Identifying main challenges for a broader use of river bio-engineering for bank protection in urban context

Abstract

Soil bioengineering is a technique based on the use of living plants and their mechanical or biological properties to ensure certain functions). In urban areas, it is an alternative to civil engineering for bank stabilization, flood protection and erosion control. Although providing many ecological and social services, their use is still marginal in riverbank development, particularly in urban areas. In this article, we aim to understand the brakes and levers to a wider use of soil bioengineering in cities. We focus on the perceptions of practitioners (with semi-directive interviews) and users (with a photo-questionnaire survey). Our results show that practitioners consider that using soil bioengineering techniques requires a paradigm shift, through a redefinition of performance, greater acceptance and sharing of risk, and a change in professional posture. Users, for their part, are fairly positive about these techniques, particularly because of their aesthetic value, but they do express certain reservations, linked to the recreational value of the banks and to the feeling of vulnerability in the event of flooding. The first type of reluctance can be partly overcome by providing physical and visual access to the river when the structures are installed, and by regularly maintaining the vegetation. The second involves further work on the risks associated with the destabilization of these structures, both in physical terms and in terms of their social acceptance.