why is it so that people must pay more if they use more water

Charging higher rates for excessive water usage is usually implemented as a way to promote conservation and ensure that there is enough water available for everyone. By charging higher rates for higher water usage, it incentivizes individuals to be more conscious of their water consumption and encourages them to use water more efficiently. This can help in reducing water waste, particularly in areas facing water scarcity or drought conditions. Additionally, the revenue generated from higher water usage charges can be used to invest in improving water infrastructure and conservation efforts.