Renters insurance covers water damage under personal property coverage. But in some cases, it is an add-on endorsement under water backup coverage. You may also have coverage for water damage under personal liability coverage. The circumstances that caused the water damage determine what part of your policy covers it.
Don’t confuse flood as part of water damage because it is usually a separate policy and is rarely an endorsement.
MoneyGeek’s guide about what renters insurance does and doesn’t cover delves deeper into a policy’s coverages and optional endorsements.