Any moneys authorized for the program may be expended with matching funds from: (1) Private contributions of cash or securities, in an amount not less than fifteen per cent; (2) moneys from a federal matching program, subject to the limitations of applicable federal and state laws, in an amount authorized by said federal program; (3) contributions of real property, or interest therein, that serves recreational and natural heritage land acquisition needs of the department as determined by the commissioner; (4) municipal contributions of cash or securities, in an amount not less than fifteen per cent, provided contributions from municipalities, nonprofit entities and water companies shall be derived from a source other than state grant moneys obtained from the open space and watershed land acquisition grant program; or (5) any combination thereof. Contributions of land or interest in land shall be valued, for purposes of this section, in the amount of their appraised value.