Greening Flood Protection—An Interactive Knowledge Arrangement Perspective

Abstract

In flood protection, the dominant paradigm of 'building hard structures' is being challenged by approaches that integrate ecosystem dynamics and are 'naturebased'. Knowledge development and policy ambitions on greening flood protection (GFP) are rapidly growing, but a deficit remains in actual full-scale implementation. Knowledge is a key barrier for implementation. To analyse conditions for the implementation of GFP, a knowledge-arrangement perspective is developed. The knowledge-arrangement perspective is applied on a case study of successful implementation of GFP in the Netherlands, the pilot Sand Engine Delfland, a large-scale (21.5 Mm 3 ) sand nourishment project. This project confirms that an integrated knowledge arrangement enables GFP as it allows for multifunctionality. Effectiveness of the integrated arrangement in this project is explained by its 'flexible' nature providing ample design space. This was possible because core values in flood protection and nature were not part of the integrated arrangement. More generally the case study demonstrates the difficulties of implementing GFP in existing mainstream flood protection routines. These are not (yet) geared to incorporate uncertainty, dynamics and multifunctionality, characteristics associated with GFP. The Sand Engine project can be regarded as a 'field laboratory' of physical and institutional learning and an innovation for mainstream flood protection.

Trends in flood risk management in deltas around the world: Are we going ‘soft’?

“…several 'Building with Nature' pilot projects are being implemented to learn how coastal flood protection measures can be developed that benefit from, and are supported by, existing coastal ecosystem dynamics (De Vriend & Van Koningsveld, 2012). The Sand Engine project combines a 'hard' measure (artificial sand addition) with 'soft' natural processes (sea currents gradually spreading this sand along the Dutch coast) to offset coastal erosion over a period of 10-12 years (Janssen, Van Tatenhove, Otter, & Mol, 2014).…”

Hydraulic engineering in the social-ecological delta: understanding the interplay between social, ecological, and technological systems in the Dutch delta by means of “delta trajectories.”

“…North Sea currents slowly erode an artificially constructed sand island, dispersing its particles along the coast. This compensates for erosion in sections along the coast just north of the project site, which would otherwise require large scale-sand supplementation (Janssen et al 2015). Similar plans have been proposed for the southwest delta region (Grontmij 2012).…”

Salt marshes for flood risk reduction: Quantifying long-term effectiveness and life-cycle costs

“…In contrast, when working with foreshores, measures should fit in the large-scale physical and ecological system, which requires a multi-disciplinary approach to flood protection. Although decision making can be more challenging and time-consuming, combined benefits for flood protection and nature conservation can potentially be improved if such an integrated approach is adopted (Janssen et al, 2015).…”

“…And second, because these solutions should often be realized in ecologically sensitive and protected areas. Therefore, successful implementation of nature-based solutions requires different governance and institutional arrangements compared to traditional flood risk management (Janssen et al, 2015;Borsje et al, 2017). More research on this aspect can help in getting nature-based solutions in the mainstream of coastal protection.…”