Water Storing Greenhouse Roofs

Image: v-shaped gutters between pitched greenhouse roofs creates a water-warehouse

Innovation Comes Flooding In at Westland Greenport


From the air, Westland Greenport is an impressive sight – 40 square kilometres of greenhouses dazzling in the sun. We know it as the Netherlands’ largest greenhouse horticultural district. You may know it as home to the world’s largest flower auction - but did you know that we are implementing innovations here that can reduce flood risk whilst maintaining the same production area?

Flooding can be a major challenge for large-scale horticultural districts, but now, thanks to a highly innovative joint programme between Royal HaskoningDHV and TNO, Westland is getting ready to say goodbye to the increased risk of flood and hello to sustainability, increased production space, and reduced costs.

The solution is Water-Storing Greenhouse Roofs, a beautifully simple concept that does just that – creates a water-warehouse along the v-shaped gutters between pitched greenhouse roofs.

This system of temporary storage is an incredibly cheap intervention that not only reduces flood risk but frees up space for much-needed profitable horticulture. The concept of Water-Storing Greenhouse Roofs enables the storage of rainwater in the water gutters and flattens discharge peaks at the same time. This could be a significant development in maximising the storing of water from heavy summer showers in times of drought.

Image:Model shows the functionality of the v-shaped gutters.

This is a smart innovation that addresses our ever-changing climate, the needs of a growing population, government budget constraints, and calls to boost the sustainability of the water supply chain - but it has its roots in detail too. The concept is exceptionally low maintenance, it is self-cleaning allowing for leaves to be washed away, and crucially, it requires no external energy - working mechanically on the basis of hydraulic laws.

Royal HaskoningDHV is keen to see the system fully implemented in Westland and in other areas where flood risk is high. The company is grateful for the continued support of a variety of stakeholders: the Water Board of Delfland, the Municipality of Westland, the Province of Zuid-Holland, Rabobank Westland, LTO Noord Glaskracht, TNO, and Demokwekerij Westland.

For more information on this project, please contact wouter.berkhout@rhdhv.com