Hello @mike,
I am currently working on a very similar project - monitoring of a groundwater level and a independently controlled water pumps. There will be a web interface with information about exact water level in cm (up to 5m) with charted historical values and when the set threshold level will be exceeded an email and SMS will be sent to a set of addresses. All of that accesible via web interface.

If you are interested, please contact me on [email protected]. We can continue in Czech language there.

Have a nice day,