In Oslo, 35 per cent of the clean drinking water is lost on the way from waterworks to tap. The large volumes of drinking water seep out from leaks in the pipe network, and until now, focus on water losses in Norway has been limited.

But now the municipality of Oslo, which is responsible for the water supply in the Norwegian capital, has articulated an ambitious plan to reduce water losses and secure the future supply of clean drinking water to Oslo.

Until 2022 the city of Oslo will execute a five-stage plan to reduce leakage. The plan includes introducing a standardised method to calculate water losses, to divide the pipe network into smaller areas, to control and optimise pressure in the pipe network and to strengthen analysis and reporting of key performance indicators.

The goal is to bring the leakage level in Oslo down to 20 per cent by 2030. Furthermore, a key component in this five-stage plan is to establish an advanced online model of the entire supply network, which comprises 1,550 kilometres of water pipes. It will provide the supply company with a real-time overview of the water’s flow through the drinking water system and the pressure level in the pipes. This will amongst others allow the city of Oslo to identify leaks early on by looking at water volumes, flow directions and variations in water pressure.

Water challenge

Oslo is a city in growth. At present, approximately 700,000 citizens must be provided with clean drinking water. However, in the future, the city expects to supply water to as many as 900,000 inhabitants.

This means that there is a need to rethink the strategy in order to secure the capital’s future drinking water supply. Part of the answer is to reduce the amount of drinking water that is lost due to leakage. This will save approximately 35 million cubic metres of water every year – or slightly more than a third of the city’s current water requirements.

As a consultant to the municipality of Oslo, NIRAS is implementing an online model, the Aquis system, which will cover all of the supply network’s water pipes. In addition to Aquis, the management information system HOMIS, which is developed by NIRAS, will be implemented. When the basic system is configured, the team of consultants will train the Norwegian technicians, so they themselves will be able to operate the system and monitor possible leaks in the pipes and not lose precious quantities of clean drinking water.