What was the narrator referring when he said that the flood risk to Tokyo sounded like something out of a disaster movie?

Answer: A flood could hit Tokyo so quickly that the levee could break. In a short amount of time, this breach, or break, could cause severe damage to Tokyo's infrastructure, like a flood in a Hollywood disaster movie. Because Tokyo is home to a large population, a flood could cause massive damage to homes, businesses, and life.

Explanation: Because the floods happened recently there.