[1] Hydrological springs are naturally occurring places where water flows from the aquifer (underground) to the surface.[7] Springs are identified by type: river rise (RR) is where a river emerges after flowing underground for a distance; a single spring (SS) has one underground source, but may flow through multiple rock fissures; a group spring (GS) has multiple underground sources; a sink (SK) is an opening in the Earth's surface that occurs from karst processes[8] and/or suffosion.[9] Volume values listed are the most recent found, mostly after 2000, but water outflows have diminished significantly since the 1990s with drought conditions and increased pumping from the Floridan aquifer.Following U.S. Supreme Court rulings, the Federal Register published EPA's final definition on November 26, 2008.Section (3) states: "intrastate lakes, rivers, and streams which are utilized by interstate travelers for recreational or other purposes (are navigable waters).