A Cochilco study projects seawater will account for 68% of water use in Chile's large-scale copper mining by 2034, up from 41% in 2024. Total water demand will rise from 18.5 m³/s to 20.6 m³/s, as continental water use falls.
Chile's Copper Commission (Cochilco) released the study 'Projection of water demand in copper mining in Chile' for 2025-2034. The report forecasts water demand growing at an average annual rate of 1%, matching expected copper production rises, existing operation expansions, and new projects. In 2024, total consumption stood at 18.5 m³/s, with 41% seawater and 10.9 m³/s continental water; by 2034, it will reach 20.6 m³/s, with 68% seawater and 6.7 m³/s continental, due to structural water scarcity in mining areas. Growth will not be steady: increases from 2025-2027, a dip in 2028-2030, and rises again from 2031 due to shifts to sulfide minerals requiring more water. The 2026-2027 period is a milestone with projects like Collahuasi's C20+, Codelco's Northern District plant, and Aconcagua. Antofagasta Region will account for 49% of national consumption by 2034, with Tarapacá, Antofagasta, and Atacama leading seawater uptake. Patricia Gamboa, Cochilco's director of studies and public policies, stated: 'Investments are becoming increasingly viable from a strategic perspective, though costs remain significantly higher than continental water supply due to infrastructure complexity.' Costs average US$4.45/m³ for desalination and pumping, US$1.87/m³ for direct pumping, with energy pivotal. Environmentally, it eases continental pressure but poses risks in marine intake, brine discharge, and energy footprint, urging integrated territorial planning.
