Cadagua

Cadagua is a river in northern Spain, located primarily in the province of Biscay in the Basque Country. It is a relatively short river, approximately 52 kilometers (32 miles) in length.

The river rises in the Sierra Salvada mountains and flows generally northwards, passing through towns such as Balmaseda, Zalla, and Alonsotegi, before discharging into the Estuary of Bilbao, where it joins with other rivers to form the Nervión River. The Nervión then flows into the Bay of Biscay.

The Cadagua river basin is characterized by its industrial history, having been a significant source of water for various industries, particularly iron and steel production. This industrial activity has, in the past, led to environmental concerns regarding water quality. However, efforts have been made to improve the ecological status of the river in recent years.

The river valley also supports agricultural activities and provides a habitat for various plant and animal species, contributing to the biodiversity of the region. Fishing, although impacted by past pollution, is present in some areas of the river.