Flood Proofing

Permits and inspections will be required for flood proofing a home or a business. Check with local building inspectors to determine the specific requirements for your area.

Flood proofing refers to methods to protect your home and property or minimize the damage from floodwater. Choose the type that suits your home, property, and location best. There are 5 basic types.
  • Elevation: Raising the building until the lowest floor is above flood level.
  • Relocation: Moving the building out of the flood-prone area. This is the surest way to protect against flood damage. Elevation or relocation are considered the only reasonable choices for protecting a home that is subject to deep flooding (of more than 6 feet).
  • Flood walls: Flood walls, berms and levees are constructed to keep flood waters from reaching the home. Flood walls are usually concrete and berms are small levees are usually built from fill dirt. These measures work best in locations where flooding is less than 3 feet deep. In areas where floodwaters are subject to rapid currents, flood walls can't be used and they may not be appropriate for homes with basements.
  • Dry flood proofing: Means sealing a building to keep floodwaters out entirely. All areas below flood level are constructed to be water-tight and coated with waterproofing compounds or sheeting. Doors, windows, vents, etc. are either closed permanently or temporarily sealed. Dry floodproofing is generally not appropriate for houses with basements or crawl spaces, or where floodwaters are expected to be more than 3 feet deep.
  • Wet flood proofing: Means the building is modified so that floodwaters are allowed to enter the structure causing only minimal damage. In rooms below flood level, furnishings are lightweight and easily removed before a flood. Difficult to move objects like furnaces, appliances are either on elevated platforms, walled off, or installed on upper floors.
When flooding is imminent, everyone wants to sandbag, often because they don't know what else to do or have no other flood proofing measures in place.

Sandbagging's primary effectiveness is in conjunction with other flood countermeasures such as closing openings in existing flood walls or berms. Sandbagging is expensive, manpower intensive and less secure than other flood proofing methods.
People filling and placing sandbags - SCCDEM photo
Most do not understand the number of sandbags or the proper placement required to construct a wall that will withstand the pressure exerted by floodwater. According to a commonly used formula, it takes 100 sandbags to produce a 1 foot high wall, 20 feet in length.

Unless butted up to land contours or floodwalls, sandbagging by itself, is frequently insufficient for most residential protection needs.