Integration of infrastructures with their immediate environment-OASIS, HIDROTAL and RECOTAL

Embankment revegetation study. Spain. Embankment revegetation study. Spain.

In this context, OHL Concesiones has undertaken a number of initiatives with a view to improving the integration of the infrastructures with their natural surroundings, as, for example, in the following projects:


  • A scientific methodology was developed that enables the objective assessment of the landscape in order to establish comparisons and measure impacts
  • An investigation was made of the causes of vehicle-wildlife collisions for the purpose of reducing them and of the management of the vegetation surrounding the road
  • Further knowledge was obtained about the revegetation of embankments and the seed bank of the soil removed in the construction process to reduce costs and improve the effectiveness of this project stage. On the basis of this investigation, guidelines were established geared to better revegetation in the Mediterranean environments


The earthworks associated with the construction of transportation infrastructures generate new spaces at the same time as they disturb and fragment the original mosaic of ecosystems.

In response to the challenges posed by these new spaces, we developed the HIDROTAL project between 2003 and 2006, with the support of the concession company Autopista Eje Aeropuerto.  The aim of the project was the development of criteria and methods for evaluating the success of the restoration of the embankments created along the new infrastructures by means of hydroseeding.

The results showed that the embankments create an environment different from any other natural ecosystem. These microclimatic, edaphic and biological differences determine that the contribution of the hydroseeding plays a secondary role in comparison to the propagation of local plant species.

With the conclusions obtained in HIDROTAL, the Group initiated the RECOTAL project, carried out in 2007-2008, the objective of which was the characterization of the ecological processes in the immediate environment of the infrastructures.

With the results obtained in the two projects, it can be concluded that indiscriminate application of hydroseeding for the revegetation of embankments of linear land transportation infrastructures is not warranted.

Therefore, a conceptual change has come about for addressing this environmental problem: instead of acting on the objects (hydroseedings and plantations), we focus on the ecological processes.