A county board of commissioners may permit or prohibit within that county the construction of any bridge over or across any navigable stream. They shall also have power to provide for the removal of any obstruction arising from the erection of booms or the collecting of logs or rafts in such streams, by any individual; and to direct the time in which, and places where, persons having logs, rafts and boats in such streams shall be allowed to remain, and when the logs, rafts, and boats shall be removed. A county board of commissioners may impose any penalties as they consider necessary to enforce regulations issued under this section, and may authorize the sheriffs or their deputies to carry into effect the regulations made under this act.