Casey Sack

Knysna is sinking.

By 2100, Thesen Island, a residential marina located in the heart of the Knysna Estuary, will be underwater for at least 12 hours per day.

Buoyanc[it]y confronts the threat of rising sea levels for the coastal town, and the need for a flood-proof architectural response.

The project envisions a floating ecological research centre and fibreglass factory, as an opportunity for the continuation of human activity in the area, once the landscape begins to drown. The site of intervention sits at the entrance to the island, where a bird reserve and 7 human households exist today – all destined for inundation.

The proposed floating structures rise and fall with the changing tides, and are replacement habitats for all species. With inherent flexibility in design, the intervention transforms alongside changing human and environmental needs. This flexibility questions the architectural convention of permanence.
This adaptability is inspired by the ability of natural organisms to respond to their environments. The project seeks to restore damaged ecology through biomimicry, with nature as the architect, and the building as an evolving organism. Estuaries are natural flood barriers. Thus, the building mimics the protective qualities of the estuary, in order to rebuild the shoreline, and to replace drowning habitats.

Oysters are the hero of the intervention. A living, growing oyster reef lines the edge of the site. As a breakwater, it protects the land from erosion and surging waves. Over time, shells break down, turning the oysters into sand, which restores the depleting ground. Furthermore, the reef functions as a habitat for birds.

Critically, after their death, the shells are processed to make fibreglass to construct additional floating buildings. These buildings become the site of implantation of more oysters. Thus, the oysters and architecture form an ecosystem – a cyclical, mutualistic relationship between man and nature.