Nature-Based Solutions Versus Flood-Control Engineering: Preventing Ecological Degradation in a Peri-Urban Mediterranean Stream

Structural flood-control engineering can create negative impacts and societal conflict, yet few studies critically examine such projects while explicitly evaluating Nature-based Solutions (NbS) as alternative applications. This article presents a real Mediterranean case in which a large structural flood-control project was halted following ecological and legal scrutiny, creating an opportunity to reconsider flood management through an NbS framework. The study focuses on the Erasinos stream (Attica, Greece), where a government- and EU-funded flood-control project proposed extensive river channelization, flood-retention dams and other “hard” measures within and adjacent to a protected Natura 2000 area. Rather than proposing a detailed engineering redesign, our study compares two contrasting planning paradigms: the original engineering scheme, initiated in 2021, and a conceptual Nature-based Solutions (NbS) framework based on Natural Flood Management (NFM) and ecological restoration initiatives. The proposed NbS framework would substantially reduce structural river-training works while emphasizing distributed flood-water retention, restoration of river connectivity, floodplain reconnection and biodiversity enhancement. Such an approach has the potential to reduce flood risk while simultaneously enhancing biodiversity, cultural and protected-area values. The Erasinos case demonstrates that integrating ecological restoration, NbS and flood-risk management can shift peri-urban river planning away from rigid structural control toward a nature-positive management paradigm for Mediterranean catchments.