Subtractive billing to manage an unexpected water shortage
Suppose your city has an unexpected infrastructure failure that causes a water shortage (such as the one in Winnipeg, Canada in February 2024) and people need to ration water: The city will give an advisory telling people to use as little water as possible. But that relies on people's good nature - what if that's not enough; what if too many people won't ration water unless they have some selfish motive? Then what? It wouldn't be fair to just raise water prices all of a sudden. The customers aren't at fault for the water shortage, after all. That's why I propose a compromise: subtractive billing. How it would work: The water prices are increased, maybe even 5-fold. But every customer is also given a fixed daily credit to cover a basic amount of water that an average person should reasonably need (adjusted to the number of people in the household). So people who use more than that amount will have to pay, and people who use less than that will actually get money back. The credit is calibrated such that the water company does not profit nor loss significantly from this change of billing. When the infrastructure problem gets repaired and the water is no-longer in shortage, billing goes back to normal. For this to legally work, it would have to be codified in the customer contract mentioning the possible scenario - and it would have to be written in a way that wouldn't enable the company to abuse its power. [RESEARCH needed]