The Tajo River Basin Authority (or "Confederación Hidrográfica del Tajo: CHT") is a Spanish River Basin Organisation. It is an entity with its own law jurisdiction, affiliated with administrative effects to the Spanish Ministry of Agriculture, Food and Environment, and has full functional autonomy, according to what is established by water Spanish laws. The Tajo Basin District covers an extensive area in territories of Spain and Portugal. The Spanish part is limited by the basins of the Duero in the North, the Ebro and Júcar in the East and the Guadiana in the South, being its surface approximately 55.781km2. The Portuguese part (“Tejo e Riberas do Oeste”) has a surface of 25.666km2. The basin encompasses areas from different Spanish Autonomous Regions, being Castilla-La Mancha the one with the greater extension, followed by Extremadura, and the Madrid Region (which is almost entirely within the basin). The total population in the basin is 7.833.089 inhabitants (INE, 2010), and the population density in the basin is approximately 140 people/km2. Drinking water for both Capital city (Madrid and Lisboa) depend on Tajo River Basin. It was created in 1926. In the beginning, it was in charge of administering water for irrigation and hydroelectric power. Nowadays, the River Basin Authority’s main duties include water planning, water quality management, flood prevention, environmental matters and managing water rights and licenses, among others.