By Jane Chambers
BBC correspondent, Santiago, Chile
A dispute over water rights has hit one of Chile's largest copper mines, Los Pelambres.
Locals say the mine's new dam is cutting off and potentially poisoning valuable water supplies.
Supporters of the mine dispute the claim and point to the employment the operation brings to the north of Chile.
The dispute has fuelled a national debate about how to attract mining investment, while at the same time protecting scarce resources like water.
It is just one in a series of cases where more and more Chileans are complaining that companies are damaging their environment.
The El Mauro dam, which has been built by the company Antofagasta Minerals at the top of an arid valley in the north of Chile, has split the local community.
'A great opportunity'
Copper mines can make a huge impact on the environment
Farmers say the dam has cut off existing water supplies and could poison what's left, because residues from the waste rock, treated to extract copper, filter into the ground water.
But Maria de la Luz Vasquez who is a specialist in environmental issues for the Mining Ministry points out that there are many advantages to mining projects like Los Pelambres.
"The benefits with projects like this are the employment it brings to the region," she said.
"There is better paid work, which is full time and more skilled, and for us this is a great opportunity."
Her views are echoed by many of the locals who support the mine and accuse its opponents of standing in the way of development.
But farmers like Victor Ugarte insist that the dam has cut off natural wells, which are needed when the rain fails.
The dam was approved in 2004, but farmers from the valley below have won a court appeal over water rights which are needed for the project to proceed.
The case is now before the Supreme Court and most expect a verdict this year.
This is not just a local issue.
Water is becoming increasingly scarce, especially in Chile's north, and cost and availability is a growing problem for existing and developing mining projects.
The government and Antofagasta Minerals say they are taking steps to ensure there is no threat to the environment.
But environmentalists disagree. They say it is time to decide what is more important, water or the money brought in by these mines.