Recently, a NASA-funded study, which used satellite data collected by the Department of Defense, determined that, including golf courses, lawns in the United States cover nearly fifty thousand square miles—an area roughly the size of New York State. The same study concluded that most of this New York State-size lawn was growing in places where turfgrass should never have been planted. In order to keep all the lawns in the country well irrigated, the author of the study calculated, it would take an astonishing two hundred gallons of water per person, per day. According to a separate estimate, by the Environmental Protection Agency, nearly a third of all residential water use in the United States currently goes toward landscaping.
Source: Elizabeth Kolbert, New Yorker