When we moved into our one-bedroomed bungalow it was in council tax Band B, but we complained and they decided we should pay Band A charges. However the water company won’t cut our water bills even though we’re paying less council tax. They told us to get a water meter if we don’t agree with our water rates.
Water bills are still based on the old local government rateable value system in use prior to the introduction of the Community Charge in 1990 so it makes no difference to your water rates which council tax band you’re in. If you don’t use much water you may be better off, as the water company suggests, having a meter installed.