Living room flooded
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As a very powerful Hurricane Florence churns toward the Carolinas, with landfall expected Thursday night, the threat to lives and property is imminent. Besides dangerous winds, Florence is predicted to inundate the mid-Atlantic region with water.

Flooding is the most common and one of the costliest weather disasters in the U.S., according to the National Oceanic and Atmospheric Administration.

From 1980 to 2013, flooding cost Americans more than $260 billion in damage; from 2006 to 2015, federal flood insurance claims averaged $1.9 billion annually, according to data from The Pew Charitable Trusts. And those figures don’t include the toll of hurricanes Harvey, Irma and Maria from 2017.

The best way to avoid flooding, of course, is to stay above water.

“The one nasty thing about flooding is that there is no (margin) of safety other than elevation,” says Tim Reinhold, former chief engineer and research vice president at the Insurance Institute for Business & Home Safety and now a wind engineering and natural hazards consultant on Florida’s Gulf Coast.

“Once the water reaches the level of your floor and goes an inch above, you have significant damage,” Reinhold says.

It’s important to know the flood level at your home — an official measure of how high floodwaters could rise where you live. You can find this information by checking the flood maps at the Federal Emergency Management Agency’s website. Your local building department and your home insurance agent should have that information, too.

Even a home on a hill needs flood-proofing. Here are six measures that will help you protect your property from flood damage.

Be sure to use licensed and insured contractors to make any modifications. Check with your local building department about permit requirements.

1. Safeguard in-home electrical and climate systems.

Switches, sockets, circuit breakers and wiring should be at least a foot above the expected flood level in your area, according to the Insurance Institute for Business & Home Safety.

Modify your furnace, water heater and any other anchored indoor equipment so that it sits above your property’s flood level.

2. Anchor and elevate outdoor equipment

Fuel tanks, air-conditioning units and generators should be anchored and raised above flood level. Fuel tanks that are not anchored can break free, and severed supply lines will contaminate the ground, the IBHS warns.

Jose Mitrani, associate professor emeritus in the school of construction at Florida International University in Miami, says electrical power units and generators should never sit on the ground.

“These backup facilities will be inundated (by water) and useless,” he says.

3. Modify your water valves

A flooded sewer system can cause sewage to back up into your home. The IBHS recommends installing an interior or exterior backflow valve.

The Federal Alliance for Safe Homes, or FLASH, recommends gate valves. They are more complex, and you operate them by hand. But they provide stronger seals than flap or check valves, which open automatically to allow water to flow out and then close when water tries to get in.

Valves should be installed on all pipes entering the house, FLASH advises.

4. Determine how water flows around your house

The grading or slope of the ground can direct water to your house or away from it. Obviously, it’s best if the home was built so that water drains away from it.

This can be determined easily by watching how water flows or accumulates during an average rainstorm, says Leslie Chapman-Henderson, president and CEO of FLASH. If your street is prone to have standing water after an ordinary rainstorm, talk to your county planning or environmental services department, she advises. “A major part of their job is water flow, and they can make suggestions,” she says.

5. Take extreme measures: Opt for a retrofit

If your home floods frequently and moving isn’t an option, you may need to take drastic and costly measures.

FLASH’s home safety program offers these options:

  • Raise your home on piers or columns so that the lowest floor is above the flood level. It’s expensive, however. Experts tell FLASH that such an undertaking would cost at least $20,000.
  • “Wet-proof” your home by installing foundation vents that would allow water to flow through the building, instead of rising inside and causing more damage. You’d need at least two vents on different walls. A 1,000-square-foot house would require 7 square feet of flood vents, according to FLASH.
  • Do some “dry-proofing” by applying coatings and other sealing materials to your walls to keep out water.

6. As waters rise, take last-minute measures

  • Clear gutters, drains and downspouts.
  • Move furniture, rugs, electronics and other belongings to upper floors, or at least raise them off the ground floor.
  • Shut off electricity at the breaker panel.
  • Elevate major appliances onto concrete blocks if they’re in danger of being flooded.