 The Colonial Spanish began mining in the 16th century in the Pachuca area, but the mines were suffering from flooding by 1725.In 1741, Pedro Romero de Terreros and Jose Alejandro Bustamante started a drainage program using an adit.The native Mexican Amerindians were often enslaved to work the mines, despite the Royal mandate for Colonial Jesuit Reductions and later Franciscan Indian Reductions.