Rewilding Gredos

Water

Water harvesting brings together a range of techniques designed to slow and redistribute runoff, allowing part of the rainwater or snowmelt to infiltrate gradually into the ground. Instead of letting it flow rapidly down streams and slopes, the water is guided through small channels, ditches, or permeable structures towards areas where it can soak into the soil. Water “sown” during the wet months then moves slowly through the subsurface and may reappear later in springs, fountains, and watercourses. Traditional systems such as the acequias de careo of Sierra Nevada have used this principle for more than a thousand years to recharge aquifers and extend water availability through the dry season. A recent study on the nearby slopes of La Vera highlights precisely the importance of mountain groundwater in sustaining rivers and supplying the outer areas of the valley.

Applied to mountain savanna landscapes, hydrological rewilding seeks to restore the natural processes that help slow, infiltrate, and store water across the landscape. Vegetation, roots, burrowing animals, organic matter, wetlands, and the natural dynamics of streams and gullies can all help retain a greater share of rainfall in the soil and allow it to move gradually toward springs and aquifers, rather than rapidly draining from the slopes. This could help preserve soil moisture for longer, sustain grasslands, ponds, and small wetlands, and increase vegetation resilience to increasingly severe droughts. Mountains also play an essential role in groundwater recharge, as they receive more precipitation and feed springs and streamflows that support ecosystems, communities, and farms further downstream. For this reason, we want to work with specialists and public authorities to study how restoring ecological processes and key species could strengthen this natural function of the landscape. The aim would not be to artificially reshape watercourses, but to help the landscape recover its own capacity to retain, redistribute, and infiltrate water, while evaluating the effects through hydrological and scientific monitoring.