Gutermann: Sensor Technology and IoT Prevent Water Loss

Water is an increasingly valuable resource. Yet some of it is lost due to defective water pipes. How a Gutermann and Telekom solution helps to detect and locate leaks fast.

The public water supply system records enormous worldwide water losses every year. Large quantities of the valuable resource seep into the ground before they can flow from the faucet and reach the consumer. How high the water losses are in individual countries and regions varies. According to 2020 figures published by Germany’s Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU), losses in the German drinking water supply network amount to up to ten percent. “In discussions with customers, however, individual suppliers or local authorities complain about higher losses of more than 20 percent. That depends mainly on the age and condition of the water network, which in turn is strongly influenced by climatic conditions,” says Uri Gutermann, CEO of Gutermann, a Swiss company that specializes in leakage detection in water infrastructures.

Material fatigue, high water pressure, environmental events or construction work in which water pipes are damaged cause leaks or burst pipes. Water then escapes, frequently unnoticed for longer periods with partially devastating results. “Possible damage to water pipes, surrounding infrastructures and the environment can be very serious in a short time,” Gutermann says. There is also the water that is lost. So leaks must be detected and repaired as soon as possible. “Without special methods and professional leakage detection applications, however, the cost of finding leaks, especially in very large water mains, is very high,” he notes.

That is why his company uses a special acoustic leak detection process.  So-called loggers record noise profiles along the water supply network. Depending on pipe diameter and material, the tiny sensor modules adhere magnetically to the metal pipes or are attached to the shutoff valves at intervals of between 50 and 600 meters. They are equipped with sensors and an NB-IoT wireless module with a SIM card. The sensors measure acoustic signals daily in the water and the pipe and the modules send the digital data straight to the cloud via the cell network for analysis. Gutermann makes use of correlation. All sensors measure noise at the same time. The noises are analyzed and the profiles of adjacent sensors are compared. Ambient noise such as that of road traffic is filtered out.

“The sound of a leak between adjacent sensors has exactly the same profile, so we can identify it as a leakage point,” Gutermann says. The site of a leak can be established accurately to within a meter by means of parameters such as distance between sensors, materials, water pipe diameter and the speed of sound. Analyses are sent via an encrypted connection to the waterworks on a Google Maps browser interface. The waterworks can then embark on the necessary repairs with no further significant location expense and without digging up large sections of road.

To connect the loggers with the cloud, Gutermann relies on NarrowBand IoT (NB-IoT) and on cooperation with Deutsche Telekom. Thanks to its high level of building penetration the mobile communications standard transmits data reliably even from underground water pipe shafts. Gutermann can fit out the NB-IoT modules with preprogrammed noise loggers and batteries. Attached on-site in minutes, they are ready to run.

That was not always the case. In the past Gutermann used other standards that lacked the signal strength required to transmit the measurement data. So they installed additional overground data gateways. “We attached the modules to lamp posts or other available infrastructures. Our customers often had to apply for permits to install them and we sometimes had to provide a crane to assemble them. That all cost a whole lot of time, labor and money,” Gutermann says.

With NB-IoT the company no longer needs a second device or to maintain the network that involves. “The NB-IoT solution’s scalability is its decisive advantage. Costs per measurement point are lower, we need only one device and no repeaters, and we have no assembly costs. That has made rolling out our solution on a large scale markedly more economical. And thanks to the international availability of NB-IoT in Telekom networks we can undertake projects all over the world.”

Take Italy, for example, where Gutermann and Telekom are fitting out the main pipelines of the entire Acquedotto Pugliese (AQP) network with noise loggers. For the water supplier in southern Italy’s Apulia region they are installing 20,000 measurement points: “the largest acoustic leak detection project yet in continental Europe,” Gutermann says.