there must be something in the water

Said when something occurs multiple times or presents itself among numerous people within the same area. Implies humorously that something in the drinking water of some area is causing people to show a particular characteristic or act in a certain way. A group of local teens have started something of a trend, as more and more high school students begin spending their spare time volunteering around the county. There must be something in the water. There must be something in the water down here, because this is the third time in the last eight months that someone from this town has won the national lotto jackpot.