Donostia City Council rewilds a stretch of the River Errekatxulo as part of the LIFE IP Urban Klima 2050 project
27/03/2023
One of the objectives of the LIFE IP Urban Klima 2050 programme is to prevent future river flooding by implementing nature-based solutions on various rivers. This action on the River Errekatxulo is just one of many other carried out by San Sebastian City Council.
This stream is located in the Belartza industrial estate. Due to the construction requirements of the industrial park, the entire stream was channelled away from its natural course, giving rise to a straight stream made of concrete, without nooks and crannies for wildlife to live in, or vegetation on the banks that would give rise to a riparian forest.
All of this has an indirect effect by diminishing the capacity of smaller watercourses to absorb the amount of energy and extra water that reaches them during heavy rainfall events. The sum of all these reductions in the absorption capacity across the entire minor river network has a very negative impact, among other effects, on the flooding events that cause so much economic damage downstream, in the main river network (Igara, Martutene...), which are the subject of this LIFE project.
The River Errekatxulo is made up of several stretches in which action will be taken in different phases with the clear goal of rewilding the majority of them.
On this occasion, restoration work was carried out on the northern valley floor of the aforementioned industrial estate. The solution adopted is intended to achieve a physical rewilding of the stream, making the old straight channel more winding and replacing the concrete structure with natural materials in such a way as to restore the ecological potential of the stream, as far as possible, and to allow the dynamics of the environment, vegetation and fauna to gradually create a higher quality river ecosystem than the current one.
These actions, and those that will continue in the future, will improve urban biodiversity, which provides so many goods and services to citizens and which they use directly and indirectly (stabilisation against natural events such as floods and droughts, air and water purification, aesthetic and cultural benefits). They will also improve connectivity, the restoration of which will mean the recovery of contact areas that have been lost due to habitat fragmentation; therefore, the restoration of rivers and riverbanks will encourage the role of river systems as ecological corridors, by facilitating the movement and/or refuge of wildlife in fragmented landscapes.
We know that the green spaces with the greatest urban biodiversity are those located near the hydrological network and those in the transition zones towards peri-urban areas, so the restoration of the River Errekatxulo is aimed at creating an interconnected network of green spaces that conserve the functions and values of natural ecosystems, and provide associated benefits to the population.
Furthermore, this type of action is expected to set an example, so that small rivers will be taken into account in future actions when designing new urban developments (residential, industrial or commercial) and artificial situations such as the one involving the Errekatxulo will not be created and then have to be reversed later on.
