Stormwater management in Brussels-Capital Region: in transition towards a Water Sensitive City

This research explores how alternative actions contribute to a transition in the stormwater management in dense urban areas with a low level of water-related hazards, such as Brussels Capital Region (BCR).

Worldwide, urban areas are being challenged to improve the stormwater management regime (i.e. the totality of beliefs, rules and practices that guide water management activities). Illustrated as the Water Sensitive City, the envisioned new regime aims to solve water problems, to adapt to future uncertainties (e.g. increase of extreme events), to create a more liveable urban environment and to reflect the aspiration of the community related to water.

In BCR, the regional administration still relies on a centralised decision-making process to extend current infrastructure using conventional actions, such as underground retention basins. Meanwhile, the overflow of the combined (stormwater with wastewater) sewer system during large precipitations – leading to urban flooding in streets and household basements and to pollution of surface water – reveals a weakness of the current regime. External pressures from the European water directives impose a reduction of water-related hazards, integrated water management and public participation in the process. These conditions open up the possibility of the emergence of alternative actions. At local level, neighbourhood committees, non-profit organisations and municipal public administrations propose alternative actions to harvest, infiltrate and drain stormwater on the surface by including various stakeholders (and citizens) in a co-production process. Thus, the question arises: to what extent can alternative actions trigger the transition towards a new stormwater management regime?

The thesis addresses this question by (i) illustrating the characteristics of the existing regime in BCR, (ii) by analysing changes proposed by alternative actions developed in three case studies in BCR (Ilot d’eau design initiative, Forest-Vorst municipality and Molenbeek Valley) and (iii) by discussing the lessons learned in order to understand whether the diffusion of knowledge and the transition roles of the involved actors can be perceived as signs of transition.