LoRaWAN transmits only small amounts of data. For example, the researchers installed a sensor at an overflow, which transmits the information “wet” or “dry”. Consequently, the devices use very little energy. The gateways use solar power, and the production and maintenance costs of the battery-powered sensors are low. Nevertheless, LoRaWAN has a range of over 20 kilometres. This summer, exceptionally favourable conditions meant that a networked gateway near Aarau received information about precipitation in Fehraltorf, 56 kilometres away. According to Christian Ebi, who works with various Eawag departments as a technician, the new technology even allows remote mountain valleys to be connected to the LoRaWAN network at low cost. The primary concern of the researchers, however, is not the establishment of new infrastructure, but the optimal operation and maintenance of existing drainage networks. Their vision is a “glass city”: in order to minimise risks of flooding and water pollution, for example, it is vital to understand the hitherto invisible wastewater infrastructure and to shed light on what goes on underground. To this end, Eawag is working with Zurich University of Applied Sciences and the University of Applied Sciences Rapperswil to develop sensor technology and expand the network. It is also planned to install sensors directly in groundwater and waterbodies.
Close cooperation between research and practice
Thanks to the collaborative project between Eawag, ETH and the municipality of Fehraltorf, prospective environmental engineers are afforded insights into the development and operation of the field laboratory, and can answer real-world questions using the latest analytical methods. The extent to which the field of water protection can be further improved remains to be seen, but one thing is already certain: the project promotes an active exchange of ideas between science, tertiary education and partners working in the environmental sector.