It is dry early: water managers are already taking measures

It’s dry early. Two months earlier than usual, the water managers of the Delfland Water Board take measures to limit the harmful effects of the lack of fresh water: salinization of the country and the water, cracking in dry cleaves. « Usually the salt is just around the corner at the beginning of June, » says Martijn Heinhuis, Water Management Expert of Delfland. But hardly any rain has fallen for weeks and the salty water is already moving on to the polders, especially via the locks on the border of Nieuwe Waterweg and Oude Maas. That salty water is washed back.

And so the Water Board leads extra fresh water in two places: in the south of the area from the Brielse Meer and in the north, here, at the Dolk pumping station in the center of the Oude Leidschendam, next to the lock in De Vliet, the waterway between Leiden and Delft. That supply route is partly provided by colleagues from the Rijnland Water Board. « That’s how we help each other. » Only some bells betray that on average fifteen hundred liters per second flows in. The extra water ensures that the water level in the bosom waters of Delfland remains the same everywhere: 43 centimeters below NAP. Heinhuis: « That level is a very precise size for which all interests have been weighed. We only accept a deviation from that level for a short time, if it really can’t be otherwise. »

Water boards are expected to move with all those extremes. But the pressure on our system is now becoming very large, also due to an increase in the demand for water due to growing activities and numbers of inhabitants

Groundwater not on the golf course

In the months of February and March and in the first ten days of April, exceptionally little rainfall fell in the Netherlands. In March, on average about 6 millimeters of precipitation fell against normally 53 millimeters, and that is again a record, the umpteenth in times of climate change that, at least in the Netherlands, is mainly characterized by the increase in extreme weather situations: more heat, more periods of drought and flooding, sudden cries. The first, usually preventive measures have been taken throughout the Netherlands. In four regions in the northern part of Brabant, the grassland of farmers, but also football fields and golf courses, is not permitted with groundwater.

A « unique » measure, says Jos Kruit, drought coordinator of the Aa en Maas water board in the northeastern part of Brabant. Whether the measure immediately has a lot of effect on the groundwater level is considered. Kruit: « What we mainly want to achieve with it is that we are careful with groundwater that is still there today. So that if the drought persists, there is also still if we also need that water in the summer. Moreover, we want to send a signal with this measure that groundwater is no longer something that you can continue to grab. »

Water is becoming more valuable and that awareness is getting bigger

As a good example, Kruit mentions a football club in Sint-Oedenrode near Den Bosch, who had a water basin installed under the main field. « Water is becoming more valuable and that awareness is getting bigger. » According to Kruit, the current situation in Brabant is by no means dramatic. « Our streams are still flowing, and that is a good thing because this is the time in which fish want to migrate and reproduce upstream. » However, the water board has already taken other preventive measures, such as ‘buffering’ of extra water, to be precise twenty centimeters higher level, in the Drongelens Kanaal.

Alert, but not panic

Even in the rest of the Netherlands, the consequences of the drought are not yet serious. « We are alert but there is no panic. The situation is easy to handle, » said a Rijkswaterstaat spokesperson. But the changes are huge. Where in the last year and a half, after years of long -term summer drought, the groundwater levels had been given a huge boost due to persistent, abundant rainfall, it has suddenly been completely dry. Moreover, relatively little river water comes in the Dutch direction. The reservoirs in the river area of ​​the Rhine are not full, there is little snow in the Alps, the level of the Swiss bodenmeer is low. The ‘drain’ of water in the Maas is also slowly falling. In addition, the available water quickly evaporates. « The water evaporates like a madman with all that sun, » says a spokesperson for the Union of Water Boards. « Hang your laundry outside. It will be dry in no time. »

In this way, nature and the farmland also quickly dry out. And that while the demand for water naturally increases in the coming months. The farmers do not yet complain en masse and a spinach grower from Lies in Brabant, who still saw his harvest in part last year due to the persistent rain, even speaks of ‘perfect’ weather. « I hope it will not rain too hard soon. » But with persistent drought, there cannot be any harvests and damage to nature.

One of the biggest problems in the coming years, and already, is the salinization. The Hunze and Aa’s water board, in the east of Groningen and the northeast of Drenthe, has been supplying water from the IJsselmeer for ten days; There was too little fresh water to be able to rinse to the sea and therefore the salt content of the water in the Eemskanaal rises. « We still have enough water now, » says a spokesperson.

All together in a bathtub

Back to Leidschendam. What would happen if the drought persisted and the Delfland Water Board would not have fresh water press? Then the clay dikes could tear and, in the worst case, collapse, with the deterrent example of moving away a dried -out Veendijk in Wilnis, more than twenty years ago, during a dry summer. Something like that, says water advisor Martijn Heinhuis, is disastrous in an area that is much lower than the water in the bosom, such as De Vliet. « We all live here in a bathtub. So safe dikes are prio one. »

In addition, the salinization is also a serious threat in Delfland. “To begin with the salty seepage. That is sea water that slowly seeps in. In addition, and for us more important, leaking salt water through the locks near Rotterdam. When ships, salty water flows in through the lock. We go against that by letting fresh water, and we go, for example, the salinization of the Schie and the Hague. Water does not benefit from salt water, certainly not in the spring.  »

Elastic water management

What affects almost all water managers is the speed at which the weather extremes occur. As a water manager you nowadays have to be exceptionally flexible, as it were of elastic, in order to be able to cope with extreme and, moreover, changing circumstances. Because now, citizens over water in their cellars and see farmers see their harvest are destroyed by too much water, such as last year, and then again there is too little water.

« We have to move or adap or how you want to call it all, » says Droertoordinator Jos Kruit of Water Board Aa and Maas. The help of citizens is needed, according to water adviser Martijn Heinhuis van Delfland. « We are expected to move with all those extremes for a while. But the pressure on our system is now becoming very large, also due to the increase in the demand for water due to growing activity and numbers of inhabitants. Also people themselves have to do more. Not only shoot in panic mode if they are no longer allowed to fill their swimming pool. Not dependent on the supply of fresh water from outside.

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