Plumbing after a flood in Byron and Ballina shires

After a flood, treat any gas appliance, hot water unit, septic or treatment system and rainwater tank that floodwater reached as unsafe to use until it has been checked. Start with safety: keep gas and power off where they were turned off, do not drink tank water that floodwater touched, and photograph everything before cleaning up. Then get a licensed gasfitter, plumber and electrician to inspect the items that went under, in that order of risk.

This guide lists what to check, why, and what records an insurer is likely to want. It is written for Byron Shire and the northern part of Ballina Shire, using the 2022 flood as the local reference. Byron Bay Plumber is a referral service: the inspection and any repairs are done by the independent local business that takes your enquiry, as the about page explains.

What happened to homes in the 2022 flood?

According to the NSW SES Byron local information page, the Brunswick River reached 4.97 m at Mullumbimby, inundating large parts of the town, and height records there go back to 1954.

Figures the NSW minister gave to a parliamentary question, reported by The Echo in October 2023, put the number of flooded homes in Byron Shire at 817. Of those, 468 were in Mullumbimby. The same answers said 188 homes had between 300 and 1,500 mm of water inside, deep enough to reach appliances and controls that stand on the floor. The Mullumbimby area page covers that town.

Byron Shire Council notes that the Shire has high annual rainfall and that floods can happen at any time, most often in the summer wet season. The checks below apply after a smaller event too.

What should be checked first, and by whom?

Item	Main risk after flooding	Who checks it
Gas appliances, regulators and LPG cylinders	Gas leak, damaged burner or flue, moved cylinders	Licensed gasfitter
Electric or heat pump hot water units	Water in the wiring, element or controls	Licensed electrician, then a plumber
Septic tank or treatment system	Overflowing tank, flooded disposal area, wet electrics	Plumber or service agent, plus an electrician for the pump and blower
Rainwater tank and pump	Contaminated water, damaged tank or pipework	Plumber, tank cleaner, electrician for the pump
Drains, gullies and inspection points	Silt and debris causing blockages	Plumber or drainer
Stormwater pits and downpipes	Blocked grates and pipes, scoured outlets	Plumber

What do I do about gas appliances that went under?

Only a licensed gasfitter may repair, move or replace a gas appliance in NSW, so leave any heater, cooktop, hot water unit or barbecue connection that sat in floodwater switched off until one has looked at it. Floodwater can leave silt in burners, controls and regulators, and cylinders can be shifted or tipped by moving water.

If you smell gas when you return, follow the safety steps on the gas fitting page, which sets out what to do before anyone touches the appliance. After the gasfitter has checked or repaired an appliance, ask for the certificate of compliance or inspection for that work and keep it with your claim papers.

Can I use the hot water unit again?

Not until it has been checked. An electric or heat pump unit that sat in water may have wet wiring, a damaged element or ruined controls, so an electrician should test it before the power goes back on. A plumber then checks the valves, the relief valve drain and the tank base, which can move when the ground underneath is saturated. A gas unit needs the gasfitter check above as well.

Where a unit has to be replaced, the hot water comparison sets out the options. Replacing an existing hot water system is minor work that needs no Notice of Work to the local regulator, and once the new unit is in, ask the plumber for your copy of the compliance certificate for the claim file.

How are drains and overflow relief gullies affected?

Floodwater carries sand, silt and garden debris into open gullies, pits and any cracked pipe. Common signs after an event are slow drains, gurgling, and water sitting in the overflow relief gully or the yard. Lift the grate on the gully and clear any debris you can reach. Building Commission NSW’s advisory note on overflow relief gullies says the gully must sit at least 75 mm above finished ground, so a gully left buried under deposited silt should be dug out.

If a drain keeps blocking after the clean-up, ask for a camera inspection. It shows whether silt is still sitting in the line or the pipe has cracked or shifted, and the recording supports an insurance claim. Roof water, downpipes and absorption pits are covered on the stormwater and drainage page.

What happens to a septic or treatment system in a flood?

When the disposal area is under water, effluent has nowhere to go, and a tank can fill with floodwater and silt. Byron Shire Council’s on-site sewage page lists leaks, soggy ground and unpleasant odours as common signs of a problem, and says owners are responsible for repairs. After a flood, those signs can last for weeks.

Steps to take:

1. Use as little water as possible until the ground has drained, so the system is not pushed further.
2. Keep people and pets off a disposal area that is still wet.
3. Leave the power off to an aerated treatment system until an electrician has checked it. Council’s page says all electrical work on these systems must be done by a licensed electrical contractor.
4. Have the tank, pump, blower and alarm checked by a plumber or service agent before normal use resumes.
5. If parts of the system need replacing or altering, Council approval may be needed.

The septic and on-site sewage page explains how those systems are serviced and repaired.

Is rainwater tank water safe after a flood?

NSW Health’s guide to cleaning rainwater tanks after floods or storms says tanks affected by floods and storms are likely to contain harmful microorganisms, so the water is not suitable for normal use. It also says not to use the water where the tank or pipework is damaged, or where floodwater has touched taps or connections. Bring drinking water with you when you return home.

The same guidance says:

• only empty a tank if floodwater actually got into it;
• emptying a tank before the surrounding ground has dried can damage the tank and its plumbing;
• have a licensed electrician check any pump or electrical equipment you suspect was affected;
• use a professional tank cleaner if anyone would need to go inside the tank;
• check the plumbing, gutters, downpipes and roof, which also need cleaning and disinfecting.

The rainwater tanks and pumps page covers reconnecting a pump and repairing tank plumbing.

What records help an insurance claim?

Insurers set their own requirements, so read your policy and ask your insurer. Records that are generally useful:

• Photos and video of each damaged item before it is moved or cleaned, with something in shot to show the water line.
• A list of each item, its brand and model, and its approximate age.
• Written reports from the gasfitter, electrician and plumber stating what they found and what they recommend.
• Camera footage of drains, if a camera was used.
• Receipts for any emergency work, and copies of compliance certificates for repairs.

Ask each provider to put their findings in writing, and keep a copy of every certificate with your property records. Every repair to gas, plumbing or drainage must be done by a person holding the right NSW licence, and the about page shows how to confirm that before work starts.

Next step: list what the water reached

For a post-flood check, list each item that was in the water: gas appliances, hot water unit, septic tank or treatment system, tank and pump, and any drains that are now slow. Give the depth the water reached inside and outside if you know it, say whether the power and gas are currently off, and attach photos of each item. Then send a flood damage plumbing enquiry so the provider can plan which trades need to attend first.

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