Nothing in this act shall be construed to prevent any department, board or commission of the State government from purchasing, condemning or otherwise acquiring the absolute right of support for any lands, easements or right of ways purchased, condemned or acquired in the name of the Commonwealth, and damages sustained by the owner of underlying coal or the person entitled to remove the same shall be determined and paid in accordance with existing laws relating to the purchase, condemnation or other acquisition of lands, easements and right of ways by the Commonwealth.