Chulalongkorn U Alumni

What were the longest floods in Roman History? In some other places, rivers would break and it would take quite a while before the break would be fixed up again. Were there any similar cases within the Roman territories? What rivers were they? When did they occur? How long did the floodings last before the Romans fixed things up? I am interested in: 1. The Late Republic 2. Early Empire (Pax Romana) Thank you Please provide some academic sources if you can.