The difference between what is covered under the homeowner’s insurance and what is covered under a flood policy really depends on what caused the flooding. If the flooding is an accumulation of surface water from outside your property, you will need a separate flood policy. If it is natural water entering from an opening in the roof, walls, or windows or if the water is processed tap water that leaks from your water pipes or appliances (water heater, washer), it should be covered under most homeowners policies.