I am shocking to learn this fact. I hope the data are indeed “residential” water usage, not including agriculture usage, because the western states have a lot of agriculture land.
A national survey on water use in the U.S. showed that residents in states that get less precipitation use a lot of water in their homes — western states use an average of 137 gallons per capita every day, compared to 82 gallons in the mid-west. According to the Environmental Protection Agency, this is mostly because of the higher amount of landscape irrigation in the west. In other words, people striving for green lawns and lush plants in dry states have to water more often that people in places with lots of rain, or risk fines in some communities.
Reference: The Most Water-Consuming States Are The Ones In Drought