Cities across the Netherlands are pulling out solid concrete and replacing it with grass-filled paving blocks that absorb rainwater and reduce urban heat. The shift is part of a broader push to help low-lying Dutch cities handle heavier downpours and hotter days. Permeable pavements like these are now installed at more than 1,000 locations nationwide.
The system uses concrete units formed in a grid or ring pattern, leaving open sections between the concrete. Those openings get filled with soil and grass instead of staying as bare concrete. When it rains, water moves through the gaps into the ground below instead of rushing to storm drains.
A study that measured infiltration rates at 33 grass-filled paving sites in six Dutch cities found results from 50 to 1,400 millimetres an hour, with a median of 344 millimetres. Conventional concrete or asphalt pavement absorbed about 3 to 10 millimetres an hour in the comparison cited in the report. The same mix of concrete, soil, and grass also changes how surfaces hold heat. Concrete and asphalt store heat and release it into the air into the evening, while grass and soil hold moisture that cools the surface through evaporation.
Arnhem is taking a big swing, targeting a 10 percent reduction in asphalt cover under a 10-year plan designed to absorb 90 percent of rainwater into the soil instead of the sewer system. City alderman Cathelijne Bouwkamp said rising temperatures hit hardest in areas dominated by stone and concrete.
The change is not limited to city streets. An annual competition called NK Tegelwippen, or tile-flipping, encourages residents to remove paving stones in their gardens and replace them with plants. Organisers report several million stones lifted so far, and Dutch water management specialists connect that effort directly to neighbourhood-level flood prevention.
Read the full, original article from Mjengo Hub here.