This flood hazard map identifies areas where flooding (of low, medium or high magnitude and frequency) could occur as a result of overflowing streams, runoff, sewer backups or sewer backups. temporary rise in the water table, even in places where no flooding has been recorded so far. The protective effect of collective storm basins is taken into account in this hazard map.
The absence of a hazard zone on the map cannot guarantee that a flood will never occur there, as some causes of flooding are not taken into account such as a local fault in the drainage network, a accidental obstruction of it or failure of the pumping system.
Categories:
- Low hazard: potentially floodable area, but very exceptionally: approximately once every 100 years.
- Medium hazard: potentially floodable area, but quite rarely: approximately once every 25 to 50 years. They represent
5% of the territory.
- High hazard: area where flooding is observed recurrently, at least once every 10 years. High hazard areas represent 1% of the territory.
Forecasts, not certainties ...
The map is based on scientific studies, but the information is nevertheless of the order of the forecast: a flood may be more important than expected, put longer than expected to be absorbed, ... As new parameters (urban planning, climatic, topographical ...) can modify the situation, we update the map regularly.
Forecasts based on evidence
The map is based on topographic modeling, which identifies areas of waterlogging, concentration of flows or expansion of floods. It was also carried out on the basis of flood observations collected by SIAMU, the Calamities Fund and Vivaqua.
Bruxelles Environnement: https://geodata.environnement.brussels/client/view/1a3cae6b-dd04-4b28-a3e2-c432dc83e24f