The system uses a series of networked, ultra-sonic water-level sensors that are installed in the tanks of water delivery trucks as well as static water tanks in refugee settlements to provide real-time data on water deliveries and consumption. It is based on the “Internet of Things” – physical objects fitted with sensors in order to connect and exchange data over the Internet.

The devices, which cost around 50 euros each, send their readings to a central gateway similar to a mobile phone mast. The gateways have a range of 30 kilometres and can collate data from up to 20,000 individual sensors, meaning a single gateway can cover all the water tanks and trucks serving an entire refugee settlement.

The data is then fed to an online dashboard which gathers information from all the active gateways in a country or region, allowing Githiri and colleagues to see in real time how much water is being delivered and consumed across the entire country.

Read more: Sierra Leone Times