Disused mining voids beneath prime commercial real estate in Lake Macquarie are set to be filled with thousands of tonnes of cement grout, paving the way for future growth and development.

The Federal Government announced on Friday 10 May a $10 million Lake Macquarie Mines Grouting Fund to help cover the cost of filling the sometimes-cavernous voids left behind by historic coal mines across the Lake Macquarie local government area.

The funding will arrive in two stages, with the first $2 million spent setting up the fund in conjunction with Lake Macquarie City Council, and the remaining $8 million available for future development requiring grouting works.

Suburbs expected to benefit most include Charlestown, Cardiff, Morisset, Glendale and West Wallsend, all of which are extensively undermined.

Council’s Director Development Planning and Regulation David Antcliff said that while some old coal mines tunnelled deep beneath the earth’s surface, others were relatively shallow.

“Mines left behind may become unstable if large-scale developments are built on top of them,” he said.

“That’s where mine grouting becomes necessary.”

Grouting involves pumping a cement-like material into the void. Some cost hundreds of thousands of dollars and require thousands of cubic metres to fill, potentially making the development a commercially unviable undertaking without external assistance.

Mr Antcliff said six recent local mine grouting projects each required an average of about 8750 cubic metres of cement to fill.

The largest void alone sucked up 25,000 cubic metres of cement, enough to fill 10 Olympic swimming pools.

“The Mines Grouting Fund will contribute to these often-prohibitive costs,” Mr Antcliff said.

“That not only provides certainty for developers and investors, it ensures development in Lake Mac is undertaken safely and without the threat of future mine subsidence.”

Lake Macquarie Mayor Kay Fraser said mine grouting would open the door for an estimated $450 million of development in the city, close to shops, services and transport links.

“Time and again, our studies and strategies have identified the need for higher density development in commercial centres to cater for the city’s projected growth,” she said.

“But some of that land sits on top of old mines. Funding for mine grouting will help unlock the development potential of these sites, creating jobs, providing new homes and attracting more investment in our city.”

Dantia CEO Tim Browne said the federal funding provided a key pillar to continued investment and growth in the city’s urban centres.

“This financial support will put Lake Macquarie on an even playing field with other areas not affected by historical mining operations, developing new and innovative industries and providing an environment that will increase investment and jobs,” he said.