When the construction or proposed construction of said railroad affects the value of improvements on state lands not situated on the right-of-way or extra widths, the applicant for said right-of-way shall file with the department a valid release of damages duly executed by the owner or owners of such improvements, or a certified copy of a judgment of a court of competent jurisdiction, showing that compensation for the damages resulting to such owner or owners, as ascertained in accordance with existing law, has been made or paid into the registry of such court.