I was you. We were paying 90-100 per month roughly. On a meter. They reckoned we were using on average 650 litres per day.
I had them check for leaks. None. I had my meter monitored hourly. There were no anomalies.
We really just were using loads of water. I have 4 children under 7. I was doing loads of washing about 14 loads per week. Bath every night for the kids. Shower for husband and I each morning. Washing up pans leaving tap running, dishwasher on three times a day.
We had to cut back as we changed jobs and had less money. I bought a device on amazon where by it measured my shower usage litres per minute. Mine uses 12 l per minute. We were having ten minute showers every day so that was 240 litres alone each morning. The kids having a deep bath although sharing water was 100 l.
I emailed bosch and found out the cycle I used on my washibg mach used around 60 so another 120 L right there.
Flushing the loo is about 10 L each go so make sure we use the economy flush button now as this adds up too. Got a free bag from water company to put in loo to save water each flush.
What I did: massively cut back on washing I insisted the kids wear things more than once if possible. I will only do one load a day now. I bought a new washing mach too as old one died, the cycle is 50 l.
Kids bath ever other night with a wash on the other days. Bath half full. If I don't need a shower some days I can get away with a good wash and clean clothes if I'm in a hurry.
Otherwise I do shower each day but have a timer set for 2 mins. Dh does tge same. Only days it's longer is when I need to wash hair. The its 4 mins.
Turn off taps when washing up.
By doing this we now use 320 l per day way under what is usual for a family of 6 and my bill is half what it was. I started this in january anf apart from the longer shower I don't miss any of the other bits.
I say carefully examine your usage as it does add up. I didn't believe it but it does.