Documents obtained by the

The bridge was built at a cost of $49million and was supposed to guarantee access between Wollongong’s northern suburbs.

But seven years later, the State Government is again being asked to pay for remediation work and potentially close the road as an area near the bridge’s northern end is slipping into the ocean.

Only 5m from a footpath and 20m from the road, it has deteriorated, forcing the Government to dump boulders and rocks at the base while it considers options.

The most likely long-term solution is building an 80m sea wall to buttress the land and stop it from slipping further, which would a be costly and disruptive.

Roads Minister Duncan Gay would not say whether the road would have to be closed during the work, however a senior engineer said it was ‘‘inevitable’’ there would be disruption.

‘‘A preferred option has not yet been selected and costs are not known, but repairs are expected to be above $10 million,’’ a spokesman for Mr Gay said.

‘‘The community will be kept informed ... and remedial work will be carefully planned to ensure impacts on the community are kept to a minimum.’’

A report by geotechnical engineers AECOM said the planners behind the bridge had canvassed the idea of a longer bridge which avoided the problem area known as the northern amphitheatre.

It is unclear how much a longer bridge would have cost.

However, the idea was dumped, with designers instead preferring to ‘‘reuse the current road alignment’’ despite the ‘‘higher (but acceptable) road user risk’’.

The area is particularly vulnerable to landslip, with some areas having moved 1.5m since 2006.

The bridge was constructed by RMS engineers, with AECOM, Coffey and Barclay Mowlem, now trading as Laing O’Rourke.

The consortium was collectively known as the Lawrence Hargrave Drive Link.

AECOM and Coffey declined to comment, preferring instead for RMS to speak on their behalf.

Laing O’Rourke did not respond to questions.

An RMS spokeswoman said during design of the bridge, the concern was material falling above the road, ‘‘not slips below’’.

But the AECOM report refers to ‘‘known old landslides on the downhill side of the road embankment within the northern amphitheatre [which were] not stabilised ... due to the high cost of coastal protection works’’.

David Campbell, who was Member for Keira at the time, did not recall any discussions about building a longer bridge.

‘‘I pushed as hard as I could for a long-term solution there and that is what we got,’’ he said.

Dr Phil Flentje, an engineer involved in the early design phase, said a longer structure which avoided landslip areas was discussed but dismissed because it was too expensive.

‘‘There was an option for a longer bridge, but at the time I was involved we were not looking at budgets anywhere near that bridge option,’’ he said.

He believes remediation works will involve road ‘‘disruption’’.

‘‘It is inevitable there will be some disruptions if work is required but not on the scale of the Sea Cliff Bridge,’’ he said.

Clifton resident Wayne Gordon, said it was ‘‘extremely important’’ to keep the road open, but roadworks and landslip were accepted as part of living in the area.

‘‘You have to accept that the landscape is such that these things have to be done every now and then,’’ he said.

Ruth Tsai felt more should have been spent on the bridge to save costlier works later.