The federal government has approved a massive coal mining project in central Queensland that will be the largest in the country.

Environment Minister Greg Hunt approved the 37,380 hectare Kevin's Corner project on Friday.

The mine, to be operated by a joint India-Australia consortium, GVK-Hancock, is the first to be approved since the introduction of a new water trigger rule by the previous federal government.

Greenpeace claims Kevin's Corner will use more than nine billion litres of water a year and the Lock the Gate Alliance says more information on its impact on Galilee Basin groundwater is needed.

Water science experts urged Mr Hunt to reject any mining proposals that would adversely impact water supplies.