Valeira Dam is a concrete gravity dam on the Douro. The construction of the dam began in 1971. The dam was completed in 1975. It is owned by Companhia Portuguesa de Produção de Electricidade

On the left side of the dam is a lock, which can handle ships with the following maximum properties: 83 m in length, 11.40 m on the beam, 3.8 m load-draught and a cargo capacity of 2500 tons