Is it possible that your water meter has a “remote read” capability? My water meter is “analog” (physical wheels that go round) and is in the middle of a field with no electricity supply, but the meter-reading person reads it while simply driving past in a van. They don’t get out of the van and I don’t suppose they know exactly where the meter is.
Water companies have a programme of replacing older meters by these “AMR” devices as it saves them money. EG Water meters - help and advice
It has occasionally occurred to me to see if I could acquire and/or make a reader that could emulate this and feed it into my Emon system, but I haven’t progressed this idea. I’d be interested if anyone else has tried it.
(I haven’t looked into it, but I think the energy needed to perform the meter reading comes entirely from the reading device via RF waves; I don’t think the meter itself has a battery but I could be wrong.)