In our latest water bill I noticed that we are now being charged based on consumption levels: the first 10 cubic meters per month are charged at 2.45Y, then a new tier kicks in at double the price at 4.90Y. Sewage is constant at 1Y per cubic meter.
According to their website, there are additional steps kicking for excess water use: www.kmwater.cn/kmwater/selfservice.jsp?id=73
This seems like a sensible encouragement to save water while keeping the rates for essential consumption affordable.