Keeping floodwater out of the house

Floods are the most common and costly disaster in the United States, and anywhere it can rain, it can flood. Many of the ways to cut a house's flood damage are small and inexpensive. Each one starts from how high the water could get, called the potential flood elevation.

What you need

• The home's address, to look up its flood zone and flood elevation
• Hydraulic cement or mortar and masonry caulk, for foundation cracks
• A licensed plumber and a licensed electrician for the work that needs them

Steps

1. 1

   Find out how high water could get

   Look up the home's flood zone and base flood elevation on FEMA's Flood Map Service Center. The local planning, zoning or building office keeps the flood maps too. Ask neighbors how high the water has come in past floods.

   30 min

2. 2

   Stop sewer backups

   Fit drain plugs in the basement floor drains. Have a licensed plumber install backflow valves on every pipe entering the house, which let water flow out only, so floodwater can't come back up through toilets, sinks and drains.

   30 min

3. 3

   Raise the electrical system

   Have a licensed electrician raise the panel, outlets, switches and wiring to at least 1 foot above the potential flood elevation.

   30 min

4. 4

   Raise the outdoor equipment

   Have air conditioning condensers, heat pumps and water meters set on platforms at least 1 foot above the potential flood elevation.

   30 min

5. 5

   Move or raise the indoor equipment

   The main parts of the heating and cooling system can move to a higher floor or the attic. The washer, dryer and water heater can go above the ground floor. Where that isn't possible, low floodwalls and shields protect them in place.

   30 min

6. 6

   Have any fuel tanks anchored

   Indoor and outdoor tanks get fixed to a heavy concrete slab, or outdoor ones strapped to ground anchors. Floodwater can move and rupture a tank that isn't anchored.

   30 min

7. 7

   Seal the foundation

   Fill foundation cracks with mortar and masonry caulk or hydraulic cement, coat basement walls with a waterproofing compound, and keep the floor drains clear.

   60 min

8. 8

   Have a plumber add a sump pump with a battery backup

   It pumps groundwater away from the house, and the battery keeps it running if the power goes out.

   30 min

9. 9

   Keep the water moving away outside

   Have the gutters, downspouts and splash pads kept clear, keep nearby storm drains free of debris, and grade the yard so it slopes away from the house.

   20 min

The day before a flood

Turn on the sump pump and close any backflow valves. Move papers, furniture, rugs and electronics to an upper floor, or at least off the floor. Set major appliances on concrete blocks. Put out sandbags or other temporary flood barriers. Shut off the power at the breaker panel. If you're told to evacuate, go right away, and never walk, swim or drive through floodwater. Six inches of moving water can knock a person down.