This is our core business - water meters (at least in the UK) generally don't have any kind of transmitting or external capability. What they do have is an option to add a sensor that detects the 'rotation' of the meter and provide a pulse output - depending on meter type, each pulse represents a specific number of litres - the handheld test unit we manufacture can be set from 0.5L per pulse to 1000L per pulse (the last was added on request, and is obviously a
VERY large meter on a water main).
From the sensor various items can be connected, including loggers (which transmit the meter reading to a central location, most use SMS, mine use GPRS), BMS's (Business Management Systems), and local readers - a device mounted up on the wall, which the water guy reads using a handheld reader, presumably RFID of BT etc, very short range anyway. As the sensors are only single units, to connect multiple device requires splitters, which we manufacture and is a large part of our business.
As far as I'm aware there no 'people driving round in vans, sitting there and reading meters wirelessly' in the UK, it's either done manually, via a device that you have to essentially touch, or remotely with no human intervention at all (I have a number of loggers due to come in shortly this morning, from deepest darkest Scotland
)
So it really depends on exactly what the OP has, he would need to examine his meter and anything attached to it.