Weaving the Islands

Toronto Islands, Toronto, ON. 2021.

In Collaboration with Stefan Herda Awarded: Professor Jeffery A. Stinson Graduate Student Endowment Fund

Existing edge condition of Gibraltar Point.

The Toronto Island shoreline is extremely vulnerable to flooding and erosion. Instead of looking out from the edge we decided to look inward, holding the islands together with a softer process-based approach. We wove resilient living systems, in the form of planted bioengineering strategies, into the mosaic of the island in the hopes of creating a connection to the land.

The section shows a moment in time, extracted from a wave height diagram within the Baird report. This is a severe storm modelled with a 3m 8s storm waves and has obviously been prolonged as you can see from the flooding.

The fish have taken shelter and the vegetation is intact, whereas vegetation in the “open water” has been ripped up and sediment is swirling.

How and where could we best incorporate the existing materials, processes and plant communities of the island to help mitigate erosion and flooding? We analyzed 53 existing edge conditions on the islands and created a vulnerability index, correlating bioengineering strategies to each score. 'Wave Height', 'Flooding', 'Open Area' and 'Soil Erodibility' were some of the factors considered.

Along the inner harbour of Ward’s island a living berm planted with salix shrub species marks the passage of water from sky to roots through concrete water columns. This is part of a system of dry wells sending inverted colums of roots down into the earth, creating an unseen network of support, a true living berm.

Time is applied to the system, layering stewardship, water and growth. These interactions are revealed through the redirection of water, creating nodes of growth and human notice, marking the passage of water from the sky to the earth.

Stewardship of this living berm is an important aspect of the system. Coppicing, planting, harvesting and cutting will take place at certain times of the year. Studies have shown that diversity in root architecture is important. As the roots twist and mat around the dry well’s they form columns creating an unseen network of support, a true living berm.

The grooves and notches of these water markers were investigated through a conceptual concrete model. Here we see the path of water beginning as rain falling during a storm event, some of the rain is intercepted by the top of the column while the rest falls upon the path.

Proposed edge condition of Ward’s Elbow.

The berm itself is constructed from a compacted clay core on the landward side to prevent water seepage. Both sides of the berm are sloped and built up with structural soil.

The landward side has a vegetated crib wall system whereas the lakeward side is unsupported at a slope of 30% which is the typical angle of repose of soil.

Bending is what a willow wants to do, it is flexible, well rooted, letting water wash over, thriving despite environmental pressure. We must aspire to be like the willow, drawing strength from within, looking down toward the humble root to weave the islands back together.