Prieto Abogados Advises on US$1.5 Billion Mining Infrastructure Project in Chile

The project will significantly increase the mine’s output—positioning it among the world’s top 15 producers of copper, molybdenum, and gold—and includes the development of a second seawater pipeline (SIAM II) to secure a sustainable long-term water supply for mining operations in the drought-stricken Antofagasta region.

Prieto advised the Bonatti–Sigdo Koppers consortium, selected for the construction of the new SIAM II pipeline under an EPC contract with Aguas Esperanza, a joint venture between infrastructure developer Almar Water Servicios and energy company Transelec. The firm's team was led by partners Nicolás Yuraszeck and Mario Gorziglia, supported by associates José María Lagos, Emilia Valenzuela, Josefa Reyes, and Aníbal Larraín.

The financing structure also includes the acquisition of the existing SIAM I pipeline, with a reported transaction value of US$600 million. The new SIAM II pipeline will run parallel to the original and is set to transport 650 litres of seawater per second, ensuring the mine’s growing water needs are met without drawing on continental or desalinated freshwater resources.

Operations are scheduled to begin in 2026, following a 20-month construction period expected to generate over 1,500 jobs.

This major transaction brought together an extensive network of international and Chilean legal counsel. Prieto Abogados’ expertise and deep experience in infrastructure and energy projects played a critical role in enabling the successful structuring of this complex cross-border deal.

We congratulate Prieto Abogados on their contribution to one of the most significant mining infrastructure developments in Latin America this year.