Valeira, Douro River (EDP, Portugal)

The Valeira Hydroelectric Power Plant, located on the Douro River in Portugal and owned by EDP, was commissioned in 1976. It dominates a watershed with an area of approximately 85,538 km². The dam is a concrete gravity type with a slight curvature. It features a 48-meter-high dam and a crest length of approximately 380 meters.
The power station, located on the right bank and integrated with the dam-spillway, is equipped with three Kaplan units, producing an average annual energy output of 663 GWh. The navigation lock, situated on the left bank, is 12.1 meters wide and 86 meters long, allowing the passage of boats weighing up to 2,500 tons with a draft of up to 3.8 meters. The maximum head to be overcome, varying with downstream water levels, reaches 33.5 meters.
This facility includes a Borland-type fish ladder integrated into the dam-wall, consisting of two chambers: the lower chamber communicates with the downstream, and the upper chamber exits into the reservoir, connected by a vertical shaft.