We switched to a meter about 2 years ago and find our bill has roughly halved. Down from almost £100 a month to £50 most months. We are in the South West with South West Water. We are a little more careful with how we use it but don't go over the top trying to save it and still use the power washer a couple of times a year for a few hours at a time.
I've had another thought about the water meter.
A hydrant is very near my stopcock and every time it is used my water is fouled and I have to run the tap until it is clear - this has taken more than half an hour.
On average the hydrant is used six times a year but it can be for days at a time if there are roadworks or building going on.
Since having a water meter installed , I now pay less than half of my previous amount. At the moment I pay about £15 a month. It's been well worth it in my case.
Thanks, woofgang, I've emailed them. I'm hoping they'll be able to sort the problem out once and for all, especially as new houses are due to be built opposite me and I can see the hydrant being used a lot while that is going on.