Why does wealth affect water consumption

sustainability

Water is life - this insight has been shared by peoples around the world for thousands of years. At first glance, carelessness seems to be justified, because more than two thirds of the earth is covered by water. And even if you subtract the salty sea water and the fresh water that is not available for human consumption, such as the polar ice masses, 12,000 cubic kilometers of drinking water remain. There seems to be more than enough for everyone, especially in rainy countries like Germany. Nevertheless, environmentalists urge us to handle the precious water carefully. An exaggerated requirement? Many people in Germany consciously save water, for example with the help of economy buttons on toilets. At the same time, however, we are also experiencing waste and the inconsiderate discharge of pollutants in this country. Sustainable use of water is not only hindered by a lack of awareness and a short-term interest in using it, but also by the complexity of the processes involved in the "consumption" of water.

Is there no need to save water?

The Germans are considered "world champions" when it comes to saving water. The local drinking water consumption is extremely low at around 120 liters per inhabitant per day [1], which has been a success of long-term campaigns. At the beginning of the 1990s, German per capita consumption was still 145 liters, and in the USA and Japan it is still significantly more than twice as high as ours. However, there are increasing doubts as to whether it makes sense to save water in Germany. The amount of water available in our own country seems to be more than sufficient, and our water conservation is apparently irrelevant to remedying water scarcity in distant countries. Some experts in water management even warn against excessive savings efforts because the water and sewerage network is designed for larger quantities and the flow rate, especially of the sewage, could become so low that there is a risk of blockages.

However, no one has yet been able to reliably predict the consequences of climate change. This applies, for example, to the consequences of the gradual melting of the Alpine glaciers. So far, they have been binding large amounts of water in the form of ice and snow in winter, while meltwater is continuously released into rivers in summer. The glaciers therefore have a balancing function for streams and rivers. If this buffer is omitted, heavy rainfall in the mountains can lead to increased flood disasters on the lower reaches of the rivers and - mostly in the summer months - to longer periods of low water. This has an impact on the formation of groundwater in zones near the shore. It should also be taken into account that the pollution in many near-surface aquifers is increasing, especially through industrial soil pollution as well as nitrates and pesticides from agriculture. It is therefore advisable to conserve the lower-lying groundwater reserves. In addition, too little attention is paid to the close connection between water and energy consumption. In this country, the number of "warm showerers" is considerable, and the water is warmed or heated for many other purposes before it is used. The area bathing / showering / personal care offers a particularly large savings potential in domestic water consumption, because 36 percent of drinking water is used for this. Flushing the toilet accounts for 27 percent of consumption. [2] Water-saving fittings help with careful use and are now standard in most new buildings. Saving water serves to sustainably store this indispensable foodstuff and also helps to reduce costs. Such consumption behavior can then also form the basis for gradually adapting the line networks to the reduced consumption.

In many developing countries, on the other hand, the water situation is dramatic: a growing number of countries are suffering from water stress, and one consequence of this is that internal societal conflicts over the rare commodity are increasing, in Africa above all between arable farmers and migrant ranchers. Tensions about the water distribution of cross-border waters are also growing, for example among the eleven countries bordering the Nile and its tributaries. Even so, water waste is still significant in many developing countries, largely due to the fact that a third or even nearly half of tap water is lost to leaks before it reaches customers. In the meantime, attempts are being made in many cities in the south of the world to drastically reduce these losses by renewing the line networks. Fortunately, water-saving techniques are increasingly being used in taps and toilets in countries with water stress. It would send the wrong signal if the "water-saving model" Germany were to stop its own efforts in this situation.

"Virtual" water consumption

4,000 liters of water a day - this is the average "virtual" water consumption of every German citizen. "Virtual" is the amount of water that is required to produce all the goods that we consume every day. For example, more than 15,000 liters of water are required to produce one kilogram of beef. This includes the water that the cattle drink in the course of their life, the water that is required for the production of the feed and (a smaller item) the consumption of the slaughterhouse. One kilogram of corn has a "water footprint" of 900 liters, a cup of coffee of 140 liters, a pair of jeans of 11,000 liters and a car of 400,000 liters. [3]

The virtual water requirement has meanwhile been calculated for many products, whereby a large number of factors have to be taken into account in the evaluation. For example, it makes a difference whether the tea is grown in a very rainy region like Assam at the foot of the Himalayas or in countries with water stress. It also depends on whether the water is returned to nature after use, heavily polluted, such as by many Indian dye works, or whether it contains hardly any pollutants as in organic rice cultivation. Nevertheless, it is possible to consider how much virtual water we use when we consume it ourselves. Martin Geiger, water expert at the nature conservation organization WWF, emphasizes: "How much virtual water there is in a product cannot of course be seen at first glance. The rule of thumb, however, can be: buy regionally and seasonally, only consume meat in moderation. That alone you can save quite a bit of virtual water. "[4]