Waterweg turns dredged sediment into rain-permeable paving

Sedimentation is a natural process, but clogs up rivers if the accumulation of silt, mud and sand isn't regularly dredged. An estimated 200 million cubic meters of material are cleared out of European waterways every year.

Dutch entrepreneurs Wies van Lieshout and Eva Aarts found a way to use that fluvial waste stream to tackle another water-related problem: paved-over cities not being able to handle extreme amounts of rain falling in a short period of time. Their solution? Waterweg — a permeable paver made of locally dredged sediment.

Waterweg tiles are designed to let water pass through, which is one way of making cities more rainproof. As cloudbursts are expected to increase in frequency as a result of climate change, urban design needs to adapt to prevent floods and overflowing sewage systems.

The result of a 2018 design challenge by the Delfland Water Authority, Waterweg also worked with Rotterdam to process 15,000 kg of dredged sediments into city pavement. It's now finetuning prototypes and processes for its latest tile designs. Recently, the start-up was short-listed for What Design Can Do's No Waste Challenge.