Each permit for making an opening shall be confined to a single project and shall be issued by the authorized city official. Application shall be made on a form prescribed by the legislative body, giving the exact location of the proposed opening, the kind of paving, the area and depth to be excavated and such other facts as may be provided for. The permit shall be issued only after a cash deposit sufficient to cover the cost of restoration has been posted with the authorized city official, conditioned upon prompt and satisfactory refilling of excavations and restoration of all surfaces disturbed.
(`96 Code, § 91.21)