Infrastructure

Rotterdam Zoo implemented a circular water system beneath its main square to address soil subsidence, flooding during heavy rainfall, and growing water scarcity, enabling the reuse of up to 8 million liters of rainwater annually. In collaboration with BufferBlock, rainwater from the square, surrounding paths, and roofs is captured, temporarily stored underground, purified through a customized BlueBiofilter, and then stored in an existing rainwater cellar. The treated water is reused across the zoo for applications such as irrigating tropical plants, with excess water redirected to supplement the groundwater system, reducing reliance on drinking water and maximizing sustainable water use.

In Cromvlietpark in The Hague, a sustainable water management system was implemented to capture, treat, and store rainwater and surface water for reuse in community gardens, green spaces, and an urban animal farm. As part of the park’s renovation, stormwater from 8,500 m² of surrounding streets, roofs, and walkways, along with seasonal surface water from the Noordpolder canal, is collected and buffered underground, treated through a BlueBiofilter, and infiltrated into a deep aquifer for long-term storage. The stored water is later abstracted via a dedicated well and reused for irrigation throughout the park, reducing sewer discharge while enhancing the park’s environmental quality and resilience.

At Caleido Park in Madrid, an on-site stormwater collection and treatment system was implemented to sustainably supply and maintain the park’s central architectural pond. Rainwater runoff from both green and paved surfaces is captured, stored underground, and treated through a BlueBloqs Loop system with an integrated BlueBiofilter, creating a closed-loop circulation that continuously maintains water quality. The pond functions as both an ornamental feature and a rainwater retention basin, reducing reliance on potable water while supporting the City of Madrid’s climate adaptation and sustainable urban drainage goals.

At TU Delft’s Green Village, the BlueBloqs Loop system is being tested at Het Hitteplein (“Heat Square”) as a field-scale pilot focused on climate adaptation, drought resilience, and water reuse. Rainwater runoff from 1,600 m² of paved and roof surfaces is collected, stored just below ground, and treated through four parallel BlueBiofilter units with different media and designs to evaluate real-world performance under varying environmental conditions. The treated water is reused on site for toilet flushing, irrigation, and demonstration purposes, while also supporting urban greening and biodiversity, providing valuable insights into practical, accessible circular water systems beyond controlled laboratory settings.