In the Mediterranean region, water does not arrive gradually, it comes in extremes. Long periods of drought are suddenly interrupted by intense storms that can overwhelm landscapes and infrastructure within hours.
This reality is already shaping cities like Sant Boi de Llobregat, where ephemeral streams (rieras) are struggling to cope with increasing climate pressure. Once functioning as natural water corridors, many of these systems have become sources of flood risk, ecological degradation, and fragmented public space.
As part of the Master’s in Urban Resilience for Sustainability Transitions at UIC Barcelona, we were challenged to respond to this evolving condition through our final Master’s project (2025–2026). Throughout the program, we explored themes such as climate adaptation, nature-based solutions (NbS), ecosystem services, and participatory planning — and this project represents the application of those ideas to a real-world challenge.
Working in collaboration with the Ajuntament de Sant Boi de Llobregat, we set out to explore how these landscapes could be reimagined, not as drainage problems to control, but as opportunities to build resilience through nature-based solutions.
First meeting with the municipality of San Boi and Generalitat of Bacelona representatives
Site Visit in the scope area
Dual Deliverables for Resilience
Our final document is designed as a reference for municipal planners and practitioners, particularly in Sant Boi de Llobregat. It explores alternatives to conventional drainage technology for ephemeral streams, focusing on strategies that slow, retain, and absorb water in upstream areas, reducing pressure on downstream systems.
Our project aimed to rethink how these streams can be managed, shifting away from purely engineered solutions toward more nature-based approaches.
We developed two main outputs:
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A Mediterranean Catalog (Best Practices + NbS)
A decision-support tool compiling bioengineering techniques adapted to Mediterranean conditions. It evaluates each intervention based on practicality and ecosystem services, drawing on real case studies from across Catalonia.
>The first part of this catalog focuses on management practices for rieras, outlining the necessary steps to understand how the stream system functions before any interventions are considered.
The second part is a Nature-based Solutions Catalog for the Mediterranean Peri-urban Context, bringing together a curated set of nature-based strategies adapted to Mediterranean conditions. These were selected based on their suitability for hot, dry climates and their ability to address key challenges such as flood risk, soil instability, biodiversity loss, and water quality.
Rather than presenting isolated solutions, the catalogue is designed as a comparative tool, helping municipalities understand how different interventions perform in terms of ecosystem services, cost, and maintenance.
Some of the key NbS strategies included are:
- Bioswales
- Catchment areas
- Check dams
- Gabions
- Krainer walls
- Riparian buffers
- Step terraces
Krainer Walls
Score card
A Pilot Proposal for Sant Boi
A site-specific application of the catalog to the Can Gavarrot corridor, identifying opportunities for intervention and exploring how these solutions could be implemented on the ground.
Pilot Proposal Plans
Pilot Proposed Solutions
Rather than proposing a single fixed solution, we focused on creating a flexible and transferable framework, allowing other municipalities to adapt these strategies to their own contexts.
The catalog brings together strategies that:
- Improve water flow and reduce flood risk
- Restore ecological functions
- Enhance public access to green spaces
- Are replicable, low cost, and low maintenance
Hydrologic and Topographic Analysis
A key part of the project was developing hydrologic data and visual tools to support Sant Boi’s future flood mitigation work. Much of the existing data relevant to flood modeling is either incomplete or outdated. Our data team therefore focused on helping the municipality by filling existing data gaps.
We developed three main GIS outputs:
- Elevation analysis visualizations
- New watershed and stream layers
- Basic flood models
Hydrologic and Topographic Analysis Maps
Towards more resilient Mediterranean landscapes
Finally, as climate pressures intensify across the Mediterranean, the way we understand and manage water systems must also evolve. Rieras are no longer just residual spaces or infrastructure channels, they are dynamic landscapes with the potential to support resilience, biodiversity, and public life.
Through this project, we explored how nature-based solutions can help shift this perspective, offering strategies that work with natural processes rather than against them. While the Can Gavarrot riera served as our testing ground, the tools and approaches developed aim to be transferable to other municipalities facing similar challenges.
Rather than providing a single solution, this work aims to open up possibilities. It encourages planners, practitioners, and local stakeholders to rethink how these spaces are valued and managed in a changing climate.
We invite you to explore the full report in more detail through this link.
Image credits: All diagrams and visualizations are part of the students’ report “Pathways to Resilience: San Boi de Llobregat” – Cohort 2025/2026