Source : Perth Now news
Temporary speed limit reductions could be rolled out on busy Cockburn roads to protect vulnerable nesting turtles.
Cockburn councillors voted last week to trial a 10km/h speed limit reduction on Hope Road, Progress Drive and Bibra Drive during the 2027 turtle nesting season from September to December.
A city-first turtle underpass will also be considered at Progress Drive, providing a specialised wildlife crossing beneath the road for turtles to avoid vehicles. The city will clarify with Main Roads WA whether this project could be funded through the Bibra Lake urban road safety program.
However, local environmental group Walliabup Wildlife Warriors told councillors while they were pleased to see steps being taken to protect the turtles, they didn’t believe the city’s proposal was “strong enough”.
“Walliabup Wildlife Warriors support any genuine effort to reduce turtle road mortality at Bibra Lake. However, we believe the city proposal actions can be strengthened, accelerated, and better aligned with evidence-based mitigation,” member Rina Burrows said.
“Speed reduction alone has not prevented turtle death. Hope Road was reduced from 70km/h to 60km/h in February, but volunteers continue to collect dead turtles from the same location every month. It is unreasonable to expect volunteers to patrol roads around the clock without a target solution.”
Ms Burrows said volunteers have recorded more than 550 adult turtle deaths across Beeliar Wetlands since 2023, with ongoing road mortality threatening the species’ long-term survival.
She suggested an alternative solution to trial an automated LED sign activated during rainy weather conditions known to trigger turtle movement. The solar-powered sign would read ‘caution, turtle out – slow down’ to remind drivers to be alert, and automatically switch off when the rain stops and barometric air pressure stabilises.
She said WWW had secured a private sponsor willing to cover the full $10,000 cost, meaning there would be no financial pressure on ratepayers and installation could be immediate rather than waiting for the next budget cycle.
“The benefits of this – clear, consistent warning to motorists, reduced reliance on volunteers in dangerous weather, improved safety for volunteers and wildlife, lower longer-term cost than seasonal manual signage, and can be implemented this nesting season,” Ms Burrows said.
Fellow WWW member Steve Shaw also claimed the group did not support the proposed underpass at Progress Drive because it did not address actual mortality hotspots.
“Volunteer data shows turtles have not been crossing at the proposed location in recent years … Turtles will continue crossing at the known hotspots and mortality will continue,” he said.
“Hope Road is the primary mortality hotspot … Five turtles have already been killed here in 2026, even after speed limit reduction. Last one was last week.
“WWW proposes restoring the unnecessary stretch of Hope Road as a wildlife corridor, expanding the Row 8 rehabilitation area. This would protect the turtles and all wetland wildlife, support cultural and ecological restoration, provide safe movement pathway and nesting habitat, create black cockatoo habitat.”
Councillors passed the officer recommendation unanimously en bloc, planning to develop a temporary traffic management plan as part of the 2027-28 annual budget process. This is expected to cost about $75,000 including public consultations and traffic management.
The speed limit reduction trial includes a 1.3km stretch of Hope Road between Progress Drive and Bibra Drive, and a 2.7km stretch of Bibra Drive between Progress Drive and Hope Road lowered to 50km/h. The speed limit along 2.3km of Progress Drive between Hope Road and Bibra Drive would be reduced to 40km/h.
A report detailing trial outcomes, community feedback and a proposed way forward will be presented to council for consideration following completion of the trial.
Director of sustainable development and safety Dan Arndt said the underpass proposal would be the first of its kind in the city.
“Data already available from the 2025 Turtle Monitoring Report, TurtleSAT citizen science app and city and community observations show local hotspots where female turtles are often killed due to vehicle strike as they cross busy roads in search of nesting grounds,” he said.
“(The underpass) is proposed for the narrowest area of the Bibra Lake bank, between the northern retaining wall and Hope Road, allowing turtle access to nesting habitat in bushland west of Progress Drive without having to traverse busy parklands, shared paths and roads.”
Murdoch University’s March turtle population report noted the underpass as a significant conservation opportunity to monitor microchipped turtles in Bibra Lake.
The report also recognised turtle vulnerability to predation and road mortality, resulting in a male-dominated population and low number of juveniles.
