Montezuma I become the 5th Emperor of the Aztecs in 1440. The capital city of the Aztec Empire was Tenochtitlan. It was an island city ( today Mexico City ). A great flood hit Tenochtitlan in 1450. To prevent future flooding Montezuma I built a 10- mile dam around Tenochtitlan.
Answer: Montezuma I prevented Tenochtitlan from being flooded by constructing a A ) Dam around the city.