The Dutch government on Wednesday declared a water shortage, following an unusually dry summer with no rain forecast for the coming two weeks.
Brutal heatwaves gripped large parts of Europe and the United States last month, bringing about calls for more efforts to tackle global warming, which scientists say makes spells of extremely hot weather more frequent and deadly.
With two-thirds of the Dutch population living below sea level, droughts can quickly become an acute problem in the Netherlands, leading to rivers silting up and hampering water traffic.
A further problem arises from dikes drying out - many require the weight of water itself to remain strong.
"We have been seeing it get drier in the Netherlands for several weeks now because of evaporation in our own country and very low river flows from abroad," said Michele Blom of the country's Public Works and Water Management agency, appointed to oversee a drought task-force.
At the moment, barges on the lower Rhine - an important route for transporting coal from Rotterdam inland to German steelmakers and power producers - are operating at less than half capacity.
The Dutch ministry of infrastructure and transportation said that as of Tuesday, water was flowing through the Rhine at 850 cubic meters per second at Lobith, the eastern town where it enters the Netherlands, "exceptionally low for the time of year."
Levels were better in the Maas, also known as the Meuse, which flows from France into the Netherlands.
The IJselmeer, a large artificial freshwater lake in the north of the country that was carved out from the North Sea in the 20th century, is reasonably filled and can supply water to the province of Groningen.
However, groundwater levels are sinking and "are very low in places in the south," the ministry said, leading to algae blooms and fish death.
Drinking water is not affected.
Water districts are calling for people to conserve water, with southern provinces of Zeeland and Limburg asking people not to use surface water for watering -- a measure that affects farmers.
(Reporting by Toby Sterling and Stephanie van den Berg; Editing by Tomasz Janowski)
