What Is An Overflow Relief Gully And What Does A Blocked ORG Mean?

blocked ORG what you need to know about Overflow Relief Gullies

If you have a blockage on your property, chances are you have a blocked ORG. Here’s what you need to know about Overflow Relief Gullies (ORG) and what you can do before you call the plumber.

On Saturday morning, while I was cleaning the house to get it ready for Esther’s Shopkins party later that afternoon, I noticed the water from the sink was taking a lot longer to drain.

A quick inspection outside and I noticed our overflow relief gully (ORG) was full of water.



blocked org

Which meant one thing. We had a blockage. But what was the blockage caused from? Too much paper down the toilet or had someone removed the grate and decided to fill it with rocks?

It seems the latter was the culprit.

Maggie had taken off the grate and filled the drain up with surrounding rocks that we have on the side of our house.

The only way to unblock it was to get my hand and arm down there and pull out as many rocks as I could reach from the bottom of the trap.

I quickly changed out of my pj shirt, put on a tankini singlet and grabbed a latex glove to prevent breaking off one my fake nails. I honestly didn’t care about the look, but I did care about the pain. I don’t know how many times I’ve nearly ripped one of the nails off my fingers. I was taking no chances with the rocks!

I then reached down as far as I could go to scoop up the rocks from the ORG. There were a fair few of them and the brown water reached up to just below my shoulder. It stank and had sediment which was a little gross but not as gross as some jobs I’ve been on.

I got as many rocks as I could and was able to unblock the ORG. There were still some I wasn’t able to reach though.

What is an Overflow Relief Gully? (ORG)

I’ve written about ORG’s on the blog before but not a lot of people know about them and so I thought I’d share a bit more information on them.

All properties in Australia require an Overflow Relief Gully (ORG). It’s simply a grated drain that acts like a relief valve, located outside (usually outside the laundry or kitchen) that prevents a blocked sewer emptying its contents into your home. An ORG has a grate that pops out and allows the sewerage to overflow freely outside if you have a blockage in your plumbing.

org diagram
Diagram via Power Water

Usually the ORG is at least 100mm (although Queensland Urban Utilities state 75mm) lower than the lowest waste outlet in your home (eg. basin, shower or toilet) and at least 150mm above the surrounding ground to prevent storm water flowing into it.

It’s really important to inspect your ORG every so often to make sure that it’s not full of water (which means a blockage) and that it hasn’t been covered up. Downpipes and storm water should not be connected into the ORG as it can back up the sewer system which is not designed to carry storm water.

Houses built pre-1976 won’t have an ORG, but if it’s been renovated or you’re looking to renovate the house, the plumbing council won’t approve plans unless the plumbing has been brought to code and an ORG is installed. To be honest, I wouldn’t live in a house without one. No house is ever immune to a plumbing blockage so to not have an ORG on your property means you could find yourself with a nasty mess to fix up and an insurance claim. It’s a stinky debacle you really want to avoid.

In my situation, I have to tell my girls NOT to fill our ORG with rocks. I think Maggie got the message last Saturday when she saw the colour of my arm and wrinkled her nose asking why I smelt.

Brown ORG Arm

Miss Maggie, I smelt because of you!

One thing to do after reading this post is locate your ORG and check that the grate is installed properly and that there isn’t a high water level. If the ORG is full of water, you may find you have a blockage down the line or it’s been filled with foreign matter that shouldn’t be there.

If the fixtures in your house don’t drain properly, a quick inspection of your ORG will tell you if the blockage is on the main sewer line or just the pipework from that particular fixture. If the ORG is clear, this indicates the blockage is in the pipework to the fixture itself.

I recently had to get Salmon Plumbing out to use a scoop tool to remove the remaining rocks I wasn’t able to retrieve. A blocked ORG is not going to be an issue anymore.

scooping rocks from blocked ORG

Do you know where your ORG is located on your property? Ever had a blocked ORG?