It is almost impossible to imagine our current events without it: the Flemish groundwater level is alarmingly low because of persistent drought, while at the same time parts of Flanders are struggling with heavy flooding. The winter of 2024-2025 was another recent example of such an exceptionally wet period. These extremes show that our water resources are under pressure, and that sustainable water management is no longer an optional extra.
So today we highlight for you the Stormwater Ordinance.
What does that mean for you?
Anyone applying for an environmental permit – whether for new construction, expansion or reconstruction – faces strict regulations on how to handle stormwater. Among other sector legislation, the Stormwater Ordinance must also be strictly adhered to. This ordinance was recently renewed and emphasizes natural infiltration of water into the soil. Each application must accurately calculate how many square feet of pavement will be added, and specify the facilities through which stormwater will be collected, infiltrated or reused.
“Mitigation” measures are provided for existing buildings, but the puzzle remains technical and detail-sensitive. Indeed, an error or incompleteness in the application file can lead to significant delays in the permit process – or even a complete denial of the permit. By providing water collection and infiltration promptly and correctly, you avoid additional costs and subsequent adjustments. Moreover, you are building a future-oriented project where sustainability and regulation go hand in hand.
In short: those who follow the rules correctly save time, money and worry.
Why these rules are there: the broader picture
The revamped ordinance relies on three core principles: water retention, storage and only as a last resort discharge. In doing so, she connects with the growing realization that stormwater should not simply be disposed of, but managed locally. The impact of weather extremes is making itself increasingly felt, as the Department of the Environment also points out. Recent years have been alternately marked by prolonged droughts and widespread floods. The outlook for the next few years predicts a similar pattern.
So the goal is to maximize every drop of water on site to bridge dry periods as well as reduce the impact of paving on flooding. This requires not only collecting stormwater, but more importantly, keeping track of it and reusing it. This can be through rainwater cisterns, infiltration facilities or reuse systems (for example, for toilet flushing or garden watering). In this way we will be more economical with the liquid gold that flows from our tap during periods of drought, as well as guarding against peak loads during heavy rainfall.
Thus, compliance with the Stormwater Ordinance is not only a legal obligation, it is also a social responsibility. What you do on your plot today has a direct impact on collective water management. You help prevent floods, mitigate droughts and maintain our water resources. Every builder who participates contributes to a climate-robust Flanders.
What can we do for you?
At LAWTREE, we are happy to assist you in putting this complex puzzle together correctly. We help you interpret the regulations, translate them into practice, and align your permit application with the legal requirements. This ensures that your file is legally correct, and that you are building a project that is completely future-proof both legally and ecologically.
