Water Knowledge

Interesting facts about all aspects of water, what you can do to protect the vital resource for future generations too.

A little water science

Imagine this: there are four glasses on a table. Each one has a different type of water in it: mineral water, table water, curative water, and drinking water from the tap.

Admittedly, at first glance you could probably only tell the difference between the still and the sparking water. And even though the taste of each provides some indication of the mineral content, it tells you nothing about the origin and the type of water. In fact, each of them has its own special properties. Reason enough to examine the four glasses and their contents more closely.

Water requirements of the body

About two-thirds of the human body is water. This proportion must be kept constant so that we feel good. This means that we each need take in 2 to 2.5 litres of water each day. On hot days or if you’re doing sport, your water needs can rise by a factor of three to four. Under normal conditions, we lose about 0.5 litres of water daily just by perspiration through the skin alone. The same applies to breathing. We also excrete approximately 1.5 litres of urine through the kidneys.

Find out why water is so important for us humans and what happens if we do not permanently adjust our water balance.

Virtual water

Apart from the direct use of water, on average, each German needs a further 4,000 litres of so-called virtual water. This water comes from other countries and is used for the production of meat, fruit, clothing or to provide services.

An example:

Anyone who wants to eat strawberries or asparagus out of season makes use, for example, of imports from Southern Spain, Morocco or Peru. These regions suffer from a shortage of water. Watering the enormous strawberry and asparagus fields – including with water from illegally drilled wells – causes the groundwater table to fall even further. A vicious circle.

Our tip: Make use of home-produced products. By purchasing regional seasonal goods you reduce your indirect water consumption. This is also easy on the environment and protects water as a resource. Worldwide. Immense quantities of virtual water are also used in the production of textiles - particularly those made of cotton.

Virtual water on klassewasser.de

Dosing cleaning agents correctly

It is important to dose cleaning products correctly to protect our environment. We give you a few tips on what you should pay attention to.

What does not belong in the toilet

We use water to cook, shower, to water flowers and, of course, to drink. Waste that is thrown away in the WC causes disruptions in the sewers and faults in our wastewater treatment plants. Solid waste, food leftovers, medicines, paint residues, solvents and other chemicals therefore do not belong in the toilet. Once they are in the water, pollutants are difficult to remove. Help to protect your water!



Cosmetics, clothing or car tyres - many everyday items and products contain or cause microplastics and therefore impact the environment. Berlin’s drinking water is free from microplastics, yet microplastic particles are increasingly detectable in  the wastewater. Each person must therefore be called upon to prevent inputs of microplastics in wastewater. We explain this topic to you on our service page.

More about microplastics

Avoiding trace substances

Did you know that water in Berlin is managed in a cycle? This functions almost naturally when we treat groundwater without chemical additives and distribute it in the city through our pipes. We take back the used water, pipe it through sewers into the wastewater treatment plant and after treating it we return it to nature. The greatest challenge lies in also filtering out the invisible pollutants. This is because, wittingly and unwittingly, humans leave behind many microscopically small traces which can only be removed by complex processes.