The river Cadagua or Kadagua drains the Biscay

Biscay

Biscay is a province of Spain and a historical territory of the Basque Country, heir of the ancient Lord of Biscay. Its capital city is Bilbao...

an area of Encartaciones , from the Castilian

Castile (historical region)

A former kingdom, Castile gradually merged with its neighbours to become the Crown of Castile and later the Kingdom of Spain when united with the Crown of Aragon and the Kingdom of Navarre...

 valley of Mena

Valle de Mena

The Valley of Mena is a municipality of the province of Burgos, Spain, that borders Biscay.The town has 3,926 inhabitants and the town is under jurisdiction of Villasana de Mena District....

 to Barakaldo

Barakaldo

Barakaldo , is a municipality in the Basque Country in Spain. It is located in the Biscay province, administratively included in the "Basque Autonomous Community", on the left bank of the Estuary of Bilbao.Barakaldo is part of Bilbao's metropolitan area , and its official population...

 and Bilbao

Bilbao

Bilbao ) is a Spanish municipality, capital of the province of Biscay, in the autonomous community of the Basque Country. With a population of 353,187 , it is the largest city of its autonomous community and the tenth largest in Spain...

, where it forms the border between these municipalities and ends at the Estuary of Bilbao

Estuary of Bilbao

The Estuary of Bilbao lies at the common mouth of the rivers Nervion, Ibaizabal and Cadagua, that drain most of Biscay and part of Alava in the Basque Country, Spain. It is a large estuary long that extends from Bilbao to the Bilbao Abra bay, a widening that makes the final transition between...

. Another important town that this river crosses is Balmaseda

Balmaseda

Balmaseda is a town in the Encartaciones region of Biscay in the Spanish Basque Country....

.

The river takes its name from the small village where is located its first spring. Cadagua village is located in Valle de Mena (Burgos, Spain) surrounded by the beautiful landscape of "La Peña" mountains.

Four small hydropower plans produce electricity thanks to the river Cadagua. Until the last decades of the 20th century, this water power was also used by several mills that can be nowadays seen by the river basin.

Cadagua is a company which takes its name from this river. This company designs, plans and builds water treatment plants in order to improve the environment.