In Dehesa de San Francisco, the naturalisation of the reservoir has been carried out with the aim of improving local biodiversity and protecting the land from erosion.
The reservoir, initially designed for water storage for fire prevention purposes, was located in an area with low scrub density and poor natural regeneration of Quercus. The shrub vegetation was dominated by species such as Cistus crispus, Cistus monspeliensis and Genista hirsuta, and the downstream drainage channel showed clear signs of erosion.
To reverse this situation, various actions have been implemented in two phases:
Phase 1: Infrastructure adaptation
- Cleaning of the reservoir and its catchment area.
- Installation of a submerged fence dividing the flood zone into two sectors: one with restricted access to livestock and the other with free access.
- Placement of 4 m³ of gabions in the spillway and stabilisation of the terrain to prevent erosion.
Phase 2: Stratified reforestation according to the moisture gradient
- Flood zone: planting of aquatic herbaceous plants of 8 different species and specimens of Juncus spp.
- Non-flood zone: planting of Nerium oleander (oleander), Flueggea tinctoria and Rosa canina
- Complement: planting of Fraxinus angustifolia (narrow-leaved ash) in pre-existing exclusion cages near the reservoir
Measures to reinforce fauna
Insect hotels and specific shelters for amphibians and reptiles have been installed, encouraging the presence and reproduction of local fauna.
During the two years following the intervention, maintenance and replacement of species with low survival rates has been carried out, thus ensuring the success of the restoration.
This action contributes to protecting a key ecosystem in the Dehesa de San Francisco, combining erosion prevention, vegetation restoration and the promotion of local biodiversity.
