Plumbing after a flood

Most of this page comes from NSW SES and NSW Health, whose own pages are linked as you go; the asbestos notes draw on national, NSW and Queensland government sources. It follows the order of going back into a home after flooding: the all-clear, the walk-through, then the services, the water, the sewage and the clean-up. Where an authority’s words are firm, they are kept firm.

Before the water arrives

Before any emergency, NSW SES asks households to know where their power, gas and water mains are, and how to switch each one off. Before evacuating, it says to turn off the gas and electricity to the home. It also suggests raising power points where possible, and having a safety switch installed by a licensed electrician and tested regularly.

Going back, in order

1. Wait for NSW SES

   Once people have evacuated, NSW SES is the one that says when residents may safely return to a flood-affected area. While the emergency is still active, do not go back to your property.

2. Look at the building before you enter

   NSW SES says not to enter a damaged building or structure unless the authorities tell you it is safe, and to make sure the property is structurally stable before entering: check the windows, walls and roof for damage, and be especially cautious of contaminants, including asbestos.

   Where asbestos may be in the damage, the national Asbestos and Silica Safety and Eradication Agency says it is “not recommended that you handle or remove asbestos yourself”, and NSW’s asbestos website says a home owner may legally take out less than 10 square metres of non-friable material themselves, but must meet strict safety standards and protect others from harm, while any friable material, or more than 10 square metres, must be removed by a licensed removalist. The national agency adds that a professional is the easier, safer and often cheaper choice. Asbestos waste may only go to a landfill licensed to take it; putting it in a household rubbish bin can bring a fine.

   NSW’s asbestos website says that when floods damage asbestos materials, they can become eroded, broken or friable, which causes health risks. SafeWork NSW says the small fibres given off when asbestos products are disturbed are harmful if inhaled and may lead to mesothelioma, lung cancer or asbestosis. It recommends a licensed professional even for 10 square metres or less of non-friable material. NSW’s asbestos website says asbestos waste may be disposed of only at a landfill holding a licence to accept it.

   When cleaning, the national agency says, never use high-pressure water, or scrubbing, sanding or any other abrasive method, on asbestos cement roofs or any other material containing asbestos. Queensland’s government asbestos site, in its list of what homeowners there should not do, includes sawing, sanding or scraping asbestos materials and drilling holes in them.

3. Go in with the power and gas off

   NSW Health’s advice is to make sure the electricity and gas are off before going inside, to use a torch for the first look, and to keep matches, candles and lighters unlit until you are certain no gas is present. Snakes, spiders and other animals may have moved inside to escape the flood.

4. Leave the services to the people licensed for them

   If the electricity, gas or water supply has been damaged or disconnected, NSW SES says not to try to reconnect it yourself, and to take extra care around the switchboard. NSW Health says not to use flooded electrical appliances, not to touch or handle any electrical equipment that is wet, and not to replace fuses or switch power back on to flooded wiring until a licensed electrical contractor has checked the installation and it is thoroughly dry. Any gas appliance or gas bottle that has been in floodwater needs a safety inspection by a qualified technician, and cleaning, before it is used. Gas water heaters are usually installed outdoors, so that can include the one beside the house.

5. Treat the water as unsafe until you know otherwise

   Throw out food and drink, including water, that has been in contact with floodwater, and keep a supply of fresh drinking water. NSW Health says: “Drinking water supplies can be affected by floods. If a ‘boil water’ alert has been issued in your area, follow it strictly to prevent illness.”

   A rainwater tank caught in a flood is likely to hold harmful microorganisms, and its water is not suitable for normal use. Don’t use it if the tank or its pipework is damaged, or if floodwater has touched taps or connections inside or outside the home; use the town supply for drinking and hygiene instead. Mark 3 covers tanks after a flood.

6. Remember what floodwater carries

   Floodwater and the debris it leaves behind may be contaminated with sewage and other hazards. NSW Health says to avoid entering floodwater; if you must, wear covered shoes, not thongs or bare feet, check the depth and current with a stick, and stay away from drains, culverts and water more than knee deep.

   For a home on a septic system, NSW Health notes that septic systems often don’t work during flooding or when the soil is very wet, and a flooded system may cause sewage to back up into the home. Until the ground has dried, only essential toilet waste should go to the septic tank. An aerated wastewater treatment system that has been inundated should not be used: isolate its electrical connection and call the service technician.

7. Clean from the top down

   Wear boots, gloves and eye protection while cleaning up. Hose mud and debris from the house starting at the highest point and working down to ground level, remove wet floor coverings and furnishings where possible, and start drying the house as soon as the water recedes. Never use petrol or diesel equipment, such as generators and pumps, in enclosed spaces.

Who checks what

The authorities name a different person for each part of the house’s services after a flood. This table gathers them in one place.

A bucket of disinfectant

For hard floors, walls, benches and sinks, NSW Health’s method is to clean with hot soapy water, then disinfect with a chlorine bleach solution or a product labelled as a disinfectant, and let it dry.

If you are unsure about the drinking water from a tank or bore after a flood, your local public health unit can help; NSW Health lists it on 1300 066 055. NSW Health’s full set of pages starts at maintaining health during and after floods and storms.