How Dutch growers help solve flooding problems

In case of heavy rainfall, Dutch growers free up capacity in the reservoir via a specially constructed pipeline. This way, they have more space to collect the water. Project manager Saskia Jouwersma: "The Delfland region consists for 10% of greenhouse horticulture. So this solution for flooding was obvious."

If heavy rainfall is expected, connected growers automatically will receive a message. This states how much space they ideally should make available in their reservoir. Tomato grower Teun Varekamp from De Lier participates in the project. "The system is becoming more and more professional, we receive good advice and in the implementation we can take the different seasons into account. For example in the spring you can miss less water than in September when there is more rain."

Of the 4,000 hectares of greenhouse horticulture in the Delfland region, 66 hectares are currently connected to the project. Saskia: "This is only a fraction, but many growers have plans to join in. We approach growers who are replacing the foil in their reservoir, which is the ideal time to step in because at that time the drain pipe can be installed easily. Our goal is that in 20 years time 80% of the growers in the Delfland Region will be connected to the project. This corresponds to the lifespan of the foil."

Both Teun and Saskia emphasize that every grower helps. Teun: "The more people join in, the better it is. Often you see that those who have a lot of flooding are the first to join the project." This also applies to Teun himself. In addition to his participation in the project, he has also taken some other measures to limit flooding. "With heavy rainfall in the past it has been critical a few times. Which is why we have raised the level of the ground and installed a plastic edge around the greenhouse, so that the water can’t flow in anymore."

Saskia: "Every grower who meets the admission conditions may participate in the project. The most important of these conditions is that no condensation water may flow from the greenhouse into the reservoir, because we do not want any residues of crop protection agents to end up in the surface water. Not every grower has the means to make this adjustment."

We are looking at other opportunities to introduce this project in more areas. Saskia: "We hope that we also get other regions to participate. Our partner LTO Noord Glaskracht is actively working on this. Individual growers can choose to manage their reservoir in this way, because our system is designed in such a way that it can be used everywhere. We have noticed that the project is already working on a very local scale. Participating growers who used to get their feet wet in the event of a heavy rain shower, now are already noticing the improvement.