Circular water system at Blijdorp Zoo, Rotterdam

The main square in Rotterdam Zoo has suffered from soil subsidencein recent years, causing regular water stagnation during heavy rainfall events. Renovation of the square was planned for 2020. Rotterdam Zoo had the ambition to make use of this opportunity to simultaneously tackle the water problem and to focus on the local reuse of rainwater.

A circular water system for collection and direct reuse of rainwater was implemented in the main square in collaboration with BufferBlock. In this way, rainwater can not only be disconnected from the square, but also from surrounding paths and roofs and thus be utilised. In view of the high water demand of the zoo and the increasing pressure on the drinking water supply during dry periods, the reuse of rainwater is highly desirable.

After conducting a feasibility study, a design for a circular water system was developed to collect and reuse rainwater. Rainwater runoff is temporarily stored in a Bufferblock underneath the renovated square and purified by a customized BlueBiofilter. Blijdorp had an unused rainwater cellar, where purified water is now stored. From here the water is pumped up for use at various taps in the zoo, including for irrigating the tropical plants. When the rainwater cellar is full, the excess rainwater is used to supplement the existing groundwater distribution network. This way, water is put to good use.