Dr Andreas Peter is the Head of Quality Monitoring at the Wasserversorgung Zürich water utility company. As head of the Drinking Water department of the Swiss Federal Office for National Economic Supply, he regularly deals with questions about how to ensure the supply of drinking water in emergencies.
«Switzerland is at risk of drying up.» What do you think when you read these kinds of headlines?
Even just a couple of years ago you would have thought that «water stress» would never be an issue for Switzerland, but 2018 was a wake-up call. Water became scarce in many of the smaller municipalities, but it was certainly not a crisis, as Switzerland had more than enough drinking water. The security of supply is also ensured in the long-term, but we do need to tackle the issue of regional integration.
Isn’t the water supply integrated across Switzerland?
No, in contrast to the supply of electricity, the water supply is an isolated operation in many places. The infrastructure is extremely decentralised. There are around 2500 water suppliers, and practically every municipality has its own supply. This has evolved historically over the past 100 to 150 years. The larger agglomerations have networks that extend beyond municipal boundaries.
Back to water stress: So we don’t have to start saving water?
This is a question that needs to be looked at from different perspectives. Water is a valuable resource that should not be wasted. Thanks to our versatile water resources, we are in the fortunate situation that we do not have to ask people to start saving, as is the case in other European countries. Depending on the region, for example, we can draw on spring, ground or surface water. The infrastructure for the water supply is also designed for a certain level of consumption, so if consumption drops by too much, the water remains standing for too long. This can lead to a reduction in quality, so the water no longer tastes as fresh. If water is not flowing, flushing has to be carried out after a certain amount of time.
How can we manage the water supply and ensure the availability of water?
With regard to ensuring the short-term quantity of supply, we are working on overcapacities in the storage volumes, that is to say the reservoirs, and water extraction. This will allow the daily consumption peaks to be covered even during dry periods. The water reservoirs are monitored in real time. If the level falls below a critical point, pumps are automatically activated, and if they are not, then an alarm is triggered.
The integration effort and expense is manageable.Dr Andreas Peter
And in the long-term?
In the long-term, a forecast is created with the General Water Supply Plan, which incorporates assumptions about population development and water consumption, for example. The water suppliers need to ensure that they can cover the relevant consumption in 25 or 30 years’ time. The necessary infrastructure even has a service life of 50 to 100 years, which makes the water supply a multigenerational project.
Is there a national coordination or control centre for the water supply?
At a national level, the Swiss Federal Office of the Environment is responsible for the protection of water resources, while the Swiss Federal Office for National Economic Supply defines requirements for the drinking water supply in emergencies. Otherwise, it is the cantons, and generally their environment agencies, that are responsible for the water supply. The actual supply mandate is assigned to the municipalities and water utilities.
Doesn’t this decentralised organisation pose the risk that we will take water away from each other?
This was previously the case. The Swiss Federal Office of the Environment is currently recommending water resource management in which the cantons cooperate and coordinate. To prevent uncontrolled development and ensure that the groundwater level does not sink, the respective canton issues licenses for water extraction. Hydrological investigations show us the flow of groundwater, so we know how much can be used, and this ensures that it is not overused.
You previously mentioned that there needs to be increased integration in Switzerland.
Yes, precisely. The canton of Zurich, for example, is planning and already building with this in mind. The aim is to establish a cantonal drinking water association with national connecting lines, but it is likely to take a while before the rural regions reach this point. The pressure will increase if there are more dry years like 2018. The integration effort and expense is manageable, as in many cases it is possible to just dock onto existing supply lines, but some level of development is necessary, since the capacities required to ensure the security of supply do not exist across the board.
What about integration at the international level?
There are a number of associations and interest groups in Europe and around the world. Some are focussed on the water quality, for instance, and others on ensuring that the water resources are secured for coming generations. Switzerland is a role model in this respect. We are constantly receiving visits from experts from other countries wanting to find out how drinking water supply and waste water disposal works in Switzerland. Here, the integration is primarily about exchanging know-how, but also technical equipment and services where this is necessary. I do not think that Switzerland will export water to any significant extent in the future.
Maintaining our high level is a challenge.Dr Andreas Peter
The water supply is a critical infrastructure. What does this mean?
Water is vital, there is no substitute for it, so supply must be ensured. As we can see from other regions around the world, a failure of the water supply quickly leads to a crisis. However, it is not just about providing the necessary quantity, but also about ensuring the legally defined quality requirements for industrial and drinking water.
What kind of crisis scenarios are possible?
Water contamination is one scenario. The Swiss Gas and Water Industry Association issues recommendations on how to prepare and respond appropriately in case of contamination, but we assume, for example, that our water supply is not susceptible to deliberate contamination. The large volume of water in the system means that the level of dilution is huge. Besides this, only a small amount of the 150 litres consumed by every person each day is actually drunk. Most water is literally flushed down the toilet. A more pressing issue is cyber-attacks on the municipal control centres. The water supply as well is largely digitalised. We have invested quite heavily over the past few years, so we are in a good position.
How would you summarise the challenges for the water supply?
Maintaining our high level is a challenge. In Switzerland we are fortunate that we have a well-established infrastructure and sufficient water, but we are benefiting from the work done over previous decades and this is risky. We must seize the moment to tackle issues such as climate change, conflicts over utilisation and digitalisation. The demands on the operational activities relating to the water supply have risen sharply. Responsibility for the water supply is often just seen as a side job for the municipalities, so it needs to become more professional and further training and development are needed to meet the quality requirements. All of this compels us to join forces.
Facts on the water supply
- Water utility companies provide 1 billion m3 of drinking water each year.
- 36% of our drinking water comes from spring water, 43% from groundwater and 21% from surface water (lakes, rivers).
- 887 million francs are invested in maintaining the infrastructure every year.
- The water supply distribution grid consists of 90,116 km of pipelines. This is more than two times the circumference of the Earth.
- Almost 55% of the water consumed in a private household is used for the shower, bath and toilet.
- Breakdown of water use:
- Households and small businesses 54.4%
- Trade and industry 25.3%
- Public purposes and fountains 4.9%
- Own consumption 2.2%
- Losses 13.0%