Preventing water loss

Danish water utilities are among the best in the world at limiting water loss. Learn about the technologies and methods they use to monitor the pipeline grid, plan pipeline repairs, and identify and repair leaks quickly.

What is water loss?

Water loss is the amount of distributed drinking water that does not reach customers, and that water utilities therefore do not receive payment for. This is also known as non-revenue water (NRW). 

NRW covers:

  • the amount of water lost due to e.g. ruptures and leaks in the pipeline grid and reservoir overflows (also knows as physical losses)
  • unauthorised consumption, such as illegal tapping and meter inaccuracies (also known as apparent losses)
  • authorised consumption used to flush pipes at new installations and during repairs, water used for fire fighting and sprinkler systems checks, etc. (also known as unbilled authorised consumption)

Water loss is often either calculated as the percentage og total distribution or as cubic meters per network kilometre per annum. 

Denmark has implemented systematic measures to reduce the loss of drinking water as it makes its way from waterworks to the consumer. Danish drinking water providers are actually among the best in the world in this area.

Water loss is a waste of resources

Water loss in Denmark is 7.8 per cent on average. In comparison, many countries lose as much as 30 to 60 per cent of their treated water before it reaches customers. This is not only an enormous waste of clean water, it is also a waste of the resources that have been used to extract the water, treat it and distribute it.

One of the reasons why Denmark is so good at keeping drinking water in the pipeline grid is that providers use new technologies, methods and knowledge. This makes it possible to measure and register water data and to quickly identify even the smallest pipeline leaks.

Another reason is that, since 1994, waterworks with a water loss of more than 10 per cent have been required to pay a penalty fee to the state. Furthermore, since 1996, all properties connected to public water utilities have been required to install water meters. This has resulted in significantly more reliable data on which to base efforts to reduce water loss.

This website provides an description of a number of these methods and technologies. Additionally, there are examples of three water utilities that have succeeded in reducing water loss significantly over the past few years by applying a systematic approach to the issue.

Danish Water Sector Reform Act

The Danish water sector is regulated by the Danish Water Sector Reform Act. This act covers municipal water and wastewater as well as private waterworks that sell more than 200.000 cubic meters of water per year. 

The act requires drinking water and wastewater utilites to collect specific performance parameters, including water loss. 

There are many good reasons to reduce water loss

Since 1994, water utilities in Denmark have paid a penalty fee for any loss of water that exceeds 10 per cent of their total distribution.

This in itself has provided a financial incentive for water utilities to launch efforts to reduce water loss.

Even though a water utility has a water loss of less than 10 per cent, there are still important reasons to limit water loss even more:

  • Water loss is a waste of resources. The loss of drinking water in the pipeline grid is not just a waste of good water. It is also a waste of the energy that was used to produce the drinking water.
  • Better exploitation of groundwater. Pipeline water loss is an unnecessary waste of groundwater resources, which every year cost considerable sums to protect.
  • Risk of contamination. In some areas, water loss will seep back into groundwater aquifers. However, there is a risk that the water will become contaminated underway or end up in a groundwater aquifer that is not used for drinking water.
  • Drinking water leaks into the sewer system. Some of the water loss will leak into sewers or directly into a surface water recipient, which means the water can no longer be used as drinking water. This is particularly serious in areas where the groundwater resource is vulnerable.
  • Image and corporate social responsibility. Water utilities can demonstrate their corporate social responsibility by working proactively with water loss. Their initiatives and results can be reported and referenced in their CSR reports.

Overview of methods and technologies

For more information

You are welcome to contact the organisations below if you would like to know more about specific technologies. They can also help you identify the appropriate advisors and suppliers.

DANVA - stakeholder organisation for drinking water and wastewater utilities as well as all professionals in the field of water and wastewater.

Danish Environmental Technology Association - the sector association for Danish environmental technology companies.

Danske Vandværker - the sector association for Denmark's waterworks.

Case - three examples