COASTAR, one of the water-future visions at the Rotterdam biennale

Opening of DOWN TO EARTH exhibition at IABR

On 19 September, the International Architecture Biennale Rotterdam (IABR) opened with the exhibition ‘Drought in the Delta’, for which KWR and its partners provided input. The IABR is a biennial international architectural event that focuses on the future of the city and its surrounding region. The theme of this ninth edition is ‘Down to Earth’. Among the features of the opening exhibition is the future vision of COASTAR: large-scale freshwater provision through a smart use of the subsurface, both in and behind the dunes in low-lying areas of the Netherlands.

COASTAR was developed – from concept, to exploration, to pilots – over the last few years within a TKI knowledge programme under the leadership of KWR, Deltares and Arcadis, and with the participation of the drinking water utilities Dunea, Evides and Oasen of the Province of South Holland.

Animation of the Dutch Delta

How can the water buffering capacity of the delta be increased? Led by landscape architect and urban planner Marco Vermeulen, experts looked for answers to this question for two years in the IABR-Atelier Drought in the Delta. The outcome of this ‘designing research’ is visualised by means of a 30-meter wide, 3.5-meter high animated cross section of the Dutch Delta. In about seven minutes one can see how our delta currently functions, what problems have arisen due to climate change, and what possible building blocks might exist for a new, collective freshwater strategy, in conjunction with other transition challenges, such as the energy transition, food production and urbanisation.

Artist impression van de animatie van Atelier Droogte in de Delta © IABR, Studio Marco Vermeulen

Artist impression of the Atelier Drought in the Delta animation © IABR, Studio Marco Vermeulen.


Four exemplary Dutch projects that offer concrete solution paths for a new freshwater strategy are also featured. COASTAR is one of these paths, and Vitens’ Panorama Waterland is also presented. COASTAR focuses on a large-scale freshwater provision through the smart use of the subsurface. Freshwater storage in the saline subsurface bridges the time and spatial discrepancies between water demand and water supply. COASTAR also tackles the increasing salinisation, by extracting brackish groundwater and using it for the production of freshwater.

Concrete applications

COASTAR was developed over the last few years within a TKI knowledge programme with the participation of KWR, Deltares and Arcadis, and the business community and governments in the Province of South Holland: from concept, to exploration, to applications. One of the concrete applications is the implementation of brackish water extraction from under the dunes, which will be tested in practice by Dunea and KWR starting next year. This pilot is part of the EU LIFE Freshman project, in which De Watergroep, the water utility IWVA and Allied Waters are also participants.

The IABR ‘Drought in the Delta’ exhibition can be seen from Saturday, 19 September, through to Sunday, 18 October, in the Keilezaal, Keilestraat 9-K1, Rotterdam. Since visits are organised by time slots, reservation is necessary.