A Sponge on a (Water) Table by

2023 Other / Belgium / Built in 2023 /

Management of flood risks calls into question our contentious usage of space, as a limited resource in terms of the biosphere. In Brussels, reassigning space to rainwater in the densely developed city has to become a priority and incite innovative landscape visions. Although there is a growing awareness of the role of landscape architecture, it is not yet dealing fully with the issues that we are seeking to address, while the implementation of projects remains inadequate and far too slow. In the translation of its ambitions into actions, Landscape innovation in Brussels could take place through a stronger mobilization of design thinking. The challenge is to realign spatial projects with natural, social and economic resources, mobilizing opportunities in the reinvention of the city.

In a context of urban densification, the value of existing urban park is not yet to be contested. In Brussels nevertheless most of them being under heritage jurisdiction, they are considered as frozen images of nature. The attentive examination of existing ground conditions leads to responsive design strategies to adapt those needed spaces to current socio ecological challenges

This submission aims to highlight how our expanded practice has developed a self initiated research on Brussels water culture. The project can be see as a “project of projects” consisting of implemented design, design investigations, exhibitions, events and publications. Doing so, three roles have been endorsed.

The initiator

The project “water line” is the first water sensitive project implemented along a watershed in Brussels. It has been developed with the precious mobilization of citizen sciences and the emerging will of the municipality of Forest to develop a “water matrix”.

The advocate

We used an invitation to participate in the second Brussels urban landscape biennal (Bulb) as a research tool. It enabled us to demonstrate that to fully respond to water stress along the watershed of Forest, the response needed to speed up actions and mobilize 10X more spaces that the “water matrix” envisioned by the city. We identified this as a leverage to mobilize frozen and latent landscapes in a water responsive strategy. Our design research demonstrated that major public parks (3) that are in need of renovation could potentially become an excellent network of “sponges”, filters that supply public drinking water; evolutions in our means of transport are leading to a new way of considering our rail networks as supports for mobility and biodiversity (1), and our streets (1) as networks of gardens. Urban industry in the paths of prevailing winds can contribute to cooling and improving the water quality of the Senne and the canal, or even local water production… Our research insisted on the necessity to tackle frozen landscapes, composed of 19th century heritage parks. Most of them are possible sponge parks sitting on top of forgotten valleys.

Those findings could be replicated across the region.

The critic

Our work exhibited in the Bulb has impacted mindsets and we were asked to design the water-biodiversity adaptation the most iconic park in Brussels (Josaphat).

What is at stake? We deal here with a real paradox. The park was conceived as part a piece of a valley, but its current water management entirely ignores this topographical conditionit. Above the ground, the architect Galopin orginally designed the park as a succession of scenes of nature along several lakes with very poor biological/ecologicalliving quality. Under the ground a vast pipe and pumping systems bring the water to the top of the park featuring a cascade. Working closely with hydrologists and biodiversity experts the design research attestss the potential of the sandy ground to infiltrate and retain water above the clay. We discovered that the woodedn hills of the park can become a vast water reservoir that enables theo supply of a constant flow of water into the pond system. In short, we acknowledged the ecology of the valley as an alternative to the obsolete technological design of the park

Our approach entitled “a sponge on a table” is a critic of the picturesque legacy that predominate in Brussels, where landscape architecture is understood as a set of scenery to stroll through. In opposition we propose to re enact a real and tangible re-connection to ground condition and water cycles acknowledging the presence in Josaphat park of the source of the main Brussels water table.

Regrounding the park in the valley system opens up several opportunities for the spatial adaptation of the park. The water table encounters the clay at several locations and e. Each emergence encounter become the supports of a design proposalition that will targets one of four incremental interrelated objectives. An improvement of water flow and water quality in the park (1) enables the creation of robust ecosystems . These ecosystemsat allows for an improvement of the cooling of the park, supporting a greater diversity of usesnew public practices.

This proposition addresses the potential of an invisible ground soil condition in Brussels: ; when sand beds encounter clay layers, subterranean water oozes across large neglected liminal spaces.


Forest East Station, 1190 Forest, Brussels, Belgium

Josaphat park, Av. Louis Bertrand, 1030 Schaerbeek

Design year: 2017-2023


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