Summary

A water square retains water during peak rainfall, easing the stress on sewage systems and preventing floods in highly urbanised areas. Officially opened in December 2013, Rotterdam’s Benthemplein is the first full-scale water square in the world.

What is it?

A water square retains rainwater as it falls on the square itself and serves as a repository for rainwater falling on the roofs of surrounding buildings. A water square also doubles as an urban public space – the lowered areas designed to retain water can be repurposed for sports and recreational use during dry weather. The Benthemplein, for example, offers room for basketball, skateboarding and performance arts within pits that can also hold up to 1.7 million litres (around 449,000 U.S. gallons) of water during rainfall. The water is infiltrated into the soil beneath the pavement or pumped out to canals elsewhere in the city.

The concept of the water square was created mainly for areas that required additional space for water storage, without traditional options such as canals.

How does it work?

The Benthemplein water square retains water from the square’s pavement as well as rainwater from rooftops of surrounding buildings. As a result, these buildings’ wastewater pipes have been disconnected from the Rotterdam sewage system.

The water square retains water during peak rainfall, easing the stress on the city’s sewage system, which in turn prevents urban floods. It also helps the city avoid the significant financial cost associated with upgrading sewers in the future.

People around the Benthemplein were encouraged to share their ideas on possible functions for the reconceived square. Urban sports enthusiasts, for example, saw alternative uses for the space early on, and began removing barriers to the square during weekends before construction was finished. As a result, the Benthemplein has been used extensively for sports purposes since its completion.

Next steps

More space for water is needed throughout Rotterdam’s urban areas, and after the success of the Benthemplein, water squares have proven they are a viable – and multipurpose – solution. The construction of more water squares in Rotterdam is likely to follow.

Contact

City of Rotterdam

Rotterdam Office for Sustainability and Climate Change

Arnoud Molenaar

+31 (0)10-2672939

a.molenaar@rotterdam.nl