Heavy rainfall caused a great deal of destruction in the Valley of Carranza (Bizkaia) back in 1978 and revealed the remains of ancient timber dams, which allowed to know in situ the technique used in the construction of these old-time hydraulic structures of clear medieval origin.
Well into the 19th century the majority of the watermills in the Valley employed small, straight single-walled dams to provide power to the water-raising machinery. (more…)