Keep stormwater out of your sewer pipes

Cloud and rain

Or you run the risk of a sewage overflow at your home or business

Most of us don't realise the wastewater and stormwater networks are 2 completely different systems.

They should never connect but in many private properties, they do.

When we inspect homes and businesses, we tend to find 2 things that aren’t right:

  • downpipes that flow into sewer pipes
  • overflow relief gullies in backyards that are too low, or covered up.

When it rains heavily, this can cause sewage overflows in your home or business, down the street or in local parks.

Save yourself the stench and messy clean-up. You'll also help keep the wastewater service you receive from Council safe, sustainable and affordable. Read on to find out how.

Advice on what to do if you have a sewer blockage, overflow or odour is also available.

What to look out for

Your downpipes

Do you know where stormwater from your downpipes goes? It should flow to a stormwater pit in your yard or an outlet on the road out front.

When it next rains, check that your stormwater runs to either of those locations. If it doesn’t, contact us – we’re here to help.

The most important thing to remember is that downpipes should never connect to your sewer pipes. It’s illegal. If yours do, please fix this as soon as possible.

Storm safe pipes

The downpipe on the far left is illegal – it directs stormwater to the home’s sewer pipes, which can cause nasty sewage overflows when it rains. It’s been fixed, as shown on the right. Photo credit: Unitywater

Your overflow relief gully (also called a yard gully)

Do you know where your overflow relief gully is?

It's a very important piece of plumbing because it helps prevent nasty sewage overflows inside your home when it rains heavily.

To do its job, your overflow relief gully must:

  • have a light, grated cap that can pop off completely when it overflows
  • be at the correct level - typically 150 mm lower than the lowest fitting in the house (e.g. a toilet bowl, shower or floor drain) and usually 75 mm above the surrounding ground.

Also, it must not be covered:

  • with concrete or paving
  • by landscaping, garden beds or other objects - we commonly see mats and pot plants on them.

Check your overflow relief gully today! It's outside, usually near your kitchen sink or laundry.

If it's not compliant, get it fixed. Contact us for free advice.

Overflow relief gullies

Left is an overflow relief gully that didn't meet the standard. Whenever it rained, stormwater flowed through the gully into the homeowner's sewer pipes, which could have caused a sewage overflow inside.

On the right is the same gully fixed by a licensed plumber. It's now 75 mm above ground, preventing stormwater that pools on the ground from entering it. Also, the gully is clear of any debris or covering (keep those mats and pot plants off!).

More ways to prevent problems

  1. Never plant trees over or around your property's sewer pipes.
  2. Repair broken pipes on your property immediately.
  3. Know where your boundary shaft is - this is the connection point to the public sewer. If there's a sewage overflow at your home and the shaft is full, it's Council's problem to fix.

What Council is doing

Each year, our crews work hard to detect how stormwater enters the Tweed's wastewater network.

We focus on locations where data indicates there:

  • is a lot of stormwater inflow
  • are sewage overflows whenever it rains heavily.

Sometimes, we undertake smoke and dye testing, and put cameras inside sewer pipes to pinpoint where stormwater enters.

If we come across an illegal or inappropriate stormwater-to-wastewater connection on a private property, we inform the property owner and advise them about the work that's required to fix it.

When we detect problems on our side of the wastewater network, we fix them. Most commonly, we reline older sewer pipes and fix leaky manholes.

Smoke test

To detect how stormwater enters the wastewater network, we sometimes use smoke. Our smoke testing program involves blowing non-toxic smoke into the wastewater network and keeping an eye out for where the smoke escapes.

Safe, sustainable and affordable water and wastewater services