(a) The average grade of each lot in the Municipality except as otherwise provided, is established at not to exceed fifteen inches above the average established grade of that section of the street or streets on which the lot abuts. No artificial grading of any lot shall be made which will increase the height of any part of the grade thereof in such a manner that any part so graded is in excess of fifteen inches above the established average grade of the street along the line or lines bounding the lot. Wherever the average natural grade of any lot, as determined by the Building Inspector, is above the lot grade established, then the average natural grade may be maintained for the lot.
(b) In the event that the topography of any land is such that the lot grade established would, in the opinion of the Building Inspector, work an injustice upon the owner or would render the improvement or development of the land difficult and impractical, the Inspector with the written consent and approval of the Building Committee of the Council, may grant a special permit establishing a different lot grade than that herein established.
(1973 Code Section 151.20.)