Public Works: Floodproofing

When Water Attacks: A Homeowner's Guide to Floodproofing

Part I : Flooding

Wet Floodproofing
Wet floodproofing is a method that allows floodwaters to enter a building but minimizes damage. Damage can be minimized be either removing valuable items from the susceptible area or setting the valuable items up higher than the potential water line.

In the latter solution, structural components are replaced so that the new materials can withstand flooding. One example would be replacing wooden studs and gypsum wallboard with concrete block walls. Utilities such as the furnace, water heater, and laundry machines are either relocated to a higher floor or placed on blocks or platforms where flooding will not be too severe.

Obviously, wet floodproofing is not a good idea when a house is one story. It would be difficult to keep all water-sensitive items higher than a potential water line. However, many people wet floodproof their basements, garages, and accessory buildings quite simply by relocating anything that would be hard to move in a sudden flood situation, such as heavy appliances and electrical outlets. Keep in mind that light, moveable items, like lawn furniture and bicycles, can be moved, but only if there is enough warning. Fuse and electric breaker boxes should be located so you can safely turn the power off to the circuits serving flood prone areas.

Yet another solution would be to wet floodproof a crawlspace. If your crawlspace has a furnace in it or is used for storage, these items could be moved to the first or second floor. Vents should be placed on the foundation walls to ensure that floodwaters can get into the crawlspace to equalize water pressure.

Keep in mind that moving contents is dependent on adequate warning and the presence of someone who knows what to do. Flooding a basement or garage where there is electricity, paint, gasoline, pesticides, or other hazardous materials creates a safety hazard. There will still be a need for cleanup, with it accompanying health problems. Moving water lines, furnaces, or electric service boxes require a building permit from the Building Department.

Sump Flooding
Basement flooding caused by a saturated ground can be corrected by installing a footing drain around the foundation. The drain collects groundwater and directs it to a sump. When the sump fills, water is pumped out, usually onto the ground away from the building. Depending on the local conditions, the drain and pumping system may have to handle large volumes of water.

If the pump is blocked by debris, gets overloaded, or there is a loss of power, the system designed to keep groundwater out of your basement can act as a conduit to bring water in. You can prevent sump flooding by doing one or more of these floodproofing projects:

• Clean the pump intake to remove blockages
  
  
• Install a larger sump pump
  
  
• Add a second or third pump
  
  
• Connect the pump to a backup source of electricity, such as a battery system or generator
  
  
• Disconnect the downspouts from the footing drain
  
  
• Redirect the downspouts and sump pump outfall farther away from the house
  
  
• Run the sump pump outfall above ground level or use a check valve to prevent back flow

Part II : Basement problems
Part II.a : Basement Protection Berm
Part III.a : Sewer Backup Prevention - Floor Drain Plug
Part III.b : Sewer Backup Prevention - Standpipe
Part III.c : Sewer Backup Prevention - Overhead Sewer
Part III.d : Sewer Backup Prevention - Backup Valve
Part IV : Insurance