Check your gully traps

What is a gully trap?

A gully trap is an outside drain or basin that collects all the used water from inside your home – including sinks, showers, basins, and washing machines – before it flows into our wastewater network. Every house has at least one gully trap and you’ll usually find it against an outside wall near your kitchen, bathroom or laundry.

What is the purpose of a gully trap?

Its primary function is to act as an external overflow point to prevent wastewater from backing up inside your home during a blockage. Gully traps also include a water seal to block any wastewater odours from getting inside your home.

The New Zealand Building Code has specific requirements for the installation and location of gully traps.

Does your gully trap measure up?

By ensuring your gully trap is compliant – that is properly installed and maintained – you’re helping to protect your own home and property, and the wider wastewater network and environment.

If it is damaged, blocked, too low to the ground, or connected incorrectly, rainwater can get into the wastewater system and overload the system. If this happens, wastewater can back up onto your property, inside your house or contribute to overflows elsewhere in the network.

Things to look for in a compliant gully trap

Things to look for in a non-compliant gully trap

How to check and maintain your gully trap

Property owners are responsible for maintaining private drainage, including gully traps, on their land. Some regular checks and simple maintenance, along with ensuring compliance with the building code, will help to prevent problems.

Check regularly: Ensure your gully traps are clear of any leaves, dirt and debris and in good condition.
Fix damage early: Look out for cracks, broken pipes or loose fittings around your gully trap/s as they may need to be re-sealed or replaced periodically.
Ensure it's raised and covered: Make sure your gully traps are raised off the ground and covered with a grate to prevent ground water, surface water and other foreign items from entering the wastewater network.
Keep stormwater out: A gully trap should never be connected to downpipes from your roof or any other stormwater run-off. Wastewater and stormwater are two separate networks, and it is the property owner’s responsibility to ensure they stay that way.

Need help or advice?

If you notice damage or signs of a blockage, or need assistance to carry out checks of your gully trap, contact a licensed plumber.

For general advice, contact Taupō District Council on 07 376 0899 or 0800 ASK TDC (0800 275 832).