Protecting koalas

We’ve reached a milestone in our protection and expansion of koala habitat in south-west Sydney. In June 2024, we planted 20,000 trees and shrubs at our initial project site, with another 20,000 planted in November 2024.

Over many decades, these 10 hectares of protected reserve will evolve from open paddock to open forest and woodland. To ensure that the future habitat can support koala populations, at least 30% of the trees planted are preferred local feed trees, such as grey gums.

As the trees and shrubs mature, they will increase the value and area of protected habitat for koalas in south-west Sydney.

We are installing koala protection fencing between koala habitats and providing safe koala crossings along Appin Road and other linear infrastructure to facilitate koala movement. As part of delivering the CPCP, the NSW Government is building 3 koala friendly crossings in Appin: at Kings Falls Bridge, Ousedale Creek and Upper Canal. The CPCP has also provided funding to install koala protection fencing at key locations.

View the koala protection measures map (PDF, 2.2 MB). 

Kings Falls Bridge

In 2022, we constructed the first koala friendly crossing, at Kings Falls Bridge on Appin Road. This crossing supports the north–south movement of koalas between Warranmadhaa National Park and koala habitat to the south. The crossing was modified in 2025 to make it more appealing for koalas and resilient to vandalism.

We also installed 750 metres of koala protection fencing at this site to keep koalas off Appin Road and lead them to the crossing. Work is continuing to extend the fencing north-west and south-east, on both sides of Appin Road. This fencing extension is scheduled for completion in 2026.

Installing fencing north of Kings Falls Bridge to the north–east side of Appin Village is challenging due to land tenure and site constraints, such as geography and underground utility corridors. Most of this section of road has a low 50km/hr speed limit and on the south–east side is separated from larger roads by suburban housing. Bionet data is regularly monitored to determine if additional fencing or other mitigation actions are needed. This section of road is marked as ‘observation area’ in this koala protection measures map (PDF, 2.2 MB).

Ousedale Creek

Transport for NSW, on behalf of the Department of Planning, Housing and Infrastructure, will be constructing a koala-friendly crossing at Ousedale Creek under Appin Road near Brian Road.

The Ousedale Creek Koala Underpass project follows the advice of the NSW Office of the Chief Scientist and Engineer for the development of an east-west koala corridor. It is part of the NSW Government’s koala-friendly crossings election commitment and will begin construction in 2026.  

In 2023, Transport for NSW exhibited a review of environmental factors for the crossing, and it was determined in July 2025. The design is being reviewed based on feedback received, and construction is scheduled to commence in 2026.

The Office of Strategic Lands has acted to acquire 4 properties to enable construction of the koala crossing and to provide a functional koala corridor by restoring the land as koala habitat.  

Separate to the CPCP, 2 more koala crossings are being installed along Appin Road at Noorumba and Beulah, with koala protection fencing installed between Rosemeadow and Gilead. These projects are associated with the Gilead development.

To learn more about these projects, visit Transport for NSW Appin Road projects.

Upper Canal

WaterNSW, funded by the Department under the CPCP, has installed an over-pipe crossing and 4 under-fence crossings at the heritage-listed Upper Canal. This will support koala movement across the Upper Canal and in the Ousedale corridor. Construction was completed ahead of schedule, in July 2025.

The structures were built to allow koalas to move safely under existing boundary fences in 4 locations where evidence of animal usage, like tracks and droppings, was identified. A lightweight bridge was also engineered and installed over the pipeline, providing an alternate way for koalas and other wildlife to cross the Upper Canal.

Hume Highway, Wilton

With funding from the CPCP, Transport for NSW installed koala protection fencing along the Hume Highway at the Picton Road interchange, and south of Allen’s Creek bridge in Wilton. This project, which was completed in 2024, aims to keep koalas off the highway and guide them safely underneath bridges as they move between habitats.

In partnership with the NSW Koala Strategy, we have developed a 3-tiered program that will assess and monitor key koala outcomes from the Cumberland Plain Conservation Plan.

Regional survey

We monitor koalas in south-west Sydney each year by acoustic survey and drones to establish where they are living and their relative abundance. The regional survey aligns with statewide monitoring under the NSW Koala Strategy. The survey will allow the south-west Sydney koala population to be directly compared with other koala populations across the state.

Disease monitoring

Every 2 years, we monitor the chlamydia status of Campbelltown–Wollondilly koalas. Surveys done in 2021, 2023, and 2025 confirmed that Campbelltown koalas remain chlamydia-free, but that chlamydia is present in the population south of Appin.

Population estimate

Each year, we monitor koalas in Warranmadhaa National Park to track koala densities and the number of koalas present in the reserve over time. The survey will take place every spring using song meters to listen to male koalas calling.

Update on the findings of the koala monitoring program

South-west Sydney Regional Survey

The first survey was completed in spring 2023, followed by the second in spring 2024.

The survey runs for 6 weeks in September to October and includes:

• acoustic surveys to record koala occupancy (where koalas are found)
• drone surveys to estimate koala relative abundance (number of koalas in an area).

Plots are located in a range of habitats including intact and fragmented woodland, high- and low-quality koala habitat, and nearby cleared areas.

What we found

• In the 2023 acoustic survey, koalas were detected at 35 of the 53 plots, mainly in intact woodland on the western edge of the Woronora Plateau, but also on the Nepean River and in fragmented corridors in Greater Macarthur growth area.
• Drone surveys in 2023 detected koalas at 20 of the 46 plots surveyed, with multiple koalas detected at some plots. They were recorded in similar areas to the acoustic survey. The highest numbers of koalas were detected along the Georges River between Kentlyn and Wedderburn, and in the Upper Nepean State Conservation Area.
• The 2024 survey included multiple drone flights per plot to improve koala detection and provide more accurate numbers. Full results of the 2024 survey will be available in 2026.

Disease survey

Every 2 years, we monitor the chlamydia status of Campbelltown-Wollondilly koalas. The survey is an important part of monitoring the prevalence of disease in the koala population in south-west Sydney.

A baseline survey was conducted in 2021, with follow-up surveys in 2023 and 2025. The surveys have been conducted for periods of 2 to 3 months, between April and June, monitoring 19 plots of 140–150 hectares each, between Long Point and Wilton. Koalas are detected using thermal drones and spotlighting, and fresh koala scat is collected from tree bases.

What we found

• In 2023, the survey detected 138 koalas with 129 scat samples collected. Of the verified scat samples, DNA testing identified 96 unique koalas – 46 males and 50 females.
• The chlamydia results showed that 86 koalas tested negative and 10 koalas (mostly males) tested positive. Infections were limited to south of Appin Road.
• In 2025, the disease survey was part of a larger, more intensive survey of south-west Sydney coordinated by the NSW Koala Strategy. A total of 252 koalas were detected and 240 scat samples collected. Of the verified scat samples, DNA testing identified 158 unique koalas – 69 males and 89 females.
• The chlamydia results showed that 151 koalas tested negative, and 7 koalas (4 males and 3 females) tested positive. Infections were limited to south of Appin Road.

Warranmadhaa National Park population estimate

We conduct an annual survey of koalas within Warranmadhaa National Park to estimate the park’s koala population. The first survey took place in 2023.

Acoustic surveys run over 15 days in September to October, calculating the density of koalas in the reserve. Male koala bellows are recorded from sunset to sunrise at 3 locations across the north, south and middle of the park. These recordings are used to estimate koala densities by adding in female koalas at a 1:1 ratio, and accounting for vegetation within the reserve.

What we found

• In both 2023 and 2024, male koala density was estimated to be between 0.05–0.07 males per hectare across the 3 survey locations. In 2024, the population estimate for koalas within Warranmadhaa National Park was 188 koalas accounting for habitat variation and plant communities (range of 142–234 with 95% confidence).
• While this is slightly lower than the 234 koalas that were estimated within the park in 2023 (range of 188–278 with 95% confidence), because the data ranges for the 2 surveys overlap, this is not considered a statistically significant difference.
• The latest survey was completed in October 2025, and the results will be available in 2026.

Acknowledgement

The Department would like to acknowledge the work of the Conservation Program Division of the Department of Climate Change, Energy, the Environment and Water for delivering these surveys on behalf of the Cumberland Plain Conservation Plan.

The CPCP has contributed funding to a range of projects that support the health and welfare of the koala population in south-west Sydney.

Monitoring of koalas released into the wild

Research by Science for Wildlife looked at koala survival after they have been in care to inform current protocols for releasing them. The project monitored 36 koalas for up to 12 months to see how they survived. This project has contributed to better carer procedures and koala release protocols. The CPCP funded the development of an app for wildlife carers that helps them find suitable feed trees for koalas in care.

Vaccine trial for Campbelltown koalas

A research trial led by University of Sydney vaccinated 53 koalas against chlamydia and monitored them over 12 months. While the vaccine produced an antibody effect, it was not 100% effective. Of the 53 koalas, 4 contracted the disease within 6 months of vaccination.

The trial concluded that vaccination alone may not give enough protection against chlamydia and other management actions may be necessary to prevent infection of the Campbelltown koala population.

Koala coordinator for south-west Sydney

The CPCP-funded koala coordinator has delivered major gains for rescued koalas in south-west Sydney, with almost 70 animals treated and released, and stronger support now in place for local carers. 

The 2-year initiative, which kicked off in 2024, improved coordination of treatment and record keeping for all koalas admitted to the hospital and has improved outcomes for both animals and the carers who support them. Following this success, the University of Sydney will continue to fund this role for a further 2 years.

Based at the Wildlife Health and Conservation Hospital at Camden, the coordinator improved relationships with wildlife groups through regular check‑ins, home visits and training workshops. New biosecurity protocols for koala carers and veterinary hospitals were also established, providing clear standards for disease management, including chlamydia risk.