Few of us ever really think about what our drinking water costs. If we do, it’s usually because we’re a homeowner looking at the water bill. And if we rent, water costs are often hidden inside a flat utility fee. Whether owner or tenant: Most people don’t actually know how much they pay for water in a month.

In a survey, less than 20% of those responding had an idea of their monthly water costs. This suggests one thing above all others: Water is relatively inexpensive - enough so that for many, it does not really register in our wallets. But how is the price of water calculated in the first place?  What does a cubic meter of tap water cost across Europe? And, above all: What can we expect in the future?  Here are some answers to these questions.

The price of drinking water varies wildly across Europe. At the one extreme, tap water is essentially free in Ireland - as long as there is no excessive use. It’s most expensive in Denmark, where households pay over €9 per cubic meter on average. Yet that still comes out to less than a cent per litre. The average water use itself ranges from 77 litres per person per day in Malta to nearly three times that (223 litres) in Italy. Relatively speaking, drinking water revenues are highest in Germany, at around €155 per person per year. But what makes up the price of drinking water?

After all, in most places, water is currently simply available - sometimes abundantly. As a renewable natural resource, it’s practically free. The exceptions are Cyprus and Malta, which draw more than half their drinking water from desalination plants. But as the example of desalination plants shows, it takes infrastructure to bring water from the source to your tap. Generally speaking, the steps are extraction, treatment, and distribution.

For all this, infrastructure has to be built, operated, and maintained. In energy alone, delivering a cubic metre of water consumes 0.33 kWh of electricity on average - enough to brew 20 cups of coffee. And that’s not the end of water costs - once used, water turns into sewage that has to be treated again. Next, we’ll look at these steps in more detail, starting at the source.

Once purified, the drinking water has to be piped where we actually need it. This requires a well-designed system of storage tanks, pumps, valves, and an enormous number of pipes. These range from huge pipe mains to relatively small connection lines to individual buildings.

Again, all of this requires construction work. And though pipes typically last for decades, they do require maintenance and eventually have to be replaced. If you have ever witnessed a burst pipe - perhaps even in your own house - you know why keeping the water distribution network in top shape is so important. Today, water suppliers use sophisticated equipment to spot water losses as quickly as possible.
 

Wastewater treatment

Of course, the journey of water doesn’t end when you open a tap or turn on the shower. Though we actually drink very little of our drinking water, nearly all of it eventually ends up in wastewater treatment plants - other than what evaporates after watering your plants. A significant share of drinking water is never used at all: from broken or leaky pipes, it seeps almost straight into the sewers or the ground.

As we’ve just seen, a lot of work and infrastructure is required before clean drinking water can flow from the tap. The price of water thus reflects the cost of building and maintaining extraction and treatment plants, pumping stations, and endless lengths of piping.

The European water suppliers operate around 4.3 million kilometers of pipe - some 11 times the distance to the moon. The result of their labour is that practically all Europeans have access to safely managed drinking water.However, the complexity - and the age - of the European water supply networks also has drawbacks. These millions of kilometres of pipes also need a lot of maintenance and, eventually, replacement, and delaying the necessary investments is ultimately a losing game, as water loss rises and repairs become ever more urgent - and costly.

At the same time, another challenge awaits water suppliers and every one of us: climate change.

How well will Europe’s water supply systems deal with an uncertain future? Given rising temperatures and increasingly extreme weather, some doubt is only natural. After all, droughts and heat mean less rain and more evaporation. This lowers river water levels, which leads to a sinking groundwater table in their vicinity. Finally, this means that less groundwater replenishes the reserves underground.

And, of course, we all use more water when temperatures rise - less for drinking and cooling off than to irrigate lawns and, more importantly, crops. Agriculture already accounts for half of all water used in Europe, though only 9% of the agricultural area is being irrigated right now. For example, parts of Southern Europe - such as in Greece or Spain - are already water-stressed, and there is growing competition between agriculture, households, and the industry where supplies are short. In the long term, the potential for friction between regions is increasing. In some European countries, water demand will rise simply because the population is growing.

One thing is clear, however: The costs of water infrastructure will rise. Higher demand means expanding water extraction and treatment plants and constructing new ones, a larger supply network, and - particularly in the rapidly growing cities - for wastewater treatment. At the same time, the existing infrastructure is aging. To keep down losses of ever more precious water, the European countries will have to increase the pace of modernization significantly. In short, higher investment and higher demand will mean that drinking water prices will grow higher in the face of climate change - though not at the same rate in all places.

At the moment, however, most of us are still lucky. There is ready access to clean drinking water, and Europe’s water reserves are fairly rich in most parts.  Despite ambitious UN goals to provide this access to all of humanity by 2030, a quarter of humanity still lacks this basic necessity. One reason for this is that in many regions - such as sub-Saharan Africa - water is simply scarce. Where water supply networks exist, losses due to leaks or illegal tapping are often enormous. Often, pipes are so corroded that the quality of the remaining water decreases. The highest water losses are recorded in the Pacific islands, where over 200 litres per person disappear every day before ever making it to a tap.

One thing is clear: Even if we live in countries with large water reserves, we need to keep an eye on how much water we use. This is not just because of higher water bills, but because water is generally becoming more scarce. And water is life.