An independent assessment of a plan to repurpose disused Upper Hunter mining voids into a series of interconnected lakes has found the proposal could be a driver in the region's post-mining economy.
The group behind the scheme, the Hunter Lakes Corporation, is now pushing for government funding for a feasibility study.
If realised, the scheme would see at least four mining voids linked together to create large-scale water storage and tourism projects.
It is based on similar projects in Lusatia, Germany and Lake Kepwari in Western Australia.
The University of Newcastle's Centre for Water and Land was commissioned to critically review the scheme in the context of what had been learnt from existing projects.
This included reviewing the key issues of water balance, salinity and contamination and their impact on the water table and the wider Hunter River catchment.
It found that potential salinity and contamination issues, which are commonly raised as obstacles to the creation of man-made lakes, could be addressed with existing technologies.
However, it recommended more research was needed on the critical issue of water availability.
"This included research into the costs and benefits of increasing the catchment area of each void to increase the amount of precipitation entering the voids," the proof of concept study said.
"The research should include an assessment of the costs and benefits for both the scheme and other water users in the Upper Hunter including the environment, of altering what happens to precipitation after it falls on the area surrounding the voids."
Research was also needed into methods of reducing evaporation from the voids. Possible solutions include the use of floating solar panels, adding anti-evaporation agents to the water and the use of aquacaps.
Hunter Lakes Corporation director Greg Story has called on the state and federal governments to provide $10 million to allow a feasibility study for the project using one of the smaller voids.
"We're not saying that there aren't issues that will need to be addressed, but the proof of concept study shows that this can happen," Mr Story said.
"Sooner or later those voids will need to be remediated. Our argument is let's get cracking and turn this into an economic benefit for the region."
The project has garnered letters of support from 40 groups and individuals including business organisations, Hunter MPs and First Nations groups.
"We have focused on ensuring all direct and secondary stakeholders are not only fully apprised of the Hunter Lakes Scheme but also afforded the opportunity to participate in its design and formulation," Mr Story said.
The German-Australian Chamber of Industry and Commerce is also hosting a stakeholder tour of Germany's artificial lakes in June.
Hunter federal MP Dan Repacholi said water security, mine site rehabilitation and regional long-term economic opportunity were critical concerns of the Hunter community.
"The Hunter Lakes Scheme seeks to use existing coal mine voids in the Hunter for water storage and create an integrated network of interconnected lakes from Muswellbrook to Broke," he said.
"The intent of this scheme is to provide water security, economic security, and improved amenity.
"The additional benefits are many and include long term employment opportunities, urban renewal, renewable energy transition, and beneficial inter-generational environmental outcomes."
Upper Hunter state MP Dave Layzell said he was supportive of any plans for reusing mining lands for new purposes. However, he was agnostic in relation to individual plans.
"I do not prefer one plan over the other at this stage. I am open to them all. That being said, the Hunter Lakes plan is certainly a fascinating idea," he said.
"The reuse of mining land for productive purposes is a really important goal for the entire Hunter Valley."
