According to CQ News, Jericho grazier Bruce Currie said it could take two months before the court makes a decision.
“Our groundwater should be protected before this mine can go ahead," Currie reportedly said.
"I'm confident it can be achieved, I'm not saying it will be achieved."
A GVK Hancock spokesman reportedly said the JV was confident it demonstrated to the court that it should recommend the mining lease and environmental authority be granted.
Proceedings of the appeal to the Land Court made by Queensland farmers and an environmental group started in September, with some testimony heard via video link from Emerald.
The vast thermal coal project had won federal government approval in the previous month.
The proposed mine is targeting 32 million tonnes per annum of production with first exports in 2017.
GVK Hancock is a joint venture between Indian conglomerate GVK and billionaire Gina Rinehart-led Hancock Coal.