Het testen van de BlueBloqs Loop op het Hitteplein, Technische Universiteit Delft

Climate adaptation is not just about managing floods—it also means ensuring water availability during longer periods of drought. Following the success of the Waterstraat project, TU Delft’s Green Village created Het Hitteplein ("Heat Square") to showcase and test innovative solutions to drought and heat stress. BlueBloqs Loop is one of three climate-adaptive technologies being tested in this environment.

This pilot provides a critical opportunity to observe how the BlueBloqs system performs in real urban conditions—offering insight beyond what controlled lab studies can provide. The outdoor setting allows researchers to test how variables such as temperature, sunlight, storm events, and even wildlife (such as nesting geese!) affect the system.

BlueBloqs Loop is a field-scale research and development setup for biofiltration and water reuse. This particular test focuses on the BlueBiofilter, with multiple variations of filter media and design tested in parallel. Four separate one-cubic-meter biofilter units, each with unique configurations, are used to analyze water treatment performance under real-world conditions.

Unlike previous BlueBloqs systems, water is not stored deep underground but just below ground level, enabling easier implementation in diverse locations and creating a more accessible circular water model.

Rainwater runoff from 1,600 m² of paved and roof surfaces is collected via open stormwater drainage channels. It flows to a 10 m³ HDPE buffer tank installed beneath concrete paving. The water is then evenly distributed into four biofilter cells, each engineered differently for targeted removal of nutrients and metals.

The treated water converges in a final sump tank. From there, it is reused to flush toilets in the NoNo House demonstration facility and is also made available for irrigation, demonstration of other technologies, and general water reuse on site (e.g., filling buckets for showcasing permeable pavements or other heat square features).

This installation also includes a small landscaped green space adjacent to the filters to demonstrate the role of stored water in irrigating urban vegetation, contributing to urban greening and biodiversity enhancement.