Going back to the 'save water' comments - the concept that we should ever be short of water in the UK is just utterly ridiculous.
We live on a wet little island, in the a wet corner, just off the coast of the wettest continental area in the northern hemisphere.
Domestic water supplies shouldn't be metered, ever, in the UK.
It's just a money grabbing exercise by the water supply companies - whose inadequate planning, pawky maintenance and reluctance to invest in the supply network are inventing a problem for 'metering' to solve - whilst lining the pockets of their foreign owners at our expense.
In the 21st century in the UK no-one should be thinking about the cost of keeping clean or (worse) not flushing the toilet to save a few pee ...