Retrofitting for flood-prone areas

If you llive in a flood-prone area, consider raising your house so that where you reside is higher above the ground and portenial floodwaters. Can you move your house to a higher part of your block, to avoid inundation?

Use water-resilient building materials when retrofitting.

Because you live in a flood-prone area, investing in water resistant materials makes good sense. Whether you are renovating by choice or rebuilding after flood damage, consider retrofitting your home with water-resistant materials that minimise damage and enable a faster, easier clean up after a flood event.

Building materials that could be exposed to water inundation should be given further consideration of their properties when wet, in deciding whether they are suitable for use. Consider the likely duration of exposure to wetness, changes to dimensions and strength when wet, water absorption rate, required drying time, and the cost and feasibility of replacement of components.

Here are some practical water resistant products:

  • Replace kitchen plasterboard wall linings with fibre cement sheeting then tiling over the sheeting using waterproof adhesive
  • Replace kitchen bench tops with stone or reconstituted stone products
  • For roof trusses and wall framing using steel or hardwood, which will withstand water inundation better than particleboard or pine
  • Use water-resistant products such as glass blocks to create a feature wall


Check your local building codes to find out whether they will permit you to bAnchor water tanks to ground to prevent floatation.

Rainwater tanks are a great addition to any property and enable self-sufficiency and water security. A significant flood event could uplift a full water tank drive it into your house or garage. Or water tanks could be swept downstream, causing damage to other properties.

A full 2000-liter rainwater tank weighs just over two tones, which could cause significant destruction. And you don't want the added cost of repairing or replacing and reinstalling tanks and pumps.

Securing the water tanks to the ground or wall by a strap or anchor will ensure they remain in place. In the event of a flood, If tanks tip over they could break water and gas pipes, or damage pressure pumps. 

Ensure your tank overflow is adequate and clear of debris. A locked tank overflow will cause water to flow over from the top of the tank, which may result in erosion of the tank base in heavy downpours. If your tank base is crushed rock or road base, sandbag the base to avoid erosion, which leads to instability.

Protect your tank pressure pump by removing and relocating it somewhere dry. If your pump becomes submerged, it is unlikely to operate and your warranty will be void. 

If your tanks are underground, relocate the pressure pump before bad weather. Contaminated water can be disinfected using a non-chorine food-grade tank water purification agent. 

Reinforce garage walls with work benches to prevent buckling.

Your garage contains many valuable items that are essential for maintaining your home and property, not to mention your cars. Lawn mowers, line trimmers, bicycles, power tool and cars all add up to a substantial investment. The stronger the garage structure the better your items will be protected. Garage benching is not just a practical addition that will provide a handy workspace, benches strengthen the garage walls during floods or high winds, to prevent buckling and damage under pressure.

Install electrical meter box and power points well above ground level.

Whether renovating or repairing, consider the location of your meter boxes, electrical switches and power points. Locating items higher up on walls may reduce the likelihood of having to replace wiring in the future.

Your electric meter box is usually located in a metal box on the outside of your house, and should be high enough to be above water, should you get flooded. Consider installing a new switchboard with safety switch if you have an old system; it could save a life.

If your power points are located at waist or shoulder height rather than just above the floor level, as they often are, you could avoid having to replace these if your house is flooded to below that level.

Be sure you use a licensed electrician to perform all electrical work.