This is an article from El Salvador about the negative effects a proposed gold mine would have on local water supplies.
Here's a followup article on the proposed Santurban mine I've written about recently. Now that the Greystar company's environmental license will clearly not be granted for mining in the fragile paramo ecosystem, the question is what their next move might be. It is possible that the company would simply alter its plans to do all the mining and extraction just outside of the officially-delimited paramo zone. This would obviously lead to the same problems of water contamination and ecosystem destruction that were the concern with the initial proposal. Because the paramo forms an interdependent, coherent system with the lower-altitude Andean forest ecosystems, and the major cities of Santander department depend on water that flows down from the paramo through these other areas, the only ecologically viable solution is to keep mining out of the entire area. The article posits a system of payment for environmental services, whereby the residents of these cities that depend on the water would pay the people and towns that live in the fragile paramo ecosystem, in return for the latters' keeping the ecosystem and its water healthy and clean. I believe this is what New York City does with the Adirondack areas from which the city derives its drinking water.