‘Water comes from all four sides’: how Rotterdam’s tidal park protects the city
[...]
But it’s also a present and future relationship, as sea levels rise and the climate crisis is linked with more severe bouts of rainfall. “In Rotterdam, the water comes from all four sides,” said Van Peijpe. “Delta cities are vulnerable to climate change, especially to sea level rises, which are happening faster than expected, but also to what comes from the rivers. There is an increase in heavy rainfall – alongside drought – and also rising groundwater, often in combination with subsidence.”
In December, Storm Pia and extreme precipitation hit: Rotterdam closed its Maeslant storm barrier for the first time to protect against storm surge while other areas piled up sandbags against unusually high water in the Maas and Rijn rivers and the IJssel and Marker lakes.
[...]
A €2.3bn “Room for the River” project – making floodplains at more than 30 locations on four rivers – is credited with saving the country from the worst flooding this year. The national delta programme is investing in action to guard until 2050, and a multi-billion euro flood protection programme (HWPB) involves 100 projects to strengthen kilometres of dykes, without which, says Rijkswaterstaat infrastructure organisation, 60% of the country would regularly be under water.
But in cities, too, water protection must meet urban design to create an attractive, adaptive city, says Arnoud Molenaar, Rotterdam’s chief resilience officer. A vast amount of work has been going on, and the city has built water squares, green and blue roofs and a 2km-long railway viaduct rooftop park. The water squares, also designed by De Urbanisten, are, very simply, built in overflow areas – when there is too much rainwater they fill up, and then slowly drain away so that the storm drains are not overwhelmed. And when the water has gone, they become public spaces again.
[...]