This project was opposed by environmentalists. On 19 December 1985 the lake was the subject of a major legal case when the Chilean Supreme Court ruled that international obligations such as the CITES need to be considered by the Chilean government and prohibited the use of the waters of Chungará Lake; the ruling by disallowing the use of the waters of Chungará Lake forced the Arica y Parinacota Region to seek other sources of water for the growing economy.