If you own a home, chances are you already have fire insurance. But even those whose homes aren’t in official flood zones should consider a flood insurance policy.

“You could be miles away from a river or water source but have a pretty significant flood risk,” said Butch Kinerney, spokesman for the National Flood Insurance Program.

Flood insurance, like earthquake insurance, is stand-alone coverage that can be sold in conjunction with a homeowner’s policy. But it has separate limitations and triggers.

Under most flood insurance policies, homeowners are eligible for coverage when a rising tide of water inundates at least two properties or 2 acres of normally dry land. It doesn’t matter whether the water pooled up because of a storm, a broken levy or a damaged water main. But the water does have to come from outside your home.

So if your toilet overflows or your pipes freeze and burst, that’s covered by your standard homeowner’s policy. It’s only when a wave of water or mud comes from the outside that you need flood insurance.

Flood policies impose separate deductibles for structure and contents coverage. So if you have $500 deductibles on both, you’d have to be out $1,000 before the coverage would start paying.

There is no coverage for temporary living expenses, even if you’re forced out of your home.

Also, flood policies generally don’t guarantee that you’ll get as much as it costs to replace your structure or contents. Instead, contents are replaced at their actual cash value. So if you lost a five-year-old sofa, you’ll get enough to buy another five-year-old sofa.

Flood policies don’t cover landscaping or swimming pools.

Maximum flood insurance coverage is $250,000 for structure and $100,000 for contents when buying through the National Flood Insurance Program. However, some property insurers will provide excess coverage for homeowners who want it. If you live in a high-risk area, your mortgage lender is likely to require that you buy flood coverage, at least to cover the balance of your loan.

In those high-risk areas, the coverage is costly, Kinerney said. Someone living near the beach in Florida, for example, might pay $6,000 annually for a policy. However, the average cost is about $500 a year, and those in low-risk zones can pay as little as $119.

Still, it makes little sense to buy any extra coverage if there’s no chance you’ll need it, said Robert Hunter, director of insurance with the Consumer Federation of America. The smartest thing to do is consider your personal risk.

The first step to doing that is to consider the government’s assessment of your flood risk. You can view or buy a flood map for your area at msc.fema.gov. However, unless you’re a geologist, you might have trouble understanding what you’re reading. If you want a simpler version, go to www.floodsmart.gov and plug in your address.

If your area has a flood map, the site will respond by telling you whether your risk is low, moderate or high. It will also estimate your flood insurance premium and suggest agents who could sell you a policy.

However, many people will find that there’s no current flood map, Hunter said. In that instance, you have to do a self-assessment of risk, evaluating your home’s location and surroundings. If your home is in a valley or on a hillside, insurance is worth considering – especially if the policy is cheap – Hunter said.

Los Angeles Times staff writer Kathy M. Kristof, author of “Taming the Tuition Tiger” and “Investing 101,” welcomes your comments and suggestions but regrets that she cannot respond individually to letters or phone calls. Write to Personal Finance, Business Section, Los Angeles Times, 202 W. First St., Los Angeles, CA 90012, or e-mail kathy.kristof@latimes.com.