The permittee shall at all times and at his or its own expense preserve and protect from injury any adjoining property by providing proper foundations and taking other measures suitable for the purpose. Where in the protection of such property it is necessary to enter upon private property for the purpose of taking appropriate protecting measures, the permittee shall obtain, a license from the owner of such private property for such purpose and, if he cannot obtain a license from such owner, the administrative authority may authorize him to enter the private premises solely for the purpose of making the property safe. The permittee shall, at its own expense, shore up and protect all buildings, walls, fences or other property likely to be damaged during the progress of the excavation work, and shall be responsible for all damage to public or private property or highways resulting from its failure to properly protect and carry out said work. Whenever it may be necessary for the permittee to trench through any lawn area, the sod shall be carefully cut and rolled and replaced after ditches have been backfilled as required in this chapter. All construction and maintenance work shall be done in a manner calculated to leave the lawn area clean of earth and debris and in a condition as nearly as possible like that which existed before such work began. The permittee shall not remove, even temporarily, any trees or shrubs which exist in parking strip areas without first obtaining the consent of the appropriate city department or city official having control of such property. (Ord. 106 §13, 1961).