Near a small town in central Colombia in South America, a mountain stream meets a large river at the bottom of a tall mountain. The large river (Ro Magdalena) is warm, while the small mountain stream (Ro Pequeo) is very cold, as it begins at very high altitudes and is comprised mostly of water from melting snow. While a few dams and hydroelectric plants have been constructed along the mountain stream to take advantage of its flow to produce electricity,