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Sewage Spills

Image for the Sewage Spills page.
This page contains information about sewage spills and overflows and how we are working to minimise them.
Updated: 16/01/2020 2:56 p.m.
Photograph of fat blockage in a sewer pipe.
Fat build up in a sewer manhole​​​​​​​​​​​

What to do if you notice a sewage spill

If you see or smell a possible sewage spill please contact us to report the incident as soon as possible.

This is particularly important if the spill occurs in a public area or if the sewage flows into surface water e.g. streams, ponds, lakes, sea or a stormwater drain.

Please have an accurate location of the spill ready when reporting the problem.

Phone: +64 9 430 4200
Email: mailroom@wdc.govt.nz

Keep away from sewage spills

If you are not involved in the cleanup of the site, please keep out of the area if possible until the contamination has been removed and the area has been disinfected.

It is particularly important that children stay away.

Wash your skin if it comes into contact with sewage and see your health care professional if a wound becomes red and infected after any contact with sewage.


Our response to sewage spills

We have developed procedures for dealing with sewage overflows from the sewer pipe work, pump station and/or treatment plant facilities.

As soon as a spill is reported, the Sewage Spill Procedure is put in place. Our aim is to respond to all reports quickly to fix the problem and safeguard public health.

Follow the link below to download our Sewage Spill Procedure.

Sewage Spill Procedure [254kb]


Sewage spill records

We record all sewage spills that occur within the district including wet weather and storm events.

The records show the start and finish date of the spill, location, estimation of the quantity, cause, the public health risk as assessed by Northland Health Board’s Medical Officer and also the action taken.

The records for 2018, 2019 and 2020 can be viewed by following the links below.

Sewage Spill Record 2020

Sewage Spill Record 2019 [45kb]

Sewage Spill Record 2018 [186kb]​


Causes of sewage spills

On average 13 million litres of wastewater is treated each day within the Whangarei district. Occasionally pipe blockages cause overflows (spills) into the surrounding area.

The most common causes of blockages are fat build up, material/rags, plant roots or silt.

Wet weather spills are caused by rain water draining into the sewerage system.


What you can do to help to reduce spills

Dispose of fat correctly

When fat gets into a sewer, it forms lumps which stick to the pipe walls. Eventually the lumps become heavy enough to fall off and float down the pipe. If they are big enough, they can block the pipe completely and cause spills.

Please think carefully when disposing of fats. After cooking, let the fat cool, put it into a sealed container and then into your rubbish bin.

Pots, pans and plates should be scraped into the rubbish bin before being rinsed and washed. A sink strainer is also an effective way of stopping food scraps entering the waste system.

Commercial facilities dealing with large amounts of fat must have grease traps correctly fitted and regularly cleaned out.

Don’t use the toilet as a rubbish bin

Please don’t put rags, nappies, personal hygiene products or paper towels down the toilet as these products create blockages and can damage the pipes or get tangled up in the pumps. Dispose of these items in your rubbish bin.

Hazardous waste

Waste products such as old paint, engine oil, pesticides and solvents must not be disposed of down the toilet. Hazardous waste should be sealed in appropriate containers and taken to the Re-Sort Centre in Kioreroa Road to be correctly disposed of.

Don’t plant trees over sewer pipes

Give some thought when planting trees or large bushes in your garden. Because roots extend some distance underground, try to plant trees as far away from the sewer pipe as possible. Choose species that grow slowly and do not have large invasive roots - avoid willows as they have very invasive root systems.

Your local garden centre should be able to give you good advice on which plants to use.



During wet weather, rain water drains into the sewerage system and if the capacity of the system is exceeded, the wastewater can back-up and overflow from low points within it.

It is important to contact us as quickly as possible if you suspect a sewage spill is taking place, so that appropriate action can be taken to safeguard public health and the location recorded.

Low lying gully traps and water from roof downpipes are the major causes of stormwater getting into the sewerage system. Our on-going sewer inspections are identifying potential problems and helping to reduce stormwater inflows.

You can help by making sure there is no direct connection of stormwater to the sewer pipe (e.g. down pipes into the gully trap or low lying gully traps).

For further information about work currently under way to eliminate sewage spills, follow the link below.


Ownership and responsibility

Blocked drains

Property owners are responsible for the maintenance and upkeep of the pipe work from the building to the point at which the pipe joins into the Council system. This point is generally on the property boundary where it crosses from private to public land.

If there are problems with blocked or slow flowing drains, please contact a professional drainage firm to investigate. Property owners are responsible for the cost associated with any works carried out on their section of pipe.

We own and maintain the system of public pipes running from the property boundary to the wastewater treatment plants. We are responsible for the costs associated with unblocking public pipes.

Pipe breaks

Pipes may break for a number of reasons such as landslides/slips, excavations and pipe wear and tear. This will generally result in an immediate spill of sewage at the point of break.

If a section of pipe breaks or gets damaged on private land, it is the responsibility of the property owner to repair the damage and pay the cost of the work.

We are responsible for the maintenance and upkeep of all public sewer pipes. If you think that the damaged pipe is Council owned, please contact us and our contractor will investigate.

To view the list of approved and licensed contractors, follow the link below.

List of Registered and Licensed Contractors [82kb]

Pump station failure

Pump stations are managed by us and can fail for a number of reasons including blockages, power loss or mechanical breakdown.

The loss of a pump station causes wastewater to back-up in the gravity system. All pump stations have warning systems, which alert the operators of failure. As a backup, pump stations are also fitted with a loud audible alarm and or a flashing orange light.

If you hear or see these alarms please contact us immediately.


Whangarei District Council owns this website and the information, images and photographs in it are subject to copyright. No portion may be copied or republished without prior permission of Whangarei District Council. We have made every reasonable effort to provide accurate and reliable information. The use of any information is at the website visitor’s own risk and discretion.