The following shall be exempt from the requirement of a conditional use permit:
(A) Excavations for a swimming pool, or for the foundations or basement of any building for which a building permit has been issued.
(B) Grading of any parcel of land for a permitted use where no bank is left standing and exposed of more than 10 feet in vertical height, or when less than 1,000 cubic yards of earth are removed from the premises.
(C) Grading in a subdivision which has been approved by the city.
('64 Code, § 60.13)