Koalas and resilient habitat around Sutherland Shire

Koala spotted in Engadine, July 2020 – photo credit Brian Everingham

Koalas have been seen around the Sutherland Shire over the last few months at Sandy Point, Gymea, Engadine, in the Royal and Heathcote National Parks, and surrounding reserves. 

It’s wonderful we have koalas in and around Sutherland Shire, and exciting. We also need to take care they are protected.

A report from the NSW Legislative Council inquiry Koala populations and habitat in New South Wales has found koalas could become extinct in NSW by 2050 without urgent government intervention. 

That report recommended State government ‘urgently prioritise the protection of koala habitat and corridors in the planning and implementation stages of urban growth areas’.  It notes that wildlife corridors ensure ‘safe connectivity between habitat areas’ and are ‘essential for the survival of koalas.’ They allow animals to move freely over the landscape, find mates, build genetic diversity, escape difficult conditions, and maintain populations at viable levels.

Sadly quite a few koalas have been killed on the roads around the Shire. Unfortunately important wildlife corridors between our national parks are blocked too – the Princess Highway and the F6 act as 30-40m wide barriers.  The South Coast train line adds another 25m to that distance.

Reproduced from Mosley: The First National Park, with the inclusion of a new, potential overpass site near Loftus.

Wildlife corridors are recognised as critical to the survival of many native species, and the wildlife corridors in the image on the right have been known to the National Parks and Wildlife Service for decades.

Yet our wildlife corridors are blocked by barriers. Does it have to be this way?

A number of underpasses and overpasses between national parks have been incorporated as part of the Mona Vale Road upgrade, so there are local Sydney precedents. It’s reasonable to expect such measures would be put in place to protect the biodiversity of Australia’s first national park, and we’ve stressed this point in our submission to the new draft plan of management for the Garawarra State Conservation Area, Royal and Heathcote National parks.

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Koala sightings near the Shire to 4 May, 2021 – www.bionet.nsw.gov.au

Wildlife corridors are not just needed between our parks, but also to prevent koalas from being killed on other roads. The diagram to the left has little red triangles which represent koalas that have been seen around the Shire. It’s amazing and wonderful there are so many. Unfortunately many of the sightings on roads are fatalities.

Over the last year we’ve put in submissions to Sutherland and Wollongong council, have written to State MPs, met with representatives from State government agencies, including the NSW Koala Strategy team and TransportNSW. We’ve also been liaising with a number of other local environmental groups, working together to build the call for action.

We’re now hopeful that as as a result of this advocacy underpasses will be put in at Deadmans Creek at Sandy Point, and at Heathcote Road Bridge when the bridge widening project there begins.

It’s still grim and disappointing government agencies seem to take so long to do anything when koalas continue to be killed and injured.

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The following section provides more detail about zones where koalas protections could be put in place in the Sutherland Shire, and down to Helensburgh. 

Four main locations are identified in this proposal – including “kill zones” along Heathcote Road:  protective measures could be put in place at Deadman’s Creek at Sandy Point; at the Lucas Heights precinct; and around Heathcote Road Bridge over the Woronora River. 

Cawley’s Bridge near Helensburgh crosses the F6 Freeway at Garawarra, is no longer used as a public road, but remains a service road for various agencies. This bridge could be easily be transformed to offer a critical wildlife corridor giving native animals safe passage from Heathcote National Park and the Woronora Special Area catchment through to the Garawarra State Conservation Area and on to the Royal National Park. Ideally the NSW government would be encouraging National Parks management to investigate the feasibility of developing wildlife crossings at a range of locations.

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Proposed repurposing of Cawley’s Bridge at Garrawarra as a wildlife corridor over the F6 Freeway

Cawley’s bridge can potentially allow native animals safe passage over the F6 from Heathcote National Park and the Woronora Special Area catchment through to the Garawarra State Conservation Area and on to the Royal National Park.  The Royal National Park has become increasingly isolated from surrounding natural lands. Some species originally found in the Park are now locally extinct.

Repurposing Cawley’s bridge into a wildlife overpass can be done for relatively minimal cost.  One lane of the service road could be retained: it may only be necessary to convert one side of the bridge into suitable wildlife habitat crossing.  Sheltered walkways could be built on the bridge rails for the use of arboreal species and connected to nearby trees to allow wildlife to safely access the crossing.

The Compton Road overpass in South-East Queensland provides evidence that Cawley’s bridge could be successfully transformed in this manner.

Compton Road is a major east-west arterial road similar to the F6.  In the 10 years since the completion of the land bridge there, only 3 mammals have been killed from motor vehicle accidents. Before this, 5 were killed on this road every month.

Compton Rd rope ladders

The overpass at Compton Road is planted with locally sourced vegetation making a seamless connection to the surrounding forest. It features rope ladders for possums, poles for gliders and customised culverts to act as tunnels for small animals to pass beneath the road.

Rope ladders are important for arboreal animals such as gliders. Greater Gliders were thought locally extinct in the Royal National Park following the horrific 1994 bushfires. The wonderful news is that they have recently been seen again, so there’s now been at least three sightings over the last ten years. The population may still be too small to survive, but at least we have hope. Anything that could be done to sustain the population and build genetic diversity would be valuable.

With Compton Road, another important component of the wildlife crossing is adjacent fencing which funnels wildlife towards the safe crossings, away from busy roads.

This customised fencing is 2.48m, much higher than regular road fencing. This stops animals such as wallabies and kangaroos from gaining easy access. Metal sheet strips deter climbing animals such as koalas and possums. The project has apparently been used to guide best practice designs at a number of major road construction approvals across Australia, and is now industry standard for roads incorporating wildlife management measures.

The Compton Road overpass is a model for what can be achieved with wildlife overpass crossings and has been duplicated across Europe, with seven overpasses in Sweden alone.

In addition to Cawley’s bridge these measures would also be easy to implement along Heathcote Road at Sandy Point, the Lucas Heights Precinct, and Woronora Bridge with the forthcoming upgrades there.

See this Gardening Australia YouTube video ▼ for an overview of the Compton Road overpass – and what could be possible at Cawley’s bridge across the F6

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At Cawley’s Bridge – the great division of the natural landscape and obstacle to wildlife movement presented by the F6 freeway

Cawley’s Road bridge view looking south from the bridge
Cawley’s road bridge viewed from the east side

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Sandy Point – the Deadman’s Creek kill zone

The Sandy Point kill zone – www.bionet.nsw.gov.au

A significant number of koalas and other native species have been killed at Deadman’s Creek at Sandy Point, with confirmed reports of at least 6 koalas killed in 2018 alone.

The Holsworthy military training base provided a relatively safe habitat for koalas but this area was devastated by fire in 2018.  Clear-felling of koala habitat at the Moorebank Intermodal Site and the relocation of the new Army Logistics site on Moorebank Rd has further jeopardised koala habitat around the area, forcing them to seek alternative food sources. 

The Appin, Mt Gilead and Wilton areas appear to be increasingly subject to urban expansion.  Providing safe corridors away from these zones should be made a priority.

The recent parliamentary inquiry report recommended the government ‘urgently prioritise the protection of koala habitat and corridors in the planning and implementation stages of urban growth areas’. 

With the koala kill zones at Heathcote Road, flashing lights and signs warning motorists are inadequate to address the road kill, as is the currently existing fencing.

A Sandy Point resident spotted this koala mother and baby on the road in September 2020. These two survived the crossing but there were two koala killings at the Deadmans Creek kill zone that month.

 An underpass already exists at the new bridge at Sandy Point which could be modified to allow safe passage for these koalas. 

As with Compton Road, directional fencing could be installed to act as a funnel directing wildlife towards this underpass.  Rope ladders for possums and poles for gliders could be installed overhead.  Local Aboriginal land holders to the east of the road and the Ministry of Defence on the western side may need to be consulted in order to obtain permission for this fencing to be installed. The Department of Roads and Sutherland Shire Council would also need to approve this work.

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Lucas Heights and Heathcote Road bridge at Woronora River

The New Illawarra Rd at Lucas Heights has unfortunately become another kill zone at the same time as new housing estates have been developed around the area, putting pressure on the existing koala population.

The Heathcote Road bridge over Woronora River upgrade is expected to result in road closures for at least 6 months.  Regardless of what final decision is reached regarding the character of the upgrades, the closure and associated roadwork offers an ideal time to install koala friendly wildlife crossing and fencing.   These measures could be implemented at both the new Lucas Heights Innovation Precinct, and around the Heathcote Bridge across Woronora River.

The Heathcote Road bridge at Woronora

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The devastating fires over the last year have wreaked a terrible toll on our native animal populations; in relation to koalas specifically the NSW Legislative Council inquiry has advised government urgently needs to assist in protecting remaining populations in order to conserve habitat. 

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Koala spotted in the Royal National Park, April 2021
Engadine koala, April 2021, photo Sharon Redman

For more information or to help with this campaign contact Dr Catherine Reynolds – catherine@ssec.org.au or 0424 644 144

Further reading

A koala on the side of Heathcote Road, Xmas 2020. Photo credit: Jesse Campbell

1 May, 2021 “New documentary film tells story of koalas on Sydney’s southern and south-western fringe” The Leader

10 April, 2021 “Sydney’s hamlet tragedy: urban sprawl conquers all” The Sydney Morning Herald

22 February, 2021 “Submission to Transport NSW regarding the Heathcote Road Bridge Widening Project”

6 February, 2021 “‘How good were koalas?’: A national treasure in peril” The Sydney Morning Herald

19 December, 2020 “Reuben may be heading to the shire for Christmas” The Leader

27 October, 2020 “Destruction of Appin koala habitat a disgrace” The Sydney Morning Herald

1 October, 2020 “Koala carnage on Sutherland Shire roads continues” The Leader

30 September, 2020 “Video of mother and baby koalas on Heathcote Road to add pressure for protection measures” The Leader

21 September, 2020 “Fence-off the koala kill spots, environment groups say” The Leader

6 August, 2020, A koala found in Kirrawee – captured and released in the Royal National Park: “Rescue koala fitted with tracking device before being released in Royal National Park” 7NEWS Sydney

10 July, 2020, “Renewed calls to protect koalas who move through area from upper Georges River to shire’s western fringe” The Leader

May, 2020 Protecting Sydney’s Macarthur Koala Colony – The Survival Plan, Total Environment Centre

20 February, 2020 “Analysis: Koalas: new laws – old tricks”, Environmental Defenders Office

18 February, 2020 “Bushfires hastening NSW koala extinction” The Leader

16 January, 2020 “Sylvania Veterinary Hospital helps nurse injured koala back to health” The Leader

Saving Wildlife – the Compton Road effect, Griffith University https://www.griffith.edu.au/research/impact/compton-road-wildlife-corridor

Wildlife Crossings supported by the NSW Roads and Maritime Services – ‘Gliders take the high road: Study proves highway fauna crossings are being used by threatened species’, ABC News, 19 July, 2018

Dean Karas, 2018 “Scoping for potential wildlife crossings for koalas and marsupial gliders in the Sutherland Shire and Campbelltown regions of New South Wales, Australia” University of Wollongong Thesis Collection

Wildlife Movement Solutions Brisbane City Council https://www.brisbane.qld.gov.au/clean-and-green/natural-environment-and-water/biodiversity-in-brisbane/wildlife-in-brisbane/wildlife-movement-solutions

3 October, 2018 “Six koalas killed on Heathcote Road in last year sparks call for action” The Leader

27 September, 2017 “Rare sighting of koala mother with her joey in Heathcote National Park” The Leader

26 July, 2016 “Koalas tunnels and bridges prove effective on busy roads” Brisbane Times

VicRoads Fauna Sensitive Road Design Guidelines, 2012

11 September, 2013 “Injured koala rescued on Heathcote Road”, The Leader

CSIRO Wildlife Research 30(5), 04 December 2003, ‘Cutting the carnage: wildlife usage of road culverts in north-eastern New South Wales

Spot the koala, Royal National Park, January 2020 – photo credit – Audley Boatshed

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