This December saw the start of the second and last phase of planting in the “El Estajao” meander, in Alfaro, La Rioja, which will complete the morphological adaptation carried out by the Ebro Hydrographic Confederation within the framework of the Ebro Resilience Strategy for reduce the risk of flooding and restore the meander to an environmentally sound state.. A total of 21,100 specimens of native riparian species will be planted.
This work completes the work that, with an investment of over 2 million euros, has recovered 23 hectares of meander as a fluvial space, achieving a stretch that is more adapted and resilient to floods caused by the Ebro River floods.
The planting works that had a first phase last February will be completed, in both cases, at the most favorable time for the rooting of the vegetation with plant species suitable to the ecological conditions of the area and, of course, to the conditions of the river itself, which in early December exceeded 900 m above sea level.3/s in this section, a flow that occupied the recovered meander.
During this recent episode, the first plantations planted 10 months ago have fulfilled their function of retaining drags, something typical of riparian vegetation and which responds to the lines of action of the Ebro Resilience Strategy, with solutions based on nature and, above all, betting on the recovery of ecosystems as one of the tools against floods.
The first phase of the project sought to achieve this preventive and protective function by planting trees in the 25 meters closest to the new embankment.
Techniques and species
The plantations carried out in “El Estajao”, and in general all those in areas recovered by the Ebro Resilience Strategy and the LIFE Ebro Resilience P1 Project, seek to generate riparian groves in the most natural way possible. For this reason, the techniques used are the “vegetation coup” and “staggered” planting techniques, which mimic the natural growth of vegetation on the riverbanks.
The selected species are ash, willow, tamarisk, white poplar and black poplar, along with accompanying shrub species.
The more than 100 elm trees donated and produced by the Ministry for Ecological Transition and Demographic Challenge, which are resistant to the disease graphiosis, stand out.
Morphological adequacy
The works, within the framework of the Ebro Resilience Strategy, had a completion period of 24 months and are aimed at improving the morphological conditions of the riverbed .
The works included in this project are summarized as follows:
- Removal of 450 meters ofthe current defense, which runs along the perimeter of the meander, and construction of a new one set back at a maximum distance of 500 meters, with a length of 570 meters.
- Clearing of productive poplar trees in an area of 21 ha.
- Construction of a krainer type wall, at the junction of the new defense with the current one, with a length of 100 meters anda width of 5 meters.
- Recovery of river space: 23 ha of land will be recovered as river space, of which 21 ha will be restored with the planting of 21,100 specimens of riparian species typical of the banks of the Ebro.
This action is part of the “Combined section of actions”, between Alfaro and Castejón (Navarra), which includes different proposals to reduce the effects of flooding in the area of confluence of the Ebro and Aragón rivers: the “La Nava“, “La Roza” and “El Estajao” and the “Soto de Tamarigal”, all in Alfaro; the “El Ortigoso” site in Milagro and the meander of “El Señorío”, in Castejón, both in Navarra.