The Bufferblock is a concrete block which is placed underneath a water porous/permeable street and acts as a stormwater buffering/attenuating drainage system during heavy rainfall. The highly effective water buffering and infiltrating properties of the block make sure that the sewer systems in urban areas will not get overloaded during heavy rainfalls and streets will not get flooded.
Technology demonstrated in relevant environment.
Representative model or prototype system, which is well beyond that of TRL 5, is tested in a relevant environment. Represents a major step up in a technology’s demonstrated readiness. Examples include testing a prototype in a high-fidelity laboratory environment or in a simulated operational environment.
The prototype of the Bufferblocks has been tested with computer simulations (finite element analysis) and strength tests in the lab of the factory where the concrete prototypes have been manufactured. A pilot with Bufferblocks is placed at the Green Village in Delft since March 2018.

How does it work?

The concrete Bufferblocks are designed to be placed underneath a permeable/porous street layer. This can be a top layer of permeable pavement stones or porous asphalt. During heavy rainfall the stormwater will go through the top layer and through a thin layer of drainage sand and a geotextile and then inside of the Bufferblocks where the stormwater is stored and eventually infiltrates into the ground or is redirected to a sewer system. Because the stormwater is temporary stored inside of the Bufferblocks, the main sewer system will not get overloaded by a peak in water discharge due to the rainfall.