Mechelen narrowly avoids flooding after lock malfunction

Updated 3 September 2026 — MECHELEN. A malfunction at a lock sent the Binnendijle in central Mechelen sharply above its normal level on Tuesday morning, but staff from De Vlaamse Waterweg intervened before the river entered nearby homes or tore floating pontoons from their fittings. The Flemish waterway authority told Het Nieuwsblad that too much water passed through the lock, raising the river by about 70 centimetres above the level normally permitted.

Visiting pleasure-boater Els Vermeylen noticed the unusually high water at around 07:30 and alerted the lock keeper, according to Het Nieuwsblad. The warning came before the expected high tide at about 09:00. De Vlaamse Waterweg then lowered the level gradually over several hours so that boats and floating infrastructure could descend safely with it.

At its peak, the Binnendijle reached approximately five metres TAW, the Belgian reference system used for elevation and water-level measurements, De Vlaamse Waterweg spokesperson Max Verdonck told the newspaper. The authority said the situation was under control by Tuesday afternoon. No flooded home, injury or major infrastructure damage was reported in the available accounts.

The margin was nevertheless small. Resident Veerle Vanhuyse told Het Nieuwsblad that water reached within centimetres of her doorstep and pushed a small inflatable boat partly onto her terrace. Temporary harbourmaster Joost Vanheusden said several pontoons rose beyond their normal guide fittings. Boats are attached to those structures, so a pontoon breaking free would have created an additional hazard.

Mechelen’s own planning documents explain why the episode was exceptional. The city says two locks regulate the 2.5-kilometre Binnendijle and largely shield the historic centre from the Dijle’s tidal movement. A municipal water study sets the target level at 4.25 metres TAW and identifies 4.85 metres as an extreme high level. Tuesday’s reported peak therefore exceeded that planning benchmark.

The event directly concerns residents, boat owners and people using the floating Dijle path. It also tests infrastructure that allows Mechelen to keep a controlled urban river running through densely built neighbourhoods.

De Vlaamse Waterweg is investigating whether the excess inflow resulted from a technical fault, human action or a combination of the two, according to Verdonck. The next substantive update should establish which lock was affected, why safeguards did not prevent the rise and whether inspections or operating procedures will change.