Watering the Lawn?

Jon and I went for a walk after dinner, which was something Elder Kikuchi had said in Stake Conference that married couple should do. As we were walking through a neighborhood in Maumee, we saw something that was a little weird. First I should say that not many Ohioans water their lawns. Most of the time there is enough rain that it is not needed. Recently, we have not gotten much rain and lawns around town look really sad. It's almost like home.

Anyway, we were walking down the street and there was a guy putting out a sprinkler to water his lawn. He placed it right in the middle of the sidewalk. That way it watered the grass between the sidewalk and the road and the grass in front of his house. He's a multitasker. It was just a little weird to see him put a sprinkler on the sidewalk and leave it. Does the side walk need water?