Water storage in heavily built-up areas is and remains a challenge, especially in the face of climate change, as rainfall is becoming more intense and less predictable. Royal Haskoning DHV, Demokwekerij Westland and TNO have developed an innovative weir bulkhead to store rainwater on greenhouse roofs. The project partners are developing and testing the concept with, for, and at companies active in the sector.

As a result of climate change, rainfall is becoming more intense, less predictable, and interspersed with periods of drought. This has consequences for the approach to water storage in heavily built-up areas. The Westland greenhouse region in the Netherlands is just such an area.
In this project, Royal Haskoning DHV, Demokwekerij Westland and TNO developed an innovative weir bulkhead that can temporarily store rainwater on a greenhouse roof. That bulkhead must not interfere with the normal use of the greenhouse. After development of the bulkhead, field testing will be performed at Demokwekerij Westland. In cooperation with HHS Delfland, an implementation plan for the real-world situation will be devised. The concept must be space saving as well as sustainable, effective, affordable and innovative.

Benefits to the grower

Some important advantages of this concept for a grower (and other stakeholders in the region) are:

  • Less risk of flooding
  • Lower water management authority taxes
  • More usable land (cultivation area)
  • More rainwater in the storage basin


The following plan has been established for carrying out this project:

  • Conceive, design, and develop a concept for the weir bulkhead
  • Build a demonstrator (small greenhouse roof) where the concept bulkhead will be installed
  • Use the demonstrator to thoroughly test how well the bulkhead functions
  • Identify and implement any necessary changes to the bulkhead
  • Draft an action plan for the practical test (what, how, when, why, how long, with what, with whom?)
  • Purchase necessary measuring instruments and tools
  • Install everything needed to start the trial
  • Conduct the trial (including regular inspection and maintenance)
  • Process the measurement data and draw conclusions
  • Draft recommendations for project follow up and scale up (practical implementation at one or more growers' operations)


Karl Sewalt MSc

  • product innovation
  • product development
  • industrial design engineering

We use anonymous cookies to enhance the use of our site.