Caia (river)


The Caia or Caya is a river in the Iberian Peninsula, a tributary to the Guadiana. It is one of the main water courses in the Portalegre District, Portugal. Portugal does not recognise part of the border along the Guadiana between the rivers Caia and Ribeira de Cuncos, since the annexation of Olivenza by Spain in 1801. This territory, though de facto and de jure Spanish, remains de jure disputed by Portugal.

Course

It has its sources in the Serra de São Mamede and for the lower of its course it forms the international Portugal-Spain border. Finally it joins the Guadiana River southwest of the city of Badajoz in Extremadura, Spain.

Tributaries

  • Arronches, also known as Alegrete
  • Algalé

    Dams

  • Caia Dam, with the largest reservoir of Portalegre District