Because of the differing nature of these perils, each is treated differently by the insurance industry, and consumers are often confused about what their homeowners' policy covers and what it doesn't. Here's an overview of what coverage is available for specific types of disasters and how you get it. Homeowner's policies absolutely exclude damage from flooding, except for a narrow range of cases such as a pipe or water tank bursting. You can't get an endorsement to cover it at any price. However, if your community is in a flood-prone area, you can probably buy a special policy as part of the National Flood Insurance Program, administered by private insurers and backed by the federal government.
Any insurance agent can sell flood policies.
How much such a policy costs depends on what measures your community has taken to reduce the risk of flood damage. The state of California requires insurance carriers to offer earthquake coverage to anyone in the state who carries one of their homeowners' policies. Usually it's an endorsement to the regular policy, expanding the coverage for a fee. But if a California policyholder decides not to buy or renew the endorsement, the carrier isn't obligated to give her a second chance. Of course, given the risk, earthquake endorsements in that part of the country don't come cheap.