The River Vilaine flows right through the historic city centre of Rennes, where it is enclosed by steep vertical stone walls on all sides. The water was a neglected feature in the city centre and many residents voted for its ecological enhancement.

The City of Rennes local council set out a participative budget program in which citizens were able to vote on their preferred city projects and the floating garden on the river received outstanding citizen support. Through a competitive tendering process, Biomatrix Water was selected to provide the floating ecosystem modules that were assembled to create the riverbank

• 658m2 of floating ecosystem surface, divided over four riverbank sections, make up the largest floating riverbank ever created.
• 268 Biomatrix floating islands modules were used, including 26 High Buoyancy Planters for small trees and shrubs.
• 6200 native marginal aquatic plants were planted on the islands, they are expected to mature within their first growing season.
• Streamlined deflectors, internal structural bracing and dynamic anchoring were incorporated in the system to accommodate the challenging site conditions. Peak water flow velocity exceeds 2 m/s and water levels can fluctuate up to 2.5 meters.
• Service walkways run along the entire length of the riverbank sections for the Gardner’s to access the garden.
• Installation continued over one month and a major flood occurred halfway through the installation, with the ecosystems withstanding the high flow rates without difficulty.