The purpose of the works was the construction and supply of equipment for the fourth section of the Vale do Gaio Water Circuit, as part of the Alqueva Multipurpose Initiative, to divert a certain volume of water from the Barras tank to Vale do Gaio reservoir. The works are located in the town of Torrão, in the Alcácer do Sal are of the Setúbal district.

The works included the following tasks:

• Intervention at the derivation node towards the area known as Blocos do Torrão (node located downstream from section 3 of the Vale do Gaio carry pipe) to the installation of a valve chamber to enable excess pressure to be reduced;
• Section 4 of the Vale do Gaio gravity discharge channel, approximately 3,349 m long, with DN700 steel pipe;
• Filtration plant located nearly 250 m from the start of section 4, composed of two filters and the corresponding tank to collect water for washing the filters;
• Building vent frames, bottom discharge chambers and the corresponding replacement trenches, as well as flow-rate measuring chambers and water-line crossings;
• Building the structure for the delivery terminal at Vale do Gaio reservoir, made of reinforced concrete with walls, gabion walls and retaining walls, including a DN600 bypass circuit for a future hydro plant.