The supply of drinking water to seven million Dutch and Belgians will be ‘at risk’ in the coming decades because insufficient water flows in via the Meuse for a long time during the summer months. Due to the low water discharge, drinking water companies that use the Meuse as a source may be forced to stop taking water for a long time. Several drinking water companies draw these conclusions from the results of research by knowledge institute Deltares into the future availability of Meuse water.
“The report confirms the trend of longer periods of low water discharge in the Meuse in the summer months, as we have already seen in recent years. This is an alarming trend that can lead to major problems in the drinking water supply”, write the drinking water companies Dunea, Evides and WML, together with the organization in which they have joined, RIWA-Maas. Three years ago, RIWA-Maas also warned about water scarcity.
Low water discharge in the Meuse – a river that mainly relies on rainwater – will become more frequent in the coming decades, especially in August and September. “In almost all KNMI climate scenarios, the discharges of the Meuse decrease in the summer months,” says Marjolein Mens, expert on drought and freshwater supplies at Deltares. “What we have done is look at what this means for the availability of drinking water with a new model, if you also take into account the influence of humans on this: the abstractions of water by agriculture, industry and drinking water companies, and the discharges into the Mesh.”
Maarten van der Ploeg of RIWA-Maas: “We compared our critical limit values for water intake with the discharge of water from the Meuse. In the moderate scenarios, too, there is too little water in the summer to exceed these limit values. That is disturbing.”
The lower supply of water in the Meuse coincides with an increasing demand for water, due to various sectors, but also due to population growth in the west of the country. The drinking water companies are now considering measures. “We must try to become less dependent on the Maas water,” says Wim Drossaert, director of Dunea, which supplies drinking water to approximately 1.3 million inhabitants of South Holland. He mentions a “change of course” by, for example, looking for other, additional sources.
It’s not that simple; the groundwater in the west of the Netherlands is saline and it is ‘technically quite complicated’ to desalinate it. “It takes time.”
Searching for suitable surface water elsewhere, perhaps another river, also takes time, partly to obtain permits – and it requires major investments. Another alternative is saving on water. Drossaert: „We are campaigning to urge the public to be frugal, for example not to water your garden in the summer. We are also in talks with companies. We will certainly continue to do that, but it is all a long road.”
The fact that the supply of water falters in the summer months is all the more urgent because in such cases the water quality decreases. Drossaert: “The less water, the greater the chance of contamination. If you continue to discharge into less water, the concentration of that pollution will increase and we can no longer take in the water.” Stocks are limited to delivery for six to eight weeks, says Drossaert. “In the dry summer of 2018, we were really stressed.”
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The drinking water companies are pressing for agreements on restrictions on discharges when there is little water. Drossaert: „That would help us. But it is not settled yet.” Maarten van der Ploeg: “Low discharges are taken into account in discharge permits. But many of those permits are very outdated, and they are still calculating with higher discharges.” In addition, some substances are not licensed, but they are discharged. Van der Ploeg: “There is still a lot of work to be done.”
Drossaert: “People may think that we remove all pollution from the water. But it’s not that simple. We can’t just put in a sieve to get all the PFAS out.”
In a joint statement, the drinking water companies are making an ‘urgent appeal’ for more consultation on the Meuse and its tributaries, at national and international level, between governments, water managers, research institutes and water users. “These discussions should lead to better and tougher agreements in the catchment area about the use of the Meuse water, and to joint measures to reduce pollution caused by industrial discharges, for example.”
A version of this article also appeared in the newspaper of June 24, 2022