RMS is continuing to closely monitor the embankment slip in the northern amphitheatre. The road remains safe and stable.

During March RMS detected further movement in the slip, with movement of around two metres. Real time monitoring equipment indicated the water level in the embankment was high, contributing to the movement.

While the water pressure will naturally decrease, installing wells will decrease the water pressure more quickly and help to increase stability in the embankment, reducing the likelihood of any further movement. For more information on this please click here.

The water pressure in the embankment has risen more than 5.5 metres since the start of the year. This is due to the higher than average rainfall.

Rainfall data from RMS' real time monitoring at the site indicates the area has received 890mm of rainfall this year. This is more than 60 per cent of the total yearly rainfall for this area. February was 2.5 times wetter than average and rainfall during March is already 1.6 times the average. This is based on Bureau for Meteorology data from Wombarra.

Once the water pressure in the embankment decreases, work will start on building an access track in on eastern side of the road. This will provide the access needed to place rocks or boulders at the base of the embankment to help minimise the impact of sea erosion.

We will keep you updated as the drilling of the wells progresses and the water pressure lowers.  

If you would like further information please contact our project manager.

Background

Slippages are a characteristic of this area on Lawrence Hargrave Drive because of its exposure to the ocean and the unstable geology.  RMS has been monitoring and treating instability along Lawrence Hargrave Drive for many years.

Shorter term repair work

While an overall plan to manage the embankment instability is still being developed, shorter term repair work will be done to help minimise the impact of sea erosion at the base of the embankment.

This is likely to consist of rocks and boulders placed at the base of the slip to provide protection from wave action.

While we expected to start construction of the access track for this work in the northern amphitheatre in March, this has been delayed due to the high water pressure level in the embankment

What happens next?

RMS has called tenders for a contractor to undertake the erosion protection work. Once the successful tenderer has been awarded, and the stability of the slope is improved, work will start on the protection works at the base of the embankment.

More detailed technical information on the stability in this area is expected in mid 2012. This will provide the information needed to develop a plan to effectively manage the embankment instability. This plan is expected to be finalised in the second half of 2012.

We will be keeping the community informed as more detailed information becomes available.

To view or download frequently asked questions, click here.