The unfolding erosion catastrophe at Stockton was forecast more than four decades ago when state government engineers studied sand movements in Stockton Bight as part of a feasibility report into creating an artificial harbour at Williamtown.
The engineers' reports showed the beach was continually receding as a result of the natural movement of sand northwards.
"Hydrosurvey data available over 126 years for the southwestern end of the bight indicates recessions of between 0 and 1.2 metres per year, whilst aerial photographs of the entire bight for the period 1938-76 show average beach and foredune recession rates of between 1 and three metres per year," a conference paper presented at the 1977 Australian Conference on Coastal and Ocean Engineering said.
Given the huge costs associated with cutting through a rock bar situated at the harbour entrance, the government was keen to explore options for an alternative port for bulk cargo vessels at either Port Stephens or Williamtown.
The Williamtown option would have involved creating a port entrance near the site of the former Sygna wreck.
The sand movement modelling was used to estimate how the beach would react to the construction of a new breakwater at the site.
The government abandoned the project and proceed with the harbour deepening project. But the information about the impending risk to Stockton was largely ignored until recently.
Coastal engineer Angus Gordon, who worked on the 1970s project, said the situation at Stockton presented similar coastal engineering challenges to those faced at Collaroy, Bate Bay and Jimmys Beach.
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The jury is still out on the success of a recently installed sand transfer system that pumps sand from the entrance to the Myall River and deposits it at 10 points along Jimmys Beach.
But with an estimated cost of between $10 and $30 per cubic metre of sand, it unlikely that a similar system could be used at Stockton.
Mr Gordon said Bate Bay could be considered a miniature version of Stockton.
"At Bate Bay we were able to stabilise the foredunes over the entire embayment and as a result erosion of a similar magnitude to that at Newcastle Bight was overcome and the shoreline is now relatively stable, though it requires constant maintenance," he said.
He believes the most practical long-term solution for Stockton would be the creation of a large groyne, possibly near the former hospital site to counteract the impact of the northern harbour breakwall.
"I suspect a rock wall will end up being the answer with the associated loss of the beach and need for a north end "return" to manage the outflanking as the beach to the north continues to recede," he said.
