A grading permit is not required for any of the following work that is carried out on an individual tract of land or on a single lot within a subdivision:
1. An excavation below finished grade for basements and footings of a building, retaining wall or other structure authorized by a valid building permit. This shall not exempt any fill made with the material from such excavation if the fill meets any requirements of Section 159A.02(1) above.
2. Cemetery graves.
3. Any work requiring a conditional use or special use permit.
4. Gardening and landscaping.
5. Farming.
6. Exploratory excavations under the direction of soil engineers or engineering geologists, or in connection with an environmental, archaeological, or paleontological investigation, or mitigation.
7. Any State or Federal improvement project which has been approved by the Council for the City.