A topical word- allagamento, or flooding. Even as I write, two towns I lived in for a total of fifteen years are flooded, with a number of sfollati (evacuees). The river Bacchiglione has overflowed, wreaking havoc on Vicenza and Padova. The verb is allagare, and obviously contains the root for the word lago,lake. When the flooding is large or catastrophic, use alluvione. So if your kitchen is in a pool of water because the dishwasher leaked, it's allagato; but what happened to ole Noah was an alluvione.