, new landforms and water channels were created for the wetlands in the re-naturalized river corridor. A forested riparian edge was also constructed to moderate water temperatures, provide urban cooling, treat urban runoff, and re-establish critical wildlife habitat.  

Several key actions were identified to revitalize Toronto’s waterfront, address the significant flood risk, and restore the ecosystem. The Port Lands area is located within a designated floodplain, and has been recognized by all levels of government as a priority for flood protection, acknowledging that the revitalization of Toronto’s waterfront is not possible until comprehensive flood protection and mitigation strategies are in place. In 2007, Waterfront Toronto (representing all levels of government) launched an international design competition, awarding Michael Van Valkenburgh Associates (MVVA) for their creative vision of a new naturalized river valley, capable of handling high volumes of stormwater while retaining the historic Keating Channel. 

The Port Lands’ industrial history resulted in unstable, poor and contaminated soils, which presented design and engineering challenges to the project. The PLFPP was therefore conceived to both manage floodwaters, and support long-term ecological restoration, such as demands in water flow and the management of sediment and debris. Design elements respond to both natural and human influences by prioritizing the use of green infrastructure and nature-based solutions, including constructed wetlands, vegetated landforms and naturalized channels, that will continue to strengthen and stabilize over time. 

To enhance climate adaptability and support long-term sustainability, bioengineered techniques using living systems, such as root wads, crib walls, and fiber-encapsulated soil lifts, were used to stabilize the riverbanks. These natural materials and systems were selected intentionally for their ability to adapt and regenerate, offering reduced vulnerability to climate stressors when compared to hard-engineered solutions. 

In addition to naturalizing the river valley, the project identified the need for development of new public spaces,roads, utilities and structures essential for connecting the waterfront to the surrounding communities. To improve access between the surrounding neighborhoods and parks, public realm considerations required a balance of ecological goals with expanding recreation and accessibility needs, including reconnecting bike trails and pedestrian circulation routes, as well as the introduction of new walking trails and public infrastructure. 

Summary of design intentions: 

• Lakefilling around Essroc Quay: ecological features increase habitat value and connectivity (e.g., the creation of shoreline coves to provide habitat for fish) (Completed 2020)
• River valley naturalization: coastal wetlands and meadow in river valley to establish flood protection during major storm events (Completed 2024);
• Don Greenway: secondary outlet of wetland and marshes to increase habitat and support flood overflow (Completed 2024);
• Sediment and debris management: river widening and dredging to enable floodwater passage, and manage sediment, maintain safe water flow, reduce flood risk, and treat stormwater;
• Nature-based recreational and gathering destination: community amenities and river valley trail network to strengthen community identity, and increase access to green space and the waterfront;
• Enabling infrastructure to provide capacity for the new neighbourhood created through flood protection that is resilient, increases infrastructure capacity, and provides green solutions wherever possible.

PLFP comprises 23 interconnected sub-projects, each contributing to the larger vision for the Toronto waterfront. Much of the success of the project can be attributed to the integrated design approach that balanced climate adaptation, ecological restoration, and urban livability throughout planning and construction. 

As part of the project’s mandate, Waterfront Toronto led project delivery. The PLFP Project underscores the value of multidisciplinary collaboration and the integration of human, ecological, and cultural systems. Successfully coordinating 23 interconnected sub-projects required a strong understanding of sequencing and interdependencies, and systems-wide coordination to ensure that each component contributed effectively to the project’s overall goals of resilience, restoration, and sustainable community development. 

A major milestone in the project’s implementation was the opening of Biidaasige Park on Ookwemin Minising in July 2025. As Toronto’s largest park to open in a decade, Biidaasige Park exemplifies the project's successful integration of flood mitigation and public realm enhancements. The park represents an early example of the co-benefits that PLFP will deliver, establishing climate resilience with enhancements to infrastructure and new opportunities for recreation, ecological education, and Indigenous cultural acknowledgement of the land and water. 

Ideas surrounding connectedness and system-wide relationships were central to implementation, and were translated directly into the living systems fostered throughout the project. Working with living systems introduced a complexity of interrelationships across the project (e.g., among the soil, water, and vegetation). The sheer scope and scale required to work with the living materials – 2 million plants, 77,000 shrubs, and 5,000 trees – required careful planning, sourcing and logistics to ensure success. These efforts reinforced the project’s mandate for design excellence, demonstrating how large-scale urban development can harmonize with natural systems to deliver climate resilience and biodiversity recovery. 

Renaturalizing the mouth of the Don River represents an internationally significant undertaking. Its scale, ambition, and holistic approach set a precedent for climate-resilient urban design, ecological restoration, and integrated public space. 

The PLFPP takes an adaptive management approach which is reflected in the Operations and Maintenance Plan that was developed to guide long-term monitoring, stewardship, and responsive maintenance. This plan ensures that management practices can continue to align with evolving environmental conditions. Ongoing monitoring (e.g., ecological monitoring of the fish populations, vegetation, wildlife, and biodiversity), evaluation and maintenance will be jointly managed by the City of Toronto and TRCA. During the design phase, a key focus was to establish low-maintenance resilience by emphasizing healthy soils, strong plant communities and self-sustaining ecological systems. 

In addition to remediating the lands and the ecology, mitigating the flood risks across the Port Lands will protect communities and important public infrastructure from future extreme weather events. This $1.4 billion investment is expected to catalyze billions of dollars in private investment, reducing the financial risks of climate impacts to governments. According to Canada's National Disaster Mitigation Strategy, estimates have indicated that every $1 invested in flood protection avoids $5 in potential damages, underscoring the importance of climate resilience and the strong return on investment. As part of the adaptive management process, climate data and performance targets are revisited regularly. A key lesson emerging from the project is how crucial adaptability is for the successful delivery of large, long-term multi-phase projects. Adaptability in the design process is reflective of the project’s core principles of reconciliation and reconnection for resilience, and is evident in the design decisions, integration, and established ecological systems.

The PLFP Project demonstrates the breadth of landscape architecture, encompassing technical infrastructure, ecological restoration, and urban design. This project adopted a landscape-led highly integrated approach, in which landscape architects not only led the consulting team, but also acted as design integrators. In this role, the lead landscape architects (Michael Van Valkenburgh Associates) served as central coordinators for facilitating the large multi-disciplinary team, and were responsible for design consistency and cohesion across the 23 sub-projects. 

The PLFP Project illustrates how landscape architects can lead comprehensively and showcases the professions' strength in the holistic understanding and integration of both natural and infrastructure design systems. By guiding the complex sequencing of work, the landscape architects involved in this project ensured that the site reflects a unified project rather than a collection of fragments. 

PLFP sets a global precedent in establishing flood protection, climate resilience and biodiversity recovery on post-industrial sites for sustainable urban living. The project stands as a source of pride for Toronto and for Canada, exemplifying what can be achieved when reconnection and reconciliation are the central themes in achieving design innovation, ecological stewardship, and cultural recognition. 

Construction of the project began in December 2017, with most areas opened in the summer of 2025. Final sections are expected to be complete by the summer of 2026. 

Extending the river has created a new island, named Ookwemin Minising (meaning “place of the black cherry trees” in Anishinaabemowin/Ojibwemowin). Following the completion of the PLFPP, focus will shift towards Canada’s first climate-positive mixed-use sustainable development community, which will be located on Ookwemin Minising. In January 2025, all three levels of government committed an additional $975 million ($325M each) to accelerate the development of the new housing, services and the public realm of Ookwemin Minising. 

Waterfront Toronto will continue to play a pivotal role, helping to deliver the sustainable urban design principles that guide the area’s construction. Ookwemin Minising will demonstrate novel technological advancements to achieve net-zero and other sustainable living and development goals, integrating public parks and restored natural habitats with built infrastructure. Once complete, the island will offer homes for approximately 15,000 people, including affordable options, and contribute 15 additional acres of parkland. 

The next phase of the larger waterfront revitalization plan will extend the program to the Eastern Waterfront with the Quayside development, providing additional housing for 100,000 people and creating over 100,000 skilled trades jobs. Together with Ookwemin Minising, these developments are projected to contribute $13.2 billion to the Canadian economy.

• Waterfront Toronto - Don Mouth Naturalization and Port Lands Flood Protection Project
• THE PORT LANDS - What is the Port Lands Flood Protection Project?
• THE PORT LANDS - What are we building?
• WSP - Port Lands Flood Protection Project
• Michael Van Valkenburgh Associates Inc. - Port Lands Flood Protection Project
• TRCA - Don Mouth Naturalization and Port Lands Flood Protection Project
• EllisDon - Port Lands Flood Protection & Enabling Infrastructure
• City of Toronto (July, 2025) - Largest Park in a Generation Opens on City of Toronto’s New Island through Transformative Port Lands Flood Protection Project News Release
• Waterfront Toronto - A New Waterfront City is Coming into View Video