On June 1, 2017, Saint-Etienne Métropole (France) committed to the implementation of measures to strengthen the circulation of wildlife between the different biodiversity rich green spaces and blue areas in its territory. As such, the city of Saint-Etienne officially signed a new green and blue corridor enhancement plan ('contrat vert et bleu') with 13 partners (including municipalities in the metropolitan area, NGOs and academic institutions) for the period from 2016 to 2020. The plan was renewed following the first territorial contract for biological corridors (2011-2015). The cooperative instrument is a new regulatory tool for the protection of biodiversity in the whole metropolitan area. Its objective is to protect a coherent and functional ecological network consisting of biodiversity reservoirs and ecological corridors. It is made up of biodiversity reservoirs: areas where biodiversity is richest and best represented, and ecological corridors: the movement routes used by fauna and flora that link the biodiversity reservoirs. The plan has 24 actions, which aim to reinforce those already undertaken in the first territorial contract for biological corridors, namely: The protection of spaces (within the framework of the local urban plan, such as large gardens, remarkable trees, working gardens); the network of pedestrian pathways (such as the green loop project around the city, linking the current greenways); the demolition of degraded spaces for the creation of spaces of respiration (e.g. the islet Rondet-Tarentaize); the re-qualification of aging public spaces along structuring axes (transversal between the Opera and the Museum of Art and Industry, the Carnot viaduct); and the integration of vegetation in major urban projects (e.g. steel, 3rd line of tramway, Châteaucreux).