The world’s largest floating riverbank is built in Rennes, France
July 10, 2018
Location: River Vilaine, Rennes
Client: Rennes City Council
Objective: Ecological Enhancement
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.
As a result of this project, the once stark and relatively lifeless Vilaine river at the heart of Rennes city centre is coming to life again, helping to make Rennes one of Europe’s pioneering Living Water Cities.