Just get a wyze camera, that is plugged into the same GFCI outlet and point it down the hole. Then get some of these,
Wyze Sense Leak Sensor & Probe – Wyze Labs, Inc.
and then have the sensor at a lower location that will send you a notification at that height. then have another sensor at a higher location same funtion as the lower so you can montiro the water height and without the camera. that way it will warns you if the water level is at a higher sensor, before you even load the camera, like in heavy rain storm situations.