Our group has developed prototypes of low-cost water level sensors, which are used in a variety of contexts, including:
We use several different technologies depending on the application, including ultrasound, lidar, radar, and pressure transducers. Although they are not aimed for operational use, they are quite robust and reliable. If you are interested in installing them for a research project, then get in touch with Wouter Buytaert.
We aim to provide more technical details on the sensors here soon, so keep an eye on the website if you are interested.