Following Water Through a Mediterranean Landscape 

Learning lessons in the footsteps of flooding in eastern Spain.

On 26 March 2026, a small group of researchers, practitioners, and communicators moved slowly across the Sierra de Chiva, stopping at points that, at first glance, seemed unremarkable: a forested slope, a dry ravine, a patch of dense shrubland. Yet each of these places formed part of a system that, just months earlier, had carried destructive flows from the mountains to the plains of Valencia. 

The watershed field visit, co-organised by Centre per a la Investigació i l’Experimentació Forestal (CIEF) – CIEF, and the European Forest Institute (EFI), as part of the Mediterranean Network Forum, was conceived less as a technical briefing than as a way of reading the territory. By following the path of water from the upper basin of the Rambla de Poyo down to the Albufera lagoon, it revealed how landscapes structure risk (and resilience) – and how that structure is changing. 

What emerges along this trajectory is not a single event, but a sequence of relationships: between vegetation and soil, land use and hydrology, upstream decisions and downstream consequences. 

A system that regulates (until it doesn’t) 

The Sierra de Chiva forms part of a relatively inconspicuous hydrological system. Unlike the Turia or the Júcar, it is not defined by a permanent river, but by a network of ephemeral watercourses that activate during periods of intense rainfall. These channels, often dry for much of the year, connect the mountainous terrain to the densely populated areas of Horta Sud and, ultimately, to the Albufera. 

This type of watershed depends heavily on the condition of the landscape through which water moves. Vegetation cover, soil structure, and land management practices all influence how rainfall is absorbed, retained, or released. When these elements are functioning in balance, they distribute water across time and space, reducing peak flows, and limiting downstream impacts. 

As Xavier García Martí, forest engineer at Plataforma para el Estudio y Conservación de la Sierra de Chiva, explained during the visit, “this watershed area and its regulation services are fundamental in mitigating major floods.” The emphasis here is not on the exceptional nature of extreme events, but on the everyday capacity of the system to regulate them. 

That capacity, however, is not fixed. 

The 2024 DANA: A system under stress 

In October 2024, approximately 600 millimetres of torrential rain fell in less than half a day across parts of this basin. The intensity of the event was exceptional, but its consequences were shaped by conditions that had been built over decades. 

Water moved rapidly from the upper slopes, carrying sediment, vegetation, and debris through the network of ravines. By the time it reached the lower basin, the combined force of these flows overwhelmed urban areas that had expanded into historically flood-prone zones. The result was catastrophic: more than 200 fatalities, widespread damage, and a landscape visibly altered by the passage of water. 

Standing in the upper basin months later, the physical traces of the DANA remain – widened channels, exposed soil, disrupted vegetation. Yet the event cannot be understood solely through these immediate impacts. As one participant noted during the visit, the flood “did not start with the storm; it started with the way the landscape has been transformed over time.” 

This distinction is critical. The DANA was not only a climatic event; it was also the expression of a system under stress. 

From managed landscape to fragmented territory 

The Sierra de Chiva still carries evidence of a more integrated relationship between land use and ecological function. Terraces built to prevent erosion are visible along the slopes, remnants of agricultural systems that combined production with water management. Crops such as almonds, olives, vines, and carob once formed a mosaic landscape, supported by grazing practices that helped regulate vegetation density. 

Over the past half-century, this system has gradually been dismantled. Rural abandonment, shifts in economic activity, and the decline of traditional practices have altered both the structure and function of the landscape. In many areas, dense pine regrowth following repeated fire events – including a significant fire in 2003 – has led to more homogeneous vegetation, increasing both fire risk and the speed at which water can move across the surface. 

At the same time, the lower parts of the basin have experienced sustained urban and industrial expansion. Watercourses have been diverted or constrained, and development has taken place in areas historically shaped by periodic flooding. These changes have effectively reduced the space available for water to spread and dissipate energy. 

The cumulative effect is a system where natural regulation is weakened, and exposure is increased. 

Forests as functional infrastructure 

One of the central insights of the field visit is the need to reconsider how landscapes are valued within risk management frameworks. Forests and shrublands are often discussed in terms of biodiversity or conservation, but their hydrological role is equally significant. 

“The regulatory services provided by these forests and Mediterranean shrublands are of enormous importance to the densely populated areas of the Valencian plain,” García Martí explains. These services include reducing runoff, stabilising soil, and facilitating aquifer recharge — processes that are essential not only for ecosystem health, but also for agriculture and urban resilience. 

From this perspective, public forests such as those in the Sierra de Chiva can be understood as part of a broader system of infrastructure. Unlike engineered solutions, their effectiveness depends on long-term management and ecological integrity. Yet their contribution to reducing risk is no less real. 

As one of the CIEF representatives noted during the visit, “if we neglect these systems, we are effectively reducing our capacity to manage water before it reaches the city.” 

Restoring function at the end of the basin 

The downstream section of the visit, at Tancat de la Pipa, provides a counterpoint to the processes observed in the upper basin. Located at the edge of the Albufera, this site demonstrates how ecological restoration can reintroduce functions that have been lost elsewhere in the system. 

Once an intensive rice field, Tancat de la Pipa has been transformed into a wetland composed of lagoons and marshes. Managed through a model of custodia del territorio by Acció Ecologista-Agró and SEO/BirdLife, it serves multiple roles simultaneously. 

Water entering the site is slowed, allowing sediments to settle and pollutants to be filtered through natural processes. The wetland also acts as a buffer during periods of high flow, reducing pressure on downstream areas. In parallel, it supports a wide range of species, contributing to biodiversity within the Albufera system. 

What distinguishes this site is not only its ecological function, but the governance model that sustains it. The collaboration between civil society organisations and public authorities enables long-term stewardship, aligning conservation objectives with water management needs.

As one of the organisers from AGRÓ explained, “this is not about recreating nature as it was, but about restoring the functions that the system needs today.” 

Connecting the system 

Taken together, the Sierra de Chiva and Tancat de la Pipa illustrate the extent to which flood risk is distributed across space and time. The same water that accelerates in the upper basin is eventually absorbed and filtered in the lower reaches, provided that the necessary ecological conditions are in place. 

From mountains to wetlands, this watershed reveals two distinct but interconnected trajectories: one in which degradation amplifies risk, and another in which restoration contributes to resilience. 

The challenge lies in aligning these trajectories. 

This requires moving beyond fragmented approaches that treat upstream and downstream areas separately, or that prioritise short-term solutions over long-term system functioning. It also requires integrating ecological knowledge into planning processes that have historically overlooked these dynamics. 

Beyond Event-Based thinking 

The field visit highlighted a broader issue in how environmental risks are framed. Extreme events tend to be analysed in isolation, with attention focused on immediate causes and impacts. Yet the conditions that shape these events – land use, vegetation patterns, governance decisions – evolve over much longer timescales. 

Understanding this requires a shift in perspective. 

Floods are not only the result of extreme rainfall. They are also the outcome of accumulated changes in how landscapes are managed and inhabited. Addressing them therefore involves not only responding to events, but rethinking the systems within which those events occur. 

In the Sierra de Chiva watershed, that system remains visible – and, to a certain extent, still functional. Its future will depend on whether that functionality is recognised, maintained, and restored where necessary. 

The implications extend well beyond this particular basin. Across the Mediterranean, similar dynamics are unfolding, linking ecological processes to social and economic outcomes in ways that are often poorly understood. 

Making those connections visible is a first step. Acting on them is the next. 

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