Storm and Flood Plumbing Auckland

Overflowing Gully Traps, Sewage Backing Up, Blocked Downpipes and Failed Stormwater Drains After Heavy Rain Across Auckland

Request A Quote
What's Included

Storm & Flood Plumbing In Auckland

Overflowing gully traps, sewage backing up, blocked downpipes and stormwater drains after heavy rain, found and fixed across Auckland.

  • Clearing overflowing gully traps and checking whether the blockage is on your section or in the public network
  • Clearing blocked downpipes, sumps, channel drains and private stormwater pipes
  • Camera inspection of wastewater and stormwater drains after a storm, with a written report
  • Checking and clearing soakholes and stormwater outlets that have silted up or stopped draining
  • Finding downpipes or yard drains wrongly connected to the wastewater drain
  • Repairing drains cracked or displaced by slips and ground movement, with a drainlayer where needed
  • Photos and a written report to support an insurance claim

Signs You Need To Call Now

  • Sewage or dirty water coming up through the gully trap, a shower waste or the toilet
  • The gully trap overflowing during rain and settling again when it stops
  • Downpipes overflowing at the gutter or spilling at the base instead of draining away
  • Water ponding against the house, under the floor or in the garage after rain
  • A soakhole or yard sump that no longer drains after a storm
  • Toilets and drains gurgling or draining slowly every time it rains heavily

Auckland gets a lot of rain, and every so often it gets far more than its drains can carry. On 27 January 2023, Auckland Anniversary Weekend, the city recorded its wettest day on record, and homes flooded across Wairau Valley, Mt Eden, Kumeū, Henderson and elsewhere. Two weeks later Cyclone Gabrielle brought slips and damage to the west coast and the Waitākere Ranges, and there was more flooding in May 2023. The plumbing side of events like these is overflowing gully traps, sewage coming up where it should not, downpipes that cannot keep up and stormwater drains that fail.

What goes wrong in an Auckland storm

Overflowing gully traps and sewage backing up

The gully trap is the outdoor trap, usually beside the house, that takes waste water from the kitchen, bathroom and laundry into the wastewater drain. In a storm it can overflow for several reasons: your private drain is part-blocked by roots or debris, a downpipe has been connected into the wastewater drain, the gully rim is too low so surface water floods in, or the public sewer is overloaded and pushing back. Sewage coming up through the gully trap is unpleasant, but it is better than the alternative. The gully sits lower than the fixtures inside so that a backed-up drain relieves outside, not through your shower or toilet.

Combined sewers in the older central suburbs

Parts of the central isthmus, including Grey Lynn, Ponsonby, Herne Bay, Freemans Bay, Westmere, Point Chevalier and parts of Mt Eden and Kingsland, are on a combined wastewater-and-stormwater network that overflows in heavy rain. Watercare’s Central Interceptor tunnel, running from Grey Lynn to the Māngere treatment plant, is designed to cut those overflows. Until then, homes in these suburbs benefit most from a correctly set gully trap and a private drain in good condition.

Blocked downpipes, sumps and soakholes

Gutters and downpipes full of leaves from pōhutukawa, oaks and liquidambars overflow against weatherboards and into subfloors. Private stormwater pipes crack where roots find the joints. In areas without a public stormwater connection, roof water goes to a soakhole, and a silted soakhole simply fills up and stops.

Slips and moving ground

Much of the North Shore and West Auckland sits on Waitematā clay, which swells, shrinks and slips on slopes after heavy rain. A slip can crack or pull apart drains, and a leaking drain can make a slope worse.

Who looks after what

  • Watercare owns the public water supply and the public wastewater network, including the sewer your private drain joins.
  • Auckland Council’s Healthy Waters looks after public stormwater: pipes, catchpits, overland flow paths and streams.
  • The property owner is responsible for gutters, downpipes, private stormwater pipes, soakholes and the private wastewater drain up to where it joins the public sewer.

A good plumber tells you which side a fault is on, and does not quote you to fix something that belongs to Watercare or the council.

What to do before the plumber arrives

  1. Stay safe. Keep out of floodwater, stay clear of wet power points and switchboards, and ring 111 if lives are at risk.
  2. Stop using water inside if the gully trap or a floor waste is overflowing. No flushing, showers or washing machine.
  3. Clear gutters and downpipe grates only if you can do it safely from the ground. Do not climb ladders in a storm.
  4. Check the street. If neighbours have the same problem, report it to Watercare or Auckland Council.
  5. Take photos and video before cleaning up. Photos and a written report help with an insurance claim.

How the job is done

The plumber starts at the gully trap and inspection points, working out whether the blockage is private or public. Private drains are cleared with a machine or a water jetter, then a camera inspection shows roots, cracks, bellies or wrong connections. Downpipes and sumps are cleared and checked for proper flow, and soakholes are inspected and cleaned. Where the pipe is broken, the repair is quoted before work starts, and larger drain replacements are planned with a drainlayer once the ground is safe. See blocked drains for more on how drains are cleared and repaired.

When it is not an emergency

A gutter overflowing in a downpour that empties once the rain eases, or a yard that takes a few hours to drain, can wait for a dry-day booking. Sewage coming up, water getting under the floor or into the house, and drains broken by a slip should be dealt with now. For after-hours storm call-outs anywhere in the city, including West Auckland, our 24 hour emergency plumber service is available, and you are given an honest arrival time on the phone.

How It Works

The Job, Step By Step

01

Call

Say what is overflowing and where. You are told what to stop using and what is safe to do, you get an honest arrival time, and the call-out and hourly rate are explained before anyone is dispatched. During a big weather event, the most urgent jobs are triaged first.

02

Find the source

The plumber checks the gully trap, inspection points and downpipes to establish whether the problem is a private blockage, a wrong connection, or the public wastewater or stormwater network being overloaded.

03

Clear and repair

The work is quoted before it starts. Private drains are cleared with a machine or water jetter, downpipes and sumps are cleared, and damaged pipes are repaired or scheduled for repair once the ground is safe to dig.

04

Report

You are shown what was found, told whether any issue belongs to Watercare or Auckland Council, and given photos and a written report that help with an insurance claim.

FAQ

Storm & Flood Plumbing Questions

Why is my gully trap overflowing when it rains?
The gully trap is the outdoor trap where your kitchen, bathroom and laundry waste enters the wastewater drain, and its grate is meant to sit above the ground so rainwater stays out. When it overflows in rain, either your own drain is part-blocked and cannot cope, a downpipe or yard drain has been connected into the wastewater system, the gully rim is too low and surface water is running in, or the public sewer is overloaded. A plumber checks each of those in turn. A private blockage or wrong connection is fixed on your section; an overloaded public main is reported to Watercare.
Sewage is coming up through my gully trap. What do I do?
Stop using water inside: no flushing, showers, washing machine or dishwasher, because every litre adds to the overflow. Keep people and pets away from the area and do not try to clear it by hand. If it is happening across the street or in neighbouring properties too, the public network is likely overloaded and it should be reported to Watercare. If it is only your property, the blockage is probably in your private drain, and a plumber can clear it. The gully trap overflowing outside is actually doing its job, because it releases sewage outdoors instead of inside the house.
My suburb has combined sewers. What does that mean for me?
Parts of the older central isthmus, including Ponsonby, Grey Lynn, Herne Bay, Freemans Bay, Westmere, Point Chevalier and parts of Mt Eden and Kingsland, have a combined network that carries both wastewater and stormwater. In heavy rain it can reach capacity and back up. Watercare's Central Interceptor tunnel is designed to reduce those overflows. At property level, a plumber can check your gully trap height, your private drain and any overflow relief, so that if the network does back up, it spills outside rather than into the house. The public network itself is Watercare's responsibility.
Who is responsible for stormwater, the council or me?
Auckland Council's Healthy Waters looks after public stormwater, such as the pipes, catchpits and streams that carry water through the city. Watercare looks after the public water supply and wastewater network. On your section, the gutters, downpipes, private stormwater pipes, sumps and soakholes belong to the owner, and a plumber or drainlayer maintains and repairs them. A blocked public catchpit in the street is reported to Auckland Council; a blocked downpipe or private drain is yours to have cleared. If the plumber finds the fault is in a public asset, you are told who to report it to.
What is a soakhole and why has mine stopped working?
A soakhole is an underground pit that lets roof or yard water soak into the ground where there is no public stormwater pipe to connect to. They are common in parts of Auckland, including some of the volcanic central suburbs where water can drain into fractured rock. Over time they fill with silt, leaves and roots, and after a very wet period the ground around them may be too saturated to take more water. A plumber can inspect the soakhole, clear the pipes feeding it and advise whether cleaning will restore it or whether it needs rebuilding.
Is a flooded house covered by insurance?
That depends on your policy, and your insurer is the only one who can answer it. What a plumber can do is document the plumbing side of the damage properly. After the January 2023 Auckland Anniversary floods and Cyclone Gabrielle, many homes had damage to drains, gully traps and stormwater systems. Take photos and video before cleaning up, keep damaged items until the insurer says otherwise, and ask the plumber for a written report with photos and camera footage showing the condition of the drains. Photos and a written report help with an insurance claim.
Can you fix drains damaged by a slip?
Yes, but safety comes first. After heavy rain, slips on Waitematā clay slopes on the North Shore and in West Auckland, and on the steep bush sections around Titirangi and the Waitākere Ranges, often crack or pull apart wastewater and stormwater pipes. If the ground is still moving, or a geotechnical engineer or the council has restricted access, repair waits until it is safe. In the meantime the plumber can isolate or divert the damaged pipe to stop sewage or stormwater making the slip worse, and camera the drain to plan the repair with a drainlayer.

Nearby Suburb Guides

Helpful Guides

Water Where It Shouldn't Be?

Turn it off at the toby, then get a licensed Auckland plumber on the way. The rate is explained before anyone is dispatched.

Get A Quote Our Services