After heavy rain, Adelaide’s River Torrens / Karrawirra Pari can get a bit polluted. Read on to find out some of the unusual items spotted – plus discover what’s being done to keep the river clean.
When it rains, water collects rubbish and other pollutants from roofs, streets, footpaths and driveways.
That rainwater run-off – or stormwater – is unfiltered, and everything it picks up including rubbish is carried with it into our waterways, either directly or through Adelaide’s stormwater system.
But sometimes items are illegally dumped in or on the banks of our rivers and waterways too.
Here’s 5 things you might not expect to have found their way into the river:
- Shopping trollies
- BBQ gas bottles
- Eskies
- Wallets
- Prams
Unfortunately most of these items are illegally dumped.
Now we’ve got your attention about the whacky things found in the river, let’s get to the important stuff:
What’s being done about trash in the Torrens?
Items dumped in the Torrens aren’t the only problem – some trash gets inadvertently swept into waterways too.
We use gross pollutant traps – trash racks, sediment basins and floating booms – to help keep rubbish out of the River Torrens/Karrawirra Pari. Some of these are on the river itself, while others are on waterways that feed into the river, such as First Creek.
Trash racks are essentially a rubbish net, while floating booms lay on top of the water, helping trap floating material when there are ‘high flows’ – a phrase that basically means lots of water in the river. Sediment basins help collect the fine material – such as silt – carried in the water.
Together, these collect a lot of rubbish that would otherwise flow down the river and out to sea.
Here’s how much trash we pulled out of the River Torrens in the last 4 months:
2023 | Tonnes | Equivalent to… |
April | 25 | 70+ average professional grand pianos. |
May | 29 | at least 18 midsize cars, such as a Toyota Camry or Mazda 6. |
June | 124 | not that much less than the lightest Boeing 747 aeroplane (they weigh about 153 tonnes). |
July | 56 | more than the largest adult humpback whale. |
How often are trash racks cleaned?
There is a comprehensive cleaning program in place for gross pollutant traps along the River Torrens / Karrawirra Pari and waterways that feed into the river.
Our trash racks, floating booms and sediment basins are visited at least once every 3 weeks – and more often when there is higher rainfall.
Why can’t all rubbish be collected in trash racks?
Green Adelaide is responsible for the cleaning and maintenance of 6 trash racks and 1 floating boom along the River Torrens / Karrawirra Pari and connected waterways. Local councils also operate other trash racks and systems to remove rubbish from the river.
Trash racks must be used strategically because they can impact on animals that live in the river – for example fish that need to migrate as part of their lifecycle.
They can also be a risk during flooding, when water is flowing quickly, and they may be completely submerged and therefore hidden. So unfortunately, putting more of them in the river isn’t always the best solution – or even an option.
How can smaller objects be collected from the river?
Because of the size of the nets, trash racks don’t collect smaller items.
Floating booms and sediment basins help us get some of the harder to collect things out of the River Torrens / Karrawirra Pari. Trash racks are designed to catch larger things and organic materials – they don’t capture things like bottle lids.
To collect things this small, trash rack nets would need to have smaller holes, which would get blocked quickly and not let enough water flow through. That may also impact animals living in the river, that need to be able to move up and down stream.
The best way to keep rubbish out of the river is to stop it getting in there in the first place.
Can you drain the Torrens and clean it out?
No. Draining the River Torrens / Karrawirra Pari would negatively impact the ecosystems along the river and the creatures that live in it.
Who is responsible for trash in the Torrens?
Everyone can play a part in keeping trash out of the River Torrens / Karrawirra Pari and other waterways.
Once it’s in the river, it’s the responsibility of the landowners to remove it.
There are many landholders for the River Torrens / Karrawirra Pari including local councils, state government, private landholders and commonwealth land.
How can you help?
Stopping trash and other pollutants before it reaches the River Torrens – and needs to get fished out – is the key. It doesn’t matter how close you live to a waterway, what you do at home can make a difference.
Soaps, chemicals and other home and garden items can negatively impact plants, animals and water quality. Here’s how you can help keep pollutants like these out of our waterways:
- Avoid or minimise the use of fertilisers, herbicides, and pesticides.
- Wash your car or equipment on a grassy or gravel area to avoid soaps (even the biodegradable ones) ending up in the gutter.
- Cover any exposed piles of construction material or soil.
- Collect any fallen leaves and put them in your green bin.
- Pick up rubbish on the street and in parks, where it’s safe to do so.
- Wait until the last possible moment to put your rubbish bin our for collection if you know there is going to be a storm, so that you bin doesn’t get knocked over and rubbish spills out into the gutter.
- Choose local native species for your garden, as they naturally filter water before it reaches our waterways.
If you have a waterway on or near your property, there are more ways you can help keep our waterways clean.
Main image: Canva.com.