SANTIAGO – Mining group BHP will spend up to $93-million in environmental repairs and reparations after a Chilean court brokered an agreement in a lawsuit from the state over water use and related damage to a sensitive salt flat in the north of the country.

The lawsuit related to BHP's Escondida copper mine, the world's biggest, and the agreement involves the payment of compensation for environmental damage due to overdrawing water from the Punta Negra salt flat.

The lawsuit had been brought last year by the Chilean state which claimed Escondida had between 1990 and 2017 caused a severe decline in levels of the salt flat’s aquifer, partially or totally caused the loss of wetlands and vegetation and compromised the survival of its fauna.

The First Environmental Court, based in the northern Chilean city of Antofagasta, said on Wednesday it had rubber-stamped what it described as an "unprecedented" agreement that included a total of 19 measures to be taken by the miner.

These measures including technical studies of the salt flat and the drawing up of a management plan to repair damage that will require fresh approval from the environment ministry.

The plan should include measures to restore and maintain the fragile ecosystems of the salt flat, 170 kilometers southeast of Antofagasta, the court said, and protection of microorganisms capable of living in the dry, hot conditions.

The court said the eventual price tag for BHP of the measures would amount to up to $93 million. BHP said a joint monitoring group would be put together to oversee the implementation of the plan, made up of state, company and community representatives.

Water is a hot topic in drought-hit Chile, with both copper and lithium miners having faced legal challenges from local communities over their thirsty operations.

The Escondida mine now draws 100% of its water from the sea and passes it through a desalination plant.