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Staying safe during and after a flood

Flooding can happen without warning and when we least expect it. If you've been flooded it's important to drain, dry and clean your home quickly. Further information on cleaning up safely is available below.

  • Avoid floodwater where possible, and do not let children play in it. It can be dangerous and may contain sewage and other hazards.
  • If you have contact with flood water, flooded property or items contaminated with flood water, you should wash your hands with soap and water and dry them thoroughly afterwards.
  • You should also do this after going to the toilet and before preparing or eating any food. 
  • One of the main risks from contact with floodwater or contaminated items is gastroenteritis, which causes diarrhoea and vomiting. 
  • After a flood it's important to drain, dry and clean your property and belongings as soon as possible. This will reduce the risk of you and others becoming sick from a range of health hazards, including mould.

Cleaning up safely after a flood (PDF)

If you feel unwell after coming into contact with floodwater or contaminated items contact your doctor, or call Healthline for free on 0800 611 116.

In an emergency call 111.
BEFORE CLEANING UP

While it is important to drain, dry and clean your property as soon as possible, you should also make sure it is safe to enter and you are suitably protected.

 

Building safety and preparations
  • Do not enter your property if it has been deemed unsafe by a building inspector.
  • If your gas meter has been affected by water or debris, contact your gas supplier before entering your property.
  • Keep children and animals away from previously flooded areas until they have been cleaned and made safe.
  • Contact your insurer and landlord before you start work.
  • Take photos and videos of the damage and anything that needs to be thrown away before starting the clean-up, for insurance purposes and in case you need to show your property manager or landlord.

 

Personal safety

Before you start cleaning up you should put on protective clothing and ensure you have suitable gear.

  • Wear rubber gloves, sturdy footwear, a long-sleeved top and trousers.
  • Put on a face mask (such as a blue surgical mask worn to protect against COVID-19). if cleaning up mould in your home or property this should be upgraded to a well fitted N95/P2 face mask; these are available from hardware shops and chemists. 
  • Cover any cuts and grazes you may have to avoid them becoming infected.
  • Ensure you have a shovel to remove any gross contamination from your property, and bin bags for waste.

During the clean up avoid bringing footwear and clothing into the house that has been in contact with waste and debris, until it has been thoroughly disinfected.

CLEANING INDOORS & BASEMENTS

All floodwater and flood waste should be assumed to contain sewage. Sewage contains harmful bacteria and viruses and needs to be cleaned up as soon as possible. Keep children and pets away from the area until this is done.

Put on protective clothing and ensure you have suitable gear prior to starting (see advice in Before cleaning up).

 

Cleaning advice
  • Remove and discard contaminated household materials that cannot be cleaned or disinfected, such as mattresses, carpet and children's soft toys.
  • Take out everything that is wet and that can be moved – floor coverings, furniture, bedding, clothing, etc. Thoroughly wash and disinfect all items and dry in the sunshine
  • Clean and disinfect all contaminated areas with hot water and detergent, then disinfect with a solution of 1.5 cups of household chlorine bleach in 10 Litres of cold water (a household bucket).
  • Dry the property out as quickly as possible to avoid mould growth.
  • Clean children’s toys that have come into contact with floodwater in a solution of 1.5 cups of household bleach in 10 Litres of cold water (a household bucket) for 2 minutes. Rinse in clean water. Let toys air dry after cleaning.
  • Pay special attention to cooking utensils, work surfaces and other surfaces in kitchens such as floors and walls.
  • For utensils, dip them in a solution of 1.5 cups of household chlorine bleach in 10 Litres of cold water (a household bucket) for 2 minutes. Rinse in clean water. Or put them through a hot wash in a dishwasher.
  • Disinfect cleaning mops, brooms and brushes with the bleach solution.
  • After a clean up wash and dry dirty footwear, and wash your clothes separately.
  • Wash your hands and any affected parts of your body with soap and water after you have finished.

 

Hard surfaces
  • Scrub first with clean water and dishwashing liquid to remove all visible dirt. Then wipe down with a household disinfectant, for example 1 litre of bleach to 10 litres of water.

 

Cleaning basement areas
  • Check all floor drains in the basement to see that they are clear of debris and drain away water under the house. Try to increase the airflow to speed drying.
  • Drain any surface pools by pumping or bailing.
  • Wash or flush down walls, shelves and floors with clear water and sweep to remove contaminated water and sediment.
  • Use a solution of 1 litre of household bleach in 10 litres of water to rinse down walls, floors and other equipment. Leave on for 30 minutes before rinsing with clear water. Keep windows open during this treatment.
  • Use plenty of hot water and soap or dishwashing detergent for the final clean-up of walls, floors, cupboards etc.
  • Ventilate area by opening all windows or use fans, if power is available.
  • Use a commercial deodoriser, if necessary, to remove any remaining smells.
FOOD SAFETY

Floodwater can carry bacteria, chemicals and other hazards that can contaminate food, as well as cooking areas and utensils. You will need to carefully dispose of items and clean up areas that have been in contact with floodwater. 

Put on protective clothing and ensure you have suitable gear prior to starting (see advice in Before cleaning up).

 

After a flooding
  • Throw away all food and drinking water that has come in contact with floodwater, including things stored in containers. It is impossible to know if containers have been damaged and the seals compromised.
  • Do not eat garden produce if the soil has been flooded. Clean up and remove debris and sprinkle gardens with garden lime, if available.
  • Do not eat shellfish from the river mouth or harbour after a flood.
  • Follow any boil water notice instructions from your local authorities, if they are issued.
  • Get rid of all foods needing refrigeration when they have been unrefrigerated for more than 2 hours.
  • If the power has been off to the freezer for more than 2 days, get rid of all thawed food.

 

Cleaning and disinfecting

As surfaces and utensils may have been contaminated during the flood, it's important to clean up carefully afterwards:

  • Always wash and dry your hands before preparing food – if water is in short supply, keep some in a bowl with disinfectant for cleaning your hands.
  • Ensure all kitchen utensils and food preparation surfaces are clean before use. Rinse thoroughly in safe water, then disinfect by immersing for 1 minute in a solution of 500 ml (about 2 cups) of plain, unperfumed household bleach in 10 litres of water. Rinse again in safe water. Alternatively, boil all utensils for 1 minute and let cool.
  • Decontaminate any surfaces that may have come into contact with floodwater.
  • Cover all food with plastic wrap or store in waterproof containers.
  • Rubbish containing food scraps must be protected from flies and rats by wrapping the scraps or putting them in a sealed container.

 

Tinned food

You can keep food that has been in tins, but make sure they are thoroughly cleaned before opening by:

  • washing and scrubbing in warm water that contains soap or detergent, then rinsing in clean water
  • soaking for at least 1 minute in a solution of 500 ml (2 cups) of plain, unperfumed household bleach mixed with 10 litres of water, then rinsing in clean water from a safe supply
MOULD AND DAMPNESS

Drying and cleaning flood damaged properties as soon as possible will reduce the risk of mould and fungi damage. These can cause damage to your property, and also have significant health risks.

Put on protective clothing and ensure you have suitable gear prior to starting (see advice in Before cleaning up). It's recommended you wear at least an N95/P2 face mask when cleaning up mould in your own property. These are available from hardware shops and chemists. Commercial cleaners should consult occupational health or Worksafe for guidance on PPE requirements.

 

Drying your property

It is important that draining and drying of flooded houses happens as quickly as possible after the flooding. To aid drying of your home you can:

  • remove soft furnishings from your home and clean and disinfect them where possible
  • check for trapped mud and water in wall cavities
  • remove skirting and wall linings to above the flood line
  • ventilate and/or heat the home to allow drying to occur as quickly as possible
  • remove and discard contaminated household materials that cannot be cleaned or disinfected, such as mattresses, carpet and children's soft toys

If you are drying your property naturally, try and keep doors and windows open as much as possible. If using dehumidifiers, close external doors and windows.

Redecorating should also be delayed for at least three months after any repairs to prevent the risk of mould being covered.

 

Removing mould

If mould has developed on surfaces, take extra care when cleaning to reduce the risk of infection.

  • Clean the mould off as soon as possible to reduce exposure to mould spores and prevent mould spreading.
  • Remember good hand washing and drying during the clean-up process. If water is in short supply, keep some clean water in a bowl with disinfectant for cleaning your hands.
  • Use soap and water to clean the surface then apply a commercial mould product or household bleach solution.
  • For large areas consult a mould removal specialist.

 

Health issues caused by mould

Most moulds are harmless to healthy individuals and occur naturally in our environment. However, some moulds (such as Stachybotrys chartarum - a greenish-black mould) can release spores/toxins that are potentially harmful.

Exposure to mould can lead to symptoms such as stuffy nose, wheezing, and red or itchy eyes, or skin, and the development of asthma. Some people, such as those with allergies to moulds or with asthma, may have more intense reactions. Severe reactions may include fever and shortness of breath.

The risk of respiratory illnesses caused by dampness and mould is particularly serious for young children and tamariki with existing conditions such as asthma.

Cleaning a property damaged by flooding effectively will reduce the risk of young children, tamariki and rangitahi (teenagers and young adults) developing colds, influenza, pneumonia and bronchiolitis in the future.

WASTE AND STORM DEBRIS DISPOSAL

After a flooding there may be significant debris and waste outside your property which needs to be cleaned up and removed.  It should be assumed that anything which has come into contact with floodwater is contaminated and may be a health hazard.

Put on protective clothing and ensure you have suitable gear prior to starting (see advice in Before cleaning up).

 

Disposing of waste safely 
  • Children and pets should also be kept away from any flood contaminated areas and waste.
  • Put food and sanitary waste into bin bags before throwing it into a skip, to reduce the risk of rats and flies gathering.
  • Drain standing pools of water and empty containers like buckets, to reduce the risk of bacteria forming and mosquitos breeding. Always wear a mask and gloves when doing this, and wash and dry your hands thoroughly afterwards.
  • Hard surfaces such as patios and concrete paths can be cleaned and disinfected with bleach solution of 1.5 cups of household chlorine bleach in 10 Litres of cold water (a household bucket).
  • A garden hose is useful for washing down the outside of the property to remove silt, salt deposits and fine debris but do not use high-pressure hoses as they can blast contaminated matter into the air.

Contact Auckland Council if waste has been left for a long time and is beginning to become a serious hazard. Do not take items from skips, and minimise how much you disturb the items in the skip when putting in waste, to avoid shaking up dust and dirt.

 

Potential health risks from waste and debris

Storm debris and waste can pose a number of health risks if not cleaned. The most significant risks include:

  • Rats and mice may be attracted to the area, and can pass on diseases such as cryptosporidium or giardia, which cause diarrhoea and vomiting, and leptospirosis which causes high fever, headache and muscle pain.
  • Standing pools of water may contain harmful bacteria which when inhaled can risk causing serious illnesses such as Legionnaires’ disease.
  • Rotting food and sewage will contain harmful bacteria, and contact with this may cause gastroenteritis. Waste may also attract maggots and flies which can also carry disease and should be avoided.
  • Flood submerged garden crops and vegetables will not be safe to eat as if contaminated they can also cause gastroenteritis.
  • Mosquitos are likely to breed in large numbers in stagnant and standing water. While local mosquitos commonly found in New Zealand do not carry disease they can be a nuisance and cause skin infections if bites are scratched.
MENTAL HEALTH AND WELLBEING

After a flood it is understandable to feel sad, distressed, worried, confused, anxious or angry, even if you’ve not been impacted personally. Everyone reacts differently to difficult events, and some people may find them more challenging than others. Remember it’s ok to not feel ok.

For help with anxiety, distress or mental wellbeing, call or text Need to Talk? on 1737 to speak to a trained counsellor for free, 24 hours a day, 7 days a week.

Other organisations that provide mental wellbeing support include:

Specialist emotional support services for young people include:

FURTHER INFORMATION
Factsheets - after a flood

 

General advice

For advice and information during a flood visit Auckland Emergency Management or Northland Emergency Management 

 

For additional advice on cleaning up after the floods visit:

 

Health care professionals - emergency signage

The following resources are available to download for patients seeking help and advice:

Last updated 26.2.2024

For health advice call Healthline for free anytime on 0800 611 116
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