You might find this link helpful. Https://ir.uiowa.edu/cgi/viewcontent.cgi?article=5286&context=etd
Water density and levels can change with atmospheric pressure and temperature. Installing on a bridge or open river water can have some backwater or wave/turbulence effects. An advantage of ultrasonic level sensor may be less chance of woody debris or sediment fouling that can be an issue in my experience with vented pressure transducer. Unvented transducers need a barometer correction.
Thank you guys your inputs! Mohamed ElSaadani I did actually read some of the IFC articles on the subject including the paper of Kruger et al. 2017. Bridge-mounted river stage sensors (BMRSS). IEEE Access 4: 8948–8966. DOI: 10.1109/ACCESS.2016.2631172 which I found of interest. What I am struggling to find is some sort of review/best practices/reflections based on past experiences of using ultrasonic sensors use in hydrology. In terms of brand I meant the robustness e.g. resistance to the weather, long term deployment..