The Alto Piura Project is located in the north of Peru in the Piura Region, provinces of Huancabamba and Morropón, both on the east of Piura City. The aim of the project is to transfer water from the Huancabamba river situated on the east of the Peruvian Andes to the Pacific basin by means of a tunnel crossing through the Andes. The Project includes various hydraulic infrastructure works and will have a significant impact on the economy of the region, as the water will serve to irrigate 50’000 ha of farmland providing 335 M cubic meters of water per year. In this way, the total area of irrigated land will increase by about 19’000 ha, which will contribute to expand the current agricultural exports of the region. The main components of the Project are the Tronera Sur Dam, the Transfer Tunnel and the Access Roads. The works at the Tronera Sur Dam comprise mainly a gated barrage with four radial gates (5.35 m high and 7.60 m wide) and a smaller radial gate (5.35 m high and 3.00 m wide). Additionally, there is a desander structure with 3 basins, each of them sub-divided into two smaller basins. The structure of the desander is approximately 51 m long and 44.8 m wide. The stilling basin of the spillway is 38.5 m long and 41.4 m wide. The desander is equipped with a gated flushing system and an intake structure which is located in the channel of the Huancabamba river. The design flow is 26.4 m3/s which will be transferred by the 12.7 km long tunnel with a hydraulic section of 15.65 m2.