Most homeowners policies include water damage insurance. It generally covers sudden and accidental water damage. It does not cover damage due to a homeowners negligence or failure to maintain a property. Commonly covered repairs may include a burst pipe or a water heater rupture. Coverage may pay for damage to the structure of your home and to your belongings due to water. This may not include damage due to water backup from an outside sewer or drain. It also does not include flood insurance. Coverage for water damage due to those reasons typically requires a separate policy.
Related, learn how to spot signs of water damage in a rental property.