An official geotechnical assessment six years ago of the Kings Highway at Clyde Mountain – now closed for five days because of a 1400-tonne landslide – found there was a ‘‘low potential’’ for the mountainside to collapse even under extreme weather conditions, given existing protective fences and mesh.
The closure on Friday of the main road for people in Canberra, Queanbeyan, Braidwood and other surrounding inland towns to get to the south coast has caused travel chaos for families hoping to spend the school holidays at the beachside before the harsh winter.
Businesses, such as motels, restaurants and cafes, on the south coast and at inland towns such as Braidwood, which depend on passing trade, have lost income as holidaymakers cancelled trips.
In response to questions put by The Canberra Times to the NSW Roads and Maritime Services yesterday, the agency revealed it had identified the potential for a rock fall in an assessment conducted in 2006.
‘‘The risk assessment considered both how the mountainside might fail and the likelihood of a rock fall,’’ an RMS spokeswoman said. ‘‘It was assessed as low potential for failure, given the already extensive fences and mesh draping on the site.
‘‘All assessments carried out by the RMS take into account the variety of extreme weather conditions.’’
The NSW government agency defended its decision to rank the risk to Kings Highway as low, arguing the area near Pooh Bear corner, west of Nelligen, already had a large rock-catch fence and mesh draping that had ‘‘proved suitable for the majority and more prevalent rock falls’’ in the area.
‘‘These large events are rare and difficult to predict. They are even more difficult to design cost effective treatments for.’
Still, the agency will be ‘‘carrying out a much more comprehensive assessment’’ once the road has been re-opened.
This would review the ‘‘assessed risk of the site and the suitability’’ of existing protections.
In Batemans Bay, the owner of the Bayside Motel, Guy Smith, said yesterday he had several cancellations on the weekend and a restaurant his daughter’s partner operated further down the coast, in Bodalla, had a ‘‘very quiet weekend, where every other weekend has been busy, busy, busy’’.
‘‘It is a combination of the road closure, which has had a substantial impact, but also the way the weather has been, which in effect caused the problem in the first place,’’ Mr Smith said.
The RMS spokeswoman said the Kings Highway was expected to be re-opened by the end of the week subject to the availability of ‘‘required building materials’’.
‘‘The cost of repairs is still being established,’’ she said.
Motorists are being diverted at Braidwood and Batemans Bay.