Water damage in a home is usually covered by homeowners insurance under specific circumstances. However, damages caused by a flood, such as a storm surge, won't be covered by your homeowners insurance and will need to be covered by a separate flood insurance policy.
If you want to protect yourself from this risk, flood insurance is available from major insurance companies and even many independent brokers. The National Flood Insurance Program (NFIP) also provides a list of different insurers that offer flood insurance.
You can ask your current homeowner insurance agent or mortgage lender for recommendations.