I contacted my water company a couple of years ago to see what they did for people with BI who are on benefits.
My water company is Dwr Cymru/ Welsh Water.
I was not on a water meter.
They have a unit that deal with people with disabilities/illnesses/etc that are on benefits.
Not only did they lower my bill dramatically they also added me to their vulnerability list. This means if there was a problem with the water supply/ sewers etc you are on a priority list and will be delivered bottled water. I'm not sure if it means you also get priority maintenance to the pipes leading to and leaving your property though.
It's worth contacting your water company to find out if you can get a reduction in bills or get some other kind of service.
There is however a very big difference between Welsh Water and all the other water companies outside of Wales.
Welsh Water is a not-for-profit company and has no shareholders, whereas all the others are owned by shareholders and this may make a difference.