The river Llobregat is a backbone of the metropolitan territory and its area has been strategic for the implementation of large infrastructures, for economic development and for the transformation of nearby urban centres.
However, it is also an area with great potential from an ecological and social point of view. Aspects to be highlighted are its contribution to the preservation and improvement of biodiversity and ecological connectivity. It is also important to mention its proximity to a large part of the metropolitan population, turning the river into a new type of local public and natural space.
Thus, the Llobregat is one of the main axes of the metropolitan green infrastructure (GI). Its recovery is in line with the European Union’s own definition of this infrastructure: “GI: a strategically planned network of natural and semi-natural areas with other environmental features designed and managed to deliver a wide range of ecosystem services. It incorporates green spaces (or blue if aquatic ecosystems are concerned) and other physical features in terrestrial (including coastal) and marine areas. On land, GI is present in rural and urban settings. […] GI solutions are particularly important in urban environments in which more than 60% of the EU population lives”. Green infrastructure is a strategic line of European environmental policy.
In this context, additional challenges are also pursued, such as the balance between the preservation of ecological values and the provision of other ecosystem services, especially those related to the cultural and social values of these spaces. Another relevant factor is the state of this ecosystem, since we are in an environment in which the historical biological and abiotic characteristics have been profoundly and irreversibly modified. A key aspect of this phenomenon would be the irreversibility of certain thresholds that prevent restoration to a historical state.
The concern of the Barcelona Metropolitan Area (AMB) for the quality of the landscape of the final stretch of the Llobregat goes back a few decades. In recent years, these efforts have been channelled through an investment programme of actions in natural and urban landscapes (known as the PSG), carried out with the economic collaboration of the municipalities with river sections, with investments amounting to nearly 40 million euros committed in the 2015-2023 period.
It is a privileged metropolitan natural space, heavily altered and boxed in by multiple transport and service infrastructures, with great ecological and social potential. In this context, the aim is to reinforce the role of the river and its tributaries as ecological corridors, as well as the ecosystem services they provide, especially cultural and social services and those supporting biodiversity. In this way, the approach is particularly sensitive to social and ecological values and landscape dynamics.
The three most basic elements of the landscaping of the final stretch of the Llobregat are water, vegetation and roads. These elements form a vital landscape in an intensely humanised space. Thanks to them, the river area still conserves great potential in relation to social use, the improvement and maintenance of biodiversity and connectivity with other areas of the metropolitan territory that allow the ecological values of the space to be maintained. And given the characteristics described above, they have to coexist with others generated artificially such as highways and railway lines.
The concept of river is completely linked to that of the water flowing through it, marking a direction, a course and facilitating the perception of movement. But it is not only important for the perception of the landscape, as it also serves to recharge the aquifer of the Llobregat Delta through infiltration (places that deserve special treatment and protection) and to achieve a natural maintenance of the riparian forest.
Regarding the riverside vegetation, the trees are the scenery that delimits the river landscape, defining its shapes, a cool atmosphere, a sound and its own colour. In addition, they interact with the riverside paths, hinting at their route.
The paths allow for social use and enjoyment of the entire river area. Correct interconnection is essential in order to position places of passage and their extension throughout the territory. This includes the existence of floodable fords connecting these riverside roads on both banks, since a connection by road bridges at a height much higher than the roads is insufficient.
With all this, you can enjoy the moving water, the vegetation and the existing fauna, which is becoming more and more diverse, with an adequate network of trails. In short, a balance is sought between social use and an improvement of the landscape and environmental values that guarantee proper biodiversity.