The effects of flooding can be widespread or localised. From contaminated waterways and kaimoana (shellfish) to flood-affected properties and damaged food items, there are a number of health hazards you should be aware of after a flood.
Has your home been flooded?
It is possible that your house may be assessed as being 'unsanitary' if flood waters have been through it. This means you may not be able to continue to occupy the building until repairs have been made.
You will need to contact your insurers to arrange an assessment before calling in qualified contractors to do the work needed to make your home safe and sanitary again.
Has there been flooding across your property?
If the answer is yes you should be aware that:
- The flood water may have affected your septic tank and effluent disposal field. If gully traps are over-flowing or your toilets are not working properly, you should not use the toilets until they have been repaired.
- You will need to use alternative toilets, i.e. public toilets if there are any nearby, portaloos or portable chemical toilets.
- Even if the floodwater has dispersed and everything appears to be normal, there may still be unseen problems below the ground. Clues that your toilet system may be malfunctioning include a bad smell, gully traps flooding, or toilets making gurgling noises. Contact a certified plumber/drainlayer to investigate.
Has your property slipped or slumped?
If your house has been directly affected by a slip or floor levels have slumped, it may be assessed as being dangerous. This will mean that you can no longer live in your home until repairs have been made.
If this is the case you should:
- Contact your insurers to arrange an assessment and repairs by qualified tradespeople.
- Apply for a Building Consent, a process which is likely to be treated by the council as emergency work. Please contact your local district council building officer for guidance.
Whāngārei District Council - 0800 932 4636
Far North District Council - 0800 920 029
Kaipara District Council - 0800 727 059
The Earthquake Commission covers landslip damage to residential property as well as damage caused by earthquakes and some other natural hazards.
For more information phone 0800 326 243 or visit:
Immediate welfare and accommodation
If you need to get out of your home due to flooding or flood damage you should:
- Phone your local district council to get advice on where to go and register effects to your property.
- Contact Work and Income on 0800 559 009 or call into your local Work and Income office – listed in the telephone directory – and quote the registration number you got from the council.
For further health information on restoring a home after flood damage, contact an environmental health officer at your local district council or a health protection officer at the Northland District Health Board – phone 09 430 4100.
Other health hazards from flooding
There are a number of health hazards to be aware of after flooding. Some of the key things you can do to protect yourself and your family from the potentially harmful bacteria caused by flooding are:
- Wash and dry hands frequently especially before eating food.
- Avoid eating or smoking in flood-contaminated areas.
- See a doctor if you get a cut or puncture wound – like standing on a nail.
- If you're carrying out clean-up activities, wear appropriate personal protective equipment such as gumboots and gloves.
In your home – food
Do not eat any food that may have come into contact with flood water.
Inspect canned foods and discard any food in damaged cans – clean the outside of the container or tin before opening.
After prolonged power cuts:
- Do not use frozen food that has thawed or refrigerated food that has warmed up – if in doubt throw it out.
- Cook food thoroughly.
- Throw out cooked food if it can not be refrigerated or eaten immediately.
- Always wash and dry your hands before preparing food – if water is in short supply keep some in a bowl with disinfectant.
In your home – drinking water
- Don't drink flood water or tank water which may have been contaminated by flood water. Your local district council will alert you if the local water supply is contaminated.
- Check rain water tanks, particularly in-ground tanks. If they have been inundated with flood water, the water may be contaminated and should be removed.
- Disinfect the tank using enough chlorine to give an initial chlorine dose of 5mg/L. After adding, allow to stand for at least one hour.
Cleaning in and around homes and buildings
- If there has been a backflow of sewage into the house, wear waterproof gloves and rubber boots during the clean-up.
- Clean walls and floors with soap and water.
- Clean food contact surfaces (benches and fridges) with soap and water, then disinfect using a solution made up from one cup of bleach to a bucket of clean water.
- Wash linen, towels and clothing in hot water and disinfectant and dry thoroughly.
- Items that cannot be washed and disinfected should be thrown out. Remove and discard absorbent household materials such as mattresses, upholstered furniture, curtains, wall coverings, rugs and plasterboard.
If for any reason your house is assessed as dangerous or unsanitary you should not be living in the building until repairs have been made unless otherwise advised by your council. Note: all records for any remedial work undertaken need to be kept and provided to your local district council when required.
Swimming and shellfish gathering
If you're swimming or in contact with river or sea water:
- Stay out of the water until it is clear – you can see your feet when you're standing in it – after heavy rainfall.
- If there has been sewage contamination do not swim in rivers and coastal areas for two days and upper harbour areas for five days.
- Any water activities where you are likely to have your head under water (e.g. kayaking, surfing or dinghy sailing) should follow the same advice, i.e. stay out of the water until it is clear.
If you're gathering shellfish:
- Avoid collecting shellfish contaminated by flood waters for at least a week – this should be extended to 28 days if contamination by human sewage is also likely.