2024 Track 2 Day 2: Paris Tersigni


Effective Strategies for Addressing Massive Erosion and Slope Instability in Riverine Environments: Insights from Successful Projects in the GTA

Wednesday March 27, 2024 | 10:00 to 10:30 a.m. | Hall F


Ravine and valley systems in the Greater Toronto Area (GTA) face severe erosion and slope instability issues, stemming from both anthropogenic and natural factors, such as urbanization and climate change.

In some locations these challenges are massive and pose threats to life and property, demanding immediate mitigation strategies. Riverine environments, given their sensitivity, necessitate innovative solutions that not only provide structural stability but also deliver ecological benefits, such as supporting native plants growth and enhancing aquatic, riparian and terrestrial connections.

We will present and compare two remarkable projects initiated in response to these challenges. The first project, a response to the devastating 2013 storm event in Toronto, addressed a critical slope failure in the Humber River Watershed. This catastrophe resulted in significant property loss and posed long-term risks to over ten homes.

Toronto and Region Conservation Authority (TRCA) undertook emergency works in 2015 to stabilize the 12-meter-high slope. Similarly, in 2008, at a separate location along the Etobicoke Creek, the City of Mississauga stabilized a highly eroded 12-meter-high slope.
Both projects implemented vegetated reinforced soil structures, each with unique layouts and systems tailored to local condition.

One of the main challenges was to minimize the impact on expensive land-sensitive residential properties and floodplain encroachment. This presentation will delve into the technical design aspects, choice of materials, and the long-term ecological advantages of the final solutions.

Additionally, we will provide insights into the current status of these structures, offering valuable lessons and inspiration for future initiatives in riverine environments.


Anna Paris

Anna Paris, Maccaferri Canada Ltd.​

Anna Paris is the Business Development Manager for Hydraulic Applications of Maccaferri North America.

She has 15+ years of experience in national and international projects concerning flood protection, drainage, erosion control, stream restoration and slope stabilization, from design to construction.

She obtained her MSc in Environmental Engineering (Water Resources and Land Protection) at the University of Trento (Italy) and had been a visiting scientist at CSU in Fort Collins, CO working on sediment transport and river hydraulics projects.

Santino Tersigni

Santino Tersigni, Maccaferri Canada Ltd.​​

Santino Tersigni graduated from the University of Toronto with a B.Sc., Bachelor of Science in Biology and has worked in many capacities throughout his career.

In June 2000, he started working with Maccaferri Canada Ltd., and has been there ever since. During his past 20 plus years he has developed a thorough knowledge of retaining wall construction, erosion control solutions and geosynthetics.

Santino has been involved in numerous projects. From small home landscaping features to large development projects. His most current involvement has been with the construction of a 30m to 100ft crusher wall for the Greenstone Mine in Geraldton Ontario and with the development of MacBlock a sloped concrete revetment solution for shorelines.