On 7 September at 11 am CET via Zoom Nieke Hoenjet, until recently with Wageningen University & Research, where she holds an MSc in environmental sciences (specialisation in water systems and global change), presented her research findings which sought to extract lessons from the technical aspects of implemented natural stormwater systems (NSTS) in order to allow medium-sized cities to build upon these experiences. The NSTS being evaluated are wadis (swale trench systems) and water machines (constructed wetlands) in the Dutch cities of Breda, Enschede, and ‘s-Hertogenbosch (Den Bosch). One of the objectives of Nieke’s presentation and Q&A is to discuss with NBS practitioners and researchers the potential transferability of these case studies to other contexts.
Presentation Slides – PDF
Understanding the implementation process of natural stormwater treatment systems (NSTS) in medium-sized cities in the Netherlands has currently not been adequately investigated. NSTS address both social and environmental challenges and contribute to more climate resilient cities. In this study the lessons learned about the technical aspects of implemented wadis (swales) and water machines (constructed wetlands) are evaluated in three mid-sized Dutch cities. Semi-structured interviews were held in Breda, Enschede and ‘s-Hertogenbosch about the motivations to implement wadis and water machines, the functioning of these systems, the influence of technical aspects, and the perceived performance in improving urban surface water quality. The technical aspects include 1) construction codes and standards, 2) local characteristics and techniques, 3) tools, and 4) knowledge and experience. The last aspect was found to be the most important technical factor for successful implementation of these two types of nature-based solutions (NBS). But more importantly, the informants mentioned that the technical aspects were not essential for success. This research showed that good communication, goal-oriented designs, early division of responsibilities in the project and working together with different organizations, were more important. The perceived performance of the case studies was all fair, good or excellent, meaning that indeed these types of NBS contribute to a better urban surface water quality. It is recommended for municipalities to include all stakeholders from the start of the project, including the users and maintainers. Additionally, sharing knowledge and experiences on green climate adaptation measures with other cities will help to faster upscale these types of NSTS in other similar sized cities.