A sealed-looking package is not necessarily waterproof. FDA says to discard flood-exposed home-canned food and containers with screw caps, snap lids or similar closures, along with nonwaterproof packaging. Damaged cans should also be discarded. Some undamaged commercial all-metal cans and retort pouches can be salvaged only by following FDA's complete cleaning and sanitizing procedure. Do not taste food to test it. Photograph losses for your records when safe, but keep suspect food out of use.
Read more:FDA: Food and water safety after floods