All persons to whom such permits are granted shall be personally responsible for the maintenance and repair of the street surface or pavement cut, dug up, damaged, tunneled under, or undermined under the provisions of said permits, in as good as or better condition than before such work was undertaken, at their own expense and for such period of time as may be required by the City Engineer, but not to exceed two (2) years. (Ord. 1700 § 10, amended, 1971)