Retired ecologist Bob Crombie and DCCEEW’s Kylie Madden at the TfNSW and DCCEEW Cawleys Bridge project. Photo: Alex Pike, DCEEW.
You might have noticed it on your commute to Sydney – a lot of bustle around an old bridge between Helensburgh and Waterfall.
Cawleys Bridge isn’t getting an upgrade in the traditional sense of the word, however.
As a maintenance bridge, it’s designed to allow fire trucks access during a bushfire, or maintenance trucks access to the railway line.
It’s also used regularly by cyclists and bushwalkers, but its size and scope is much bigger than strictly necessary for its users.
Now it’s being transformed in the hope it will attract some very special new travellers.
Ecologist Kylie Madden lights up when she talks about the project.
“In the 1970s rangers and the community came up with the idea Cawleys Bridge could be retrofitted so you could still get those essential vehicles across but make it possible for animals to use it as well,” she said.
“I’m not a young person, but this idea is older than I am and it’s finally come to fruition.
“Logs, ropes and native plants will help animals like koalas, possums, gliders and wombats make their way between the Royal National Park (RNP) and Heathcote National Park.
“I’m really hoping by having these trees, grasses and shrubs they can hide in they will feel safe and it will be an attractive way to move from one side to the other.”
Kylie works for the Department of Climate Change, Energy, the Environment and Water (DCEEW), which with Transport for NSW (TfNSW), is leading the project.
A Wollongong bush regeneration team will plant more than 700 natives along the bridge, and tree trunks from the Mount Ousley Interchange project are being used to line the structure.
There will also be wing fencing on either end to help funnel animals onto the bridge.
Kylie said the M1 presented a massive barrier for native animals on either side, and had led to populations in Heathcote and the RNP becoming isolated and vulnerable.
There are also a significant number of road deaths from animals trying to make it across, including 10 koalas killed on the M1 over the past five years, two of them not far from the bridge.
She said a lack of cover meant crossing the bridge was just as intimidating to many animals as crossing the road. She has high hopes the project will make all the difference.
“We’ve had cameras up on the bridge for months and only a couple of goannas have used it,” she said.
“We have healthy koala and wombat populations in Heathcote, but virtually none in the RNP.
“We know they want to get across, but very few of them make it.
“Deer fence along RNP makes it really tricky for animals too, but if we are going to have resilient populations we need these areas to be connected.
“It’s inevitable we will have things like disease outbreaks or big fires, so we need the population spread across landscape to allow nature to be resilient.”
It’s an approach that’s been successful in Europe, the US and Canada, and if it works here it could act as inspiration for more wildlife crossings across NSW.
The bridge will be monitored intensively after its revamp is complete to see what works and what doesn’t.
Director of Statewide Services at TfNSW Matthew Burns said other types of crossings had had a positive impact.
“Transport has observed more than 25,000 animals across 67 native species use our crossings throughout NSW, so these structures are having a major positive effect,” he said.
“Transport has delivered more than 300 fauna safety structures across the state but this is the first retrofitted crossing we’ve installed and it maximises value by repurposing part of the existing bridge.
“We will be analysing outcomes closely to decide whether to retrofit other infrastructure, but butterflies have already started using the structure to cross the motorway even before it has been completed, so this is definitely a promising sign.”
As a public space it also provides everyone in the community the opportunity to see what environmentally-friendly infrastructure can look like up close.
Kylie said the response so far was very supportive.
“We’ve had the cameras up for months, and there were concerns they would be stolen,” she said.
“Rather than bolt them to the bridge we put up a sign with a picture of a koala I drew by hand saying, ‘Wildlife camera, call this number if interested’.
“No one has messed with the cameras – people come up and look at them, they’re curious and thoughtful and it restores your faith in humanity.
“It’s such a positive project; it just makes you feel good and I hope it gives people a big smile on their face when they drive underneath it.”
The project is expected to be complete by March, weather permitting.
