Few people know about the underground world that exists beneath Bowling Green, where water can flow in underground rivers in what is known as a karst landscape. In karst areas, water is especially vulnerable to pollution because everything on the surface can quickly make its way underground. In fact, even our drinking water is vulnerable to pollution because of our karst landscape. This is possible because a portion of the water feeding the Barren River, from where the City draws its drinking water, flows through underground karst networks before it resurfaces at springs along the River’s banks. Other water in the river comes from stormwater runoff flowing along the surface.