The slopes of the volcano drain westward, eastward and southward towards the Calientes and Callazas rivers in the east and west of Yucamane, respectively. Both rivers flow southward and ultimately join to form the Locumba river, which ends in the Pacific Ocean. The water in these rivers contains large quantities of arsenic derived from volcanic rocks, including Yucamane's volcanic rocks; arsenic in drinking water is linked to internal organ damage and cancer.