Most of the homes currently underwater in the Houston area are probably not covered by flood insurance. Only around 15% of homes in Harris County (the county encompassing much of the metro Houston area) are in a designated flood zone. To get a mortgage on a property in a flood zone, homeowners have to purchase flood insurance from the National Flood Insurance Program.
Few who are not required to buy flood insurance do so. Many people wrongly assume their homeowners insurance policy covers flooding. It doesn’t. The standard homeowners insurance policy excludes flood damage. Wind damage is covered.
The standard homeowners policy most people purchase is the HO-3 or “Special form” policy, developed by the Insurance Services Office (ISO). It provides the minimal level of coverage required by mortgage providers. HO-3 is what is known as an “all risks” policy because it covers all perils not specifically excluded in the policy.
You can download a sample of the entire form here.