From and after the passage of this act, whenever the power or manufacturing or mining plant of any company, heretofore or hereafter incorporated under the laws of the Commonwealth of Pennsylvania, is situated upon or near the bank of any navigable stream within this Commonwealth, and such company has the right, either as the owner in fee or by lease or other arrangements, to mine coal from or under lands adjoining or adjacent to the opposite bank of said navigable stream, or is the owner of a majority of the capital stock of any company that has the right, either as owner in fee or by lease or other arrangement, to mine coal from or under lands adjoining or adjacent to such opposite bank of said navigable stream, such company shall have the right and lawful authority to construct, operate, and maintain tunnels under said navigable stream, so as to connect said coal lands, and any mine operated in connection with said coal lands, with said power or mining plant of said company: Provided, however, Before any company begins the construction of any tunnel, it shall make application to, and secure the approval of, the Water and Power Resources Board¹ or such other authority as shall, at the time of such application, have jurisdiction over navigable streams under the laws of the Commonwealth of Pennsylvania the same as now vested in said Water and Power Resources Board: Provided, however, That said corporation or corporations, constructing said tunnel or tunnels, shall pay to the Commonwealth of Pennsylvania the fair market value for all coal mined in constructing said tunnel or tunnels.