Aquifer

An aquifer was an underground river. Aquifers ran under the "southern plate-steppes" of Cartago. (PROSE: The Bloodletters)
On the planet Maught, where water was scarce, rumours circulated about an underground river which the Tenth Doctor eventually brought up to the planet's surface. (COMIC: The Green, the Bad and the Ugly)
Category:Geologic features
Category:Rivers
Category:Bodies of water