Result!
Good news on the water metering front. Maybe these details will help others.
Mum and Dad now have their water charges billed on a fixed charge, "assessed for a two person household" basis. This new fixed annual charge is very nearly what Dad would have been paying for only 6 months metered water (with no guarantee the total usage wouldn't have increased).
I had to go up the management chain of the water billing service, reaching first the Social Policy manager, then being directed to the water company's Head of Customer Relations (she reports to one of the water company's Directors).
It wasn't until I got up to the Social Policy manager that we were able to start discussing how the company could help individual customers with medical conditions making their use of water excessive. Previously, I was told about company schemes - all means-tested, some benefits dependent - for helping people with income problems to pay for their water. The junior staff genuinely didn't know there was anything that would help.
It was the Head of Customer Relations who came up with the right path for us - a water audit to check for leaks (which might have returned the bill to a sensible level) and the option of this "assessed charge" if the cause of the excess water usage problem was Mum (which it was). She also said water metering could be suspended - even after X years - with a return to charging on a "rateable value" basis ... but this option wouldn't have been anywhere near as good for Mum and Dad as the "assessed charge" route.
Incidentally, Ofwat says it's up to individual water companies to agree specific plans to help specific disabled / unwell customers. Once again, those who have advocates may be able to get help - those who don't, won't. That seems wrong to me.
