Sandbags are useful to protect your property from some types of flooding. Find out where they can be used, how to make them and what to do with them after the floods.

Sandbags can be used:

  • across doorways for houses on a concrete pad
  • across a garage door
  • to divert water down hill

However they can’t stop water coming from under the house and through the floorboards or other access points.

Making sandbags

Make them out of feed bags, hessian bags or plastic (polypropylene) sacks. If you have only the plastic open weave type bag, put one inside the other. Don’t use kitchen rubbish bags as they will slip around in the water and may split.

Sandbags are available from:

Textile Bag and Sack Company
55 Byron Street, Sydenham
tel (03) 961 3535

Filling sandbags

Fill them with a heavy or sandy soil or with sand. Don’t use gravelly or rocky soils as they will let the water through. Sand is available from any garden centre.

It’s easiest if there are two people to fill the bags.  One holds the bag and the other shovels the soil or sand in. Only fill it half to two thirds full. This gives the soil or sand room to expand as it holds the water.  Don’t tie or seal the bag – when you put it in place, fold the flap into a triangle and tuck it under the bag.

diagram showing how to build a sandbag wall for flood protectionBuilding the sandbag wall

Place your sandbags lengthwise and parallel to the water flow with the tucked end facing the flow. If you need more than one row’s height, place the second row crosswise, and the third row lengthwise to strengthen the wall.

Drying sandbags for re-use

When the water has receded, separate your sandbags, lay them out or stand them up and let them dry out thoroughly. When they are dry, store them for use again. If you leave them wet, they will rot or deteriorate quickly.

Disposing of sandbags

To dispose of sandbags scatter the sand in your garden. Please do not leave on the kerbside as this may clog up the drains.