An extensive two year Geotechnical Hazard Study is underway on Seal Rocks Road to assess the road’s stability after a number of landslips over the last decade.
The study is being conducted by our consultants, Coffey Services Australia.
Why are we doing this?
The exposure of the Seal Rocks Road and nearby parking infrastructure to coastal hazards and increasing pressure from visitors means that there are concerns for the stability of the road.
Landslips have previously occurred during weather events:
- in two locations – one on Seal Rocks Road and one on Kinka Road in February 2020
- opposite the driveway for 56 Kinka Road on 17 November 2013
- on Kinka Road on a steep section of road on 21 July 2011 during heavy rain
- another 50 metres south of that site in approximately 2008.
As there is only one road route in and out of Seal Rocks, a future failure could possibly isolate the town and cause hardship for residents during weather events or other disasters.
It’s vital that we maintain a secure future road access to the Seal Rocks village.
Of high concern is that the coastal hazards and the improper use of the road infrastructure lead to degradation of the road, increased erosion and reduced slope stability.
What does the Hazard Study include?
The consultants are undertaking several assessments to complete the study, which will take several months to complete.
These elements include:
- site investigations – geotechnical drilling (complete), ground penetrating radar, multi-channel analysis of surface waves technique and Dynamic Cone Penetrometer (using a thin steel rod to locate rock below the surface).
- review of existing relevant documentation and data
- assessment of future conditions affecting the shoreline including erosion and sea level rise.
What will happen next?
Once the geotechnical hazard study is complete, we will work with the consultants to develop options for a possible realignment of Seal Rocks Road.
There will be a community consultation on viable relocation options.
Following that, we will then work with the community to develop a road realignment plan for Seal Rocks to guide future planning for the village and identify improvements and opportunities after the road realignment.
We are committed to keeping the community fully informed of this project and the findings of the studies.
Throughout the entire project, we will be partnering with the consultants to work closely with the Seal Rocks community, Aboriginal Land Councils and community, NSW National Parks and Wildlife Service, the NSW Department of Planning, Industry and the Environment – Lands and other local stakeholders.
Environmental values and Aboriginal heritage will be included in the studies to ensure we are considering the future impacts of present day decision making.
This is expected to take place over the next two or three years. We will update this page as the project progresses.
Below are some key questions about the study.
Yes. Landslips on Seal Rocks Road are increasing in frequency, and the risk of a larger landslip that would cut the road for an extended period of time is a possibility.
Council has a responsibility to ensure adequate road access to the Seal Rocks community for provision of essential services and access to properties.
Borehole drilling involves drilling a 100mm vertical hole (intrusion) into the ground with an auger to extract a core of rock which will then be tested in a lab to determine the ground type and conditions. There is minimal environmental risk to this operation as no other ground will be disturbed outside of the test area. Once the drilling is complete the ground will be reinstated with the excavated cuttings to the approximate original ground level.
Will the hazard study for Seal Rocks Road include the likelihood and impact of extreme weather events (like coastal storm inundation and fire hazard) on the road?
The study will definitely include an analysis of coastal storm impacts on the road. Fires do not affect the road, but rather accessibility of the road at certain times, which at this point is beyond the scope of this particular assessment.