FCC will be responsible for the construction of the Ribeiradio and Ermida dams and the accesses to the Ribeiradio dam, as well as for the restoration of highway EM 569 on the Vouga river, near Aveiro, for EDP -Energías de Portugal-.The main dam -Ribeiradio- will be a concrete gravity dam with a circular directrix, a 262 m crest length, a maximum height of 74 m, and a volume of 230 000 m3. The spillway will be made up of three 13 x 13 m bays and equipped with segmented gates and a bottom outlet 2.5 m in diameter. The stilling pool will consist of a concrete reservoir with a maximum height of 6 m, located 135 m downstream.

The Hydroelectric Plant will be built in a circular pit 23 m in diameter and 36 m deep. It will be equipped with a single generator that will be fed through an underground hydraulic circuit consisting of a water intake, a headrace approximately 205 m long and 5.5 m in diameter, and restitution to the stilling pool.

In order to generate the counter-dam, the Ermida dam will also be a concrete gravity dam, but its directrix will be straight. It will have a 175.1 m crest length, a maximum height of 35 m and a volume of 75 000 m3. It will have a fixed lip spillway and a 1.2 x 1.5 m bottom outlet, and a 30 m stilling pool will be provided. The hydroelectric plant will be equipped with two generators fed by independent hydraulic circuits that will cross through the body of the dam.

The accesses to the Ribeiradio dam will be 1.34 km long on the right bank and 1.00 km long on the left bank with an average slope of 10%, a mountain layout and a 6.5 m platform, with two 2.75 m lanes and 0.50 m curbs.

Restoration of the EM 569 highway, on the right bank of the Ermida dam, will involve a length of 2.35 km and include the construction of a bridge over the Ribera de Salgueira.

Construction of the works will require more than 570,000 m3 of excavation, more than 370,000 m3 of concrete, and more than 7,700 tons of steel.

FCC has vast experience in the execution of hydraulic works. It is currently building more than six major dams of different types, including: the Castrovido, Yesa and Enciso dams in Spain which are 99 m, 117 m, 105 m high, respectively; El Zapotillo in Mexico, which is 132 m high; and the Tsankov - Kamak in Bulgaria which is 130 m high, through its ALPINE subsidiary.