In this case, it’s best to err on the side of caution. You don’t really know what contaminants might be in the water flooding your vegetable garden, so it’s best to pull the plants and dispose of them.  If it’s early enough in the growing season, it may be possible to replant some vegetables once the soil has dried out. Before replanting, add compost or other organic matter to replenish the soil. Avoid digging in wet soil.