In any case where any person or persons have been authorized by act of assembly to build a pier in any of the rivers of this state, and to connect the same with the shore by means of sticks of timber, it shall be lawful for such person or persons, their heirs and assigns, notwithstanding any provision in any of such acts of assembly to the contrary, to so locate such pier, and connect the same with the shore by means of sticks of timber, as shall best answer their purposes: Provided, That any change in the location of such pier shall be limited within a radius of one hundred feet in any direction of the original location as heretofore fixed by law: Provided also, That such pier in its changed location shall not interfere with the navigation of said river, nor in any way injure private property: And provided further, That the provisions of this act shall not apply to any case in which litigation may be now pending: And provided further, That no such pier shall be so located and connected with the shore in rivers where port wardens are created by law, unless by the direction and consent of said port wardens.¹