Expert says sand supply off Stockton, that could potentially be used to fix beach, so abundant it's like an 'underwater desert'

It's understood Deputy Premier John Barilaro will visit Stockton this month with an update on investigations.

While there are still huge roadblocks to overcome, the state government has not ruled out lifting a ban on offshore dredging as a means of sourcing sand to replenish Stockton beach that has been crippled by erosion over decades.

As Resources Minister, Mr Barilaro oversees the ban on offshore dredging in NSW.

A spokeswoman for Mr Barilaro said on Wednesday that detail about the work done by the Geological Survey of NSW, based at Maitland, would be made public in coming weeks

"The Deputy Premier's resources agency has drawn together excellent work which aims to identify sources of sand around Stockton that might be suitable for beach nourishment," she said.

"This has been a priority project for the Deputy Premier since he announced the establishment of his Stockton Beach Taskforce."

READ MORE: The Herald's coverage of the Stockton erosion crisis

While offshore dredging is not technically illegal in NSW, it does require a mining lease because sand is considered a mineral.

As a state significant development it also requires a development consent.

City of Newcastle's much-anticipated Stockton Coastal Management Program (CMP) went on public exhibition this week, identifying offshore sand nourishment as the only viable solution to get enough sand back on the beach.

Newcastle University's Conjoint Associate Professor in Earth Sciences Ron Boyd, who has researched sand supply off Stockton, said there was more than enough to provide what was needed to replenish the beach.

"It's like a desert with water on top of it, from the large sand mound located off Nobbys to Birubi," he said.

"Three to six metres of sand has already been penetrated by previous bore holes... There is a very large volume of sand out there, it really is just about identifying the best place."

It's estimated Stockton needs between 1.8 million cubic metres and 4.5 million cubic metres of sand to renourish the beach from the breakwater to the Hunter Water land north of Corroba Oval.

One of the biggest costs of offshore sand nourishment is mobilising a specialist dredge capable of doing the job, estimated at between $2 million and $8 million.

Associate Professor Boyd said Stockton was just one of at least 16 erosion hot spots identified in NSW that could benefit from offshore sand nourishment.

He said the process would be made more cost effective if the NSW and Queensland governments coordinated the mobilisation of a dredge so the cost was shared.

In 2017, an offshore dredging program saw three million cubic metres of sand pumped onto Gold Coast beaches to combat erosion. It took about four months, cost $13.9 million and moved enough sand to fill 15,000 Olympic swimming pools onto five beaches.

The problem in Queensland has links to the Tweed River breakwaters, built by the NSW government in the 1960s - that just like the Newcastle harbour breakwaters - trap sand travelling north. The result, just like in Stockton, is a major erosion problem on popular Gold Coast beaches.

Associate Professor Boyd said there was currently no "good environmental options approved" in NSW for replacing the amount of sand lost off Stockton due to the port operations.

"While Stockton is only one area that desperately needs sand, it is one of the worst," he said.

"Under this model the sand would only be taken from a couple of kilometres offshore, so you are taking sand that is already in the system. You are not digging it up from somewhere and removing it."

A report by consultants Royal HaskoningDHV, prepared as part of the CMP, identified a range of sand sources that could be used at Stockton.

These ranged from approved techniques, like quarries and sand scraping, to prohibited operations like offshore dredging.

According to the report, even if the ban can be overturned, there are still significant roadblocks to offshore dredging.

These include identifying a sand source, verifying the sand source with surveys, licences and approvals and assessment of environmental impacts.

The report also identified a range of "potentially feasible" sand sources including from Sydney tunnelling works, pumping sand from Stockton Bight and dredging works in Newcastle Harbour if the proposed gas terminal is approved.

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