Las Vegas city officials have found that a lot of grass is useless. The plant is never laid on, played on or even stepped on. The grass is only there to look nice. The city in the American state of Nevada is built in a desert. And officials have found that there are 21 square kilometers of useless grass. Now, Las Vegas is trying to become the first place in the country to ban that kind of grass often seen between streets, in housing developments and in office parks. It is estimated that useless grass makes up 40 percent of all the turf in Las Vegas and it needs a lot of water to survive. Grass needs four times more water than dry climate plants like cactus or succulents. By tearing out the grass, the city could reduce yearly water usage by 15 percent.