If flood waters have covered your garden, consider the produce unsafe to eat for humans or animals.  If flood waters have contacted the edible portion of a crop it is illegal to sell. 

If touched by flood waters discard: leafy vegetables, fleshy fruits or vegetables (like tomatoes, berries, & summer squash), corn, grains, and even produce with a hard protective skin.  Root crops that are ripe or near harvest should also be discarded.  Record all losses. 

If the edible portion develops after flood waters recede it should be safe to eat.  Underground vegetables roughly four months from harvest should be safe at maturity. Discard greens, wash, and disinfect in a weak bleach solution. Then peel and cook thoroughly before eating.

Segregate non-flood affected crops and sanitize yourself and your equipment between fields to avoid cross contamination

When it comes to food safety: When in doubt, throw it out.

Your county Extension agent has more information. https://extension.wvu.edu/community-business-safety/disaster-preparedness/flooding/managing-gardens-after-flooding