For purposes of this section, "qualified conservation contribution" means the just value, as determined by a real estate appraiser as defined under Title 32, section 14002, subsection 13, of any land or interest in land, including a conservation easement on land, that has been conveyed without financial consideration, or the value of any discount of the sale price in any sale of land or interest in land, to the State, a political subdivision of the State, a water district as defined under Title 35-A, section 6101, subsection 3 or a qualified organization as defined under Section 170(h) of the Code if such land is to be permanently preserved or used as a public water supply source.