Water Rates - possible issue

Other

I purchased my second rental property last year. An end terrance split into flats and bedsits. I had a Council Tax bill - Band C - for the whole property and a Water Rate bill - the same. The property was converted into its present use at least 30 years ago, either by the person who I bought from or the owner before - no-one got planning or buliding regs - a separate issue, which I will be dealing with.

I had a phone call yesterday from the Council as they had become aware that the basement flat is self-contained (as are the other two flats, the bedsits share a bathroom and additional toilet). They asked about the property - how many self-contained flats there were and said that they would have to contact the District Valuer about re-valuing the property. This is manageable - I will simply have to reassess the rents, once the figures are clear.

My concern is what to do about the water rates. The plumbing within the building is all inter-linked - there is only one stopcock as this was built as an Edwardian family home originally. Any attempt to fit separate meters to the three flats and the remainder of the building would involve moving lots of pipes, potentially messing up a lot of refurbishement done duirng the last 12 months to bring the property up to standard.

Does anyone have any ideas please?