In Portugal, the Varosa dam was built on a small tributary of the Douro River. The concrete vault is best known for its impressive staircase built in terraces, allowing the natural rock and the structure of the dam to merge.
The Varosa Dam
The Varosa is a Portuguese river about 45km long, which originates in a lowland village not far from Tarouca. It flows into the Douro, a Spanish-Portuguese river that passes through the city of Porto. Before flowing into the Douro, the Varosa River follows a sudden geographical subsidence at Sande. This brutal topographic descent interested industrial companies wishing to draw electrical energy from the river’s currents. An hydroelectric dam was therefore built in 1976, the Barragem de Varosa (Varosa Dam). It is an arched concrete dam with a height of 76m above the natural terrain. The length of its crown is 213 m long and 3.44 m wide making it one of the smallest hydroelectric power plants in Portugal.
A concrete staircase on a sharp relief
What makes it remarkable, however, is probably its monumental maintenance access staircase on its west end. These stairs are arranged on a succession of concrete terraces that form a buffer between the dam to its right and the natural rock to its left. This construction extends the relief and of the rock by using rough concrete, reproducing the mineral language. The stairs are so steep that it can be difficult to choose the best option between climbing them or climbing the rock face. The concrete stairs seem to flow into the granite valley and its sharp relief. The geometric shapes function as a graft to connect the human industrial concrete structure to the natural steep rock.
All pictures are from © Vitor Oliveira