Creating a wireless water level indicator and/ or controller
An Arduino would fit the bill here except for the difficulty and also expense of adding WiFi connectivity to it.  Wifi &quot;hats&quot; are fairly expensive.
Let me suggest that a Raspberry Pi Zero W is probably the easiest way to make your own IoT device that will keep track of your water level and give you an easy way to check on it or send an alarm.
Here is an example project:
Pi Water Level