How to Prevent Your House from Flooding

When protecting your home from flood damage, assess the risk flooding poses to your region and your house specifically. You should then carry out a range of preparations and renovations, such as installing a flood control system and applying sealants to any cracks in your home's foundation. Finally, consult your flood insurance agent to determine any additional emergency management steps they recommend.

Evaluate the Risk of Flooding in Your Home

The first step to flood protection is to determine how likely you are to suffer a flood in your area, and how well your house is built to withstand it. The FEMA Flood Map Service will show you the general flood risk of your region. After you enter your zip code, click "View web map," to see your area's flood zones, and click "Show all products for this area," to see reports of your region's flood history.

The flood maps include a number of zone markings that indicate the flood risk of a region and its relevant structures, such as bridges, dams and levees. Some of the zones you'll need to be able to recognize are:

  • Blue Zones: These are the 1% annual-chance zones. FEMA has determined blue zones are likely to face significant flooding at least once every 100 years. Although 1% may seem like a minimal figure, FEMA still considers this to be a high-risk designation, and you should take adequate steps to flood-proof your home.
  • Orange Zones: These are 0.2% annual-chance zones. FEMA states that orange zones are likely to face significant flooding at least once every 500 years. Since these regions face a lower risk of flooding than homes in a blue zone, your flood insurance rates will likely be lower. However, you should still make sure your house is not at risk of flooding due to leaks, or excessive surface runoff after rainstorms.
  • Yellow Zones: These are areas of undetermined flood risk. If you live or are looking to buy property in a yellow zone, we recommend you research the area's flood history. Ask neighbors what kind of flooding they've seen over the course of their time there, and make certain with your appraiser or flood insurance agent that the property is built to withstand any likely flooding.
  • Blue with Red Stripes: These are regulatory floodways. These zones often include a river and its surrounding floodplain, and are usually kept clear in order to allow water to drain from adjacent flood zones. However, some houses are built in, or extremely near to, regulatory floodways. If this is the case for your home, take extensive precautions to protect the home from flooding.

After you search out the maps for your region, note the year in which the map was made. Some maps are severely outdated, and the actual flood risks in your area might be different than they're presented on the map.

Next, work with your flood insurance agent or adjuster to determine the specific flood level of your house. The flood level is the height at which flood waters could rise during inclement weather. Ideally, your home should be built above this level in order to be reasonably protected from flood damage. If your house is situated at the bottom of a valley, for example, it could have a higher flood level than a neighbor's house that lies uphill of yours, since more water might flow toward your home.

Learn how flood waters might enter your house by evaluating the surface runoff the next time you experience significant rain or snowmelt. Note whether the water flows toward or away from your home, as well as any specific doors or basement windows that it pools around. This will help you understand the overall risk of flooding and identify any specific areas that might benefit from dry-proofing techniques.

Finally, note that your standard homeowners insurance policy does not protect you from the risk of flooding. Instead, you'll need to purchase flood insurance through either the National Flood Insurance Program or as an additional policy through your homeowners insurance company. You can find a list of average flood insurance rates here.

Protect Your House from Flooding

Once you've assessed your home's overall risk of flooding, take any needed steps to properly flood-proof your home. Flood-proofing can range from expensive home renovations to free, basic maintenance. The steps you take will depend on your home's risk and how well the home was previously built to withstand flooding.

Flood-Proofing Renovations to Protect Your Home

If you're building a house in a flood-prone area, or if your home was not built to withstand rising water, some flood-proofing work may be required in order to minimize flood damage. Here are some methods of flood control that will protect your home from rising water.

  • Raise your home on stilts or piers. While expensive to conduct retroactively, raising your house on stilts will raise your house's flood level. Since even an inch of flood water can lead to significant damage, raising your home above the flood level will substantially protect your home.
  • Install foundation vents or a sump pump. Foundation vents, a form of "wet flood-proofing," allow flood water to flow through your home, rather than pool around it. This both provides an outlet for flood water and relieves the significant pressure flood water can put on your walls and basement windows. Sump pumps are frequently used to pump water out of basements where flooding happens regularly. We recommend purchasing a sump pump with a battery backup, so that you can still use it if and when the power goes out.
  • Apply coatings and sealants. A form of "dry flood-proofing," coatings and sealants that you apply to your foundation, walls, windows and doorways will help prevent flood water from leaking into your house through cracks.
  • Raise your electrical outlets and switches. All outlets, switches, sockets, and circuit breakers should be at least one foot above flood level in order to prevent significant electrical damage in the case of a flood.
  • Install check valves on your pipes. Make sure that all pipes entering your house have valves to prevent a flooded sewage system from backing up into your home. Gate valves are preferred over flap valves, since they provide a better seal against flood pressure.
  • Grade your lawn away from the house. If your lawn tilts toward your house, rainwater will pool around your home. Use a heavy soil that contains clay content and sand to adjust the regrade your lawn so that surface runoff empties into a more appropriate place, such as a street gutter.
  • Make space between your mulch and siding. Wet mulch can rot your house's siding, which in turn can lead to leaks. Keep a space between your mulch and siding so that the base of your house can completely dry after rainstorms.
  • Point your downspouts away from your home. If your gutter runoff is not pointed away from your house, and in an appropriate direction, it will pool at the corners of your house and may eventually create leaks in your basement.

In addition to the renovations above, you should also protect your home's internal and external appliances by raising them above the flood level. Usually, you can achieve this inexpensively by placing the items on top of concrete blocks. Here are a few appliances that should be elevated above flood level:

  • Air conditioning units
  • Generators
  • Water heaters
  • Washing machines
  • Drying machines

Steps to Limit Damage After Flooding Has Begun

If a storm is imminent, or if flooding has already started, follow these steps to minimize flooding and water damage to your personal property:

  • Turn off the water line, if that is the source of the flooding.
  • Clear out your gutters and drains so that water can flow freely through them.
  • Use sandbags to block any gaps that will lead to flooding.
  • Move rugs, furniture, electronics and other valuables to a higher floor of the home, or at least elevate them from floor level.
  • Shut off your electricity at the breaker panel, should flood water be close to reaching your electrical system.
  • If it's not raining, open multiple windows to allow air to flow through your home.
  • Turn on your sump pump or use a shop vacuum to remove water as quickly as possible.
  • Photograph or videotape any flooding in order to document and defend your claim with your flood insurance provider.

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